Initial commit

vs4win/Chapter09/Ch09Ex02SerializingShapes/Ch09Ex02SerializingShapes.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vs4win/Chapter09/Ch09Ex02SerializingShapes/Circle.cs

@@ -0,0 +1,14 @@
+namespace Packt.Shared;
+
+public class Circle : Shape
+{
+  public override double Area
+  {
+    get
+    {
+      return Math.PI * Radius * Radius;
+    }
+  }
+
+  public double Radius { get; set; }
+}

vs4win/Chapter09/Ch09Ex02SerializingShapes/Program.cs

@@ -0,0 +1,50 @@
+using Packt.Shared; // Circle, Rectangle, Shape
+using System.Xml.Serialization; // XmlSerializer
+
+using static System.Environment;
+using static System.IO.Path;
+
+// create a file path to write to
+string path = Combine(CurrentDirectory, "shapes.xml");
+
+// create a list of Shape objects to serialize
+List<Shape> listOfShapes = new()
+{
+  new Circle { Colour = "Red", Radius = 2.5 },
+  new Rectangle { Colour = "Blue", Height = 20.0, Width = 10.0 },
+  new Circle { Colour = "Green", Radius = 8 },
+  new Circle { Colour = "Purple", Radius = 12.3 },
+  new Rectangle { Colour = "Blue", Height = 45.0, Width = 18.0 }
+};
+
+// create an object that knows how to serialize and deserialize 
+// a list of Shape objects
+XmlSerializer serializerXml = new(listOfShapes.GetType());
+
+WriteLine("Saving shapes to XML file:");
+
+using (FileStream fileXml = File.Create(path))
+{
+  serializerXml.Serialize(fileXml, listOfShapes);
+}
+
+WriteLine("Loading shapes from XML file:");
+List<Shape>? loadedShapesXml = null;
+
+using (FileStream fileXml = File.Open(path, FileMode.Open))
+{
+  loadedShapesXml =
+    serializerXml.Deserialize(fileXml) as List<Shape>;
+}
+
+if (loadedShapesXml == null)
+{
+  WriteLine($"{nameof(loadedShapesXml)} is empty.");
+}
+else
+{
+  foreach (Shape item in loadedShapesXml)
+  {
+    WriteLine($"{item.GetType().Name} is {item.Colour} and has an area of {item.Area:N2}");
+  }
+}

vs4win/Chapter09/Ch09Ex02SerializingShapes/Rectangle.cs

@@ -0,0 +1,15 @@
+namespace Packt.Shared;
+
+public class Rectangle : Shape
+{
+  public override double Area
+  {
+    get
+    {
+      return Height * Width;
+    }
+  }
+
+  public double Height { get; set; }
+  public double Width { get; set; }
+}

vs4win/Chapter09/Ch09Ex02SerializingShapes/Shape.cs

@@ -0,0 +1,11 @@
+using System.Xml.Serialization;
+
+namespace Packt.Shared;
+
+[XmlInclude(typeof(Circle))]
+[XmlInclude(typeof(Rectangle))]
+public abstract class Shape
+{
+  public string? Colour { get; set; }
+  public abstract double Area { get; }
+}

vs4win/Chapter09/Chapter09.sln

@@ -0,0 +1,55 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.2.32210.308
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WorkingWithFileSystems", "WorkingWithFileSystems\WorkingWithFileSystems.csproj", "{FCC1830B-5341-4ED6-B9B3-1885B1724D6E}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WorkingWithStreams", "WorkingWithStreams\WorkingWithStreams.csproj", "{3D9CAC15-E6F2-462E-9821-45BEF1A76326}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WorkingWithEncodings", "WorkingWithEncodings\WorkingWithEncodings.csproj", "{70A9750E-5C55-4879-B601-20AC5F6CDCB4}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WorkingWithSerialization", "WorkingWithSerialization\WorkingWithSerialization.csproj", "{7493AA42-910F-4FB2-B3D4-34553255BD54}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WorkingWithJson", "WorkingWithJson\WorkingWithJson.csproj", "{CA13AF96-7EE4-42C4-A671-C373E218726A}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Ch09Ex02SerializingShapes", "Ch09Ex02SerializingShapes\Ch09Ex02SerializingShapes.csproj", "{27FA94CC-1856-4512-9D09-0214CF846311}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{FCC1830B-5341-4ED6-B9B3-1885B1724D6E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FCC1830B-5341-4ED6-B9B3-1885B1724D6E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FCC1830B-5341-4ED6-B9B3-1885B1724D6E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FCC1830B-5341-4ED6-B9B3-1885B1724D6E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3D9CAC15-E6F2-462E-9821-45BEF1A76326}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3D9CAC15-E6F2-462E-9821-45BEF1A76326}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3D9CAC15-E6F2-462E-9821-45BEF1A76326}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3D9CAC15-E6F2-462E-9821-45BEF1A76326}.Release|Any CPU.Build.0 = Release|Any CPU
+		{70A9750E-5C55-4879-B601-20AC5F6CDCB4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{70A9750E-5C55-4879-B601-20AC5F6CDCB4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{70A9750E-5C55-4879-B601-20AC5F6CDCB4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{70A9750E-5C55-4879-B601-20AC5F6CDCB4}.Release|Any CPU.Build.0 = Release|Any CPU
+		{7493AA42-910F-4FB2-B3D4-34553255BD54}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7493AA42-910F-4FB2-B3D4-34553255BD54}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7493AA42-910F-4FB2-B3D4-34553255BD54}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7493AA42-910F-4FB2-B3D4-34553255BD54}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CA13AF96-7EE4-42C4-A671-C373E218726A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CA13AF96-7EE4-42C4-A671-C373E218726A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CA13AF96-7EE4-42C4-A671-C373E218726A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CA13AF96-7EE4-42C4-A671-C373E218726A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{27FA94CC-1856-4512-9D09-0214CF846311}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{27FA94CC-1856-4512-9D09-0214CF846311}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{27FA94CC-1856-4512-9D09-0214CF846311}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{27FA94CC-1856-4512-9D09-0214CF846311}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {285FD445-B8EB-4756-9152-F155A7861DD8}
+	EndGlobalSection
+EndGlobal

vs4win/Chapter09/WorkingWithEncodings/Program.cs

@@ -0,0 +1,51 @@
+using Packt.Shared;
+using System.Text;
+
+WriteLine("Encodings");
+WriteLine("[1] ASCII");
+WriteLine("[2] UTF-7");
+WriteLine("[3] UTF-8");
+WriteLine("[4] UTF-16 (Unicode)");
+WriteLine("[5] UTF-32");
+WriteLine("[6] Latin1");
+WriteLine("[any other key] Default encoding");
+WriteLine();
+
+// choose an encoding
+Write("Press a number to choose an encoding.");
+ConsoleKey number = ReadKey(intercept: true).Key;
+WriteLine(); WriteLine();
+
+Encoding encoder = number switch
+{
+  ConsoleKey.D1 or ConsoleKey.NumPad1 => Encoding.ASCII,
+  ConsoleKey.D2 or ConsoleKey.NumPad2 => Encoding.UTF7,
+  ConsoleKey.D3 or ConsoleKey.NumPad3 => Encoding.UTF8,
+  ConsoleKey.D4 or ConsoleKey.NumPad4 => Encoding.Unicode,
+  ConsoleKey.D5 or ConsoleKey.NumPad5 => Encoding.UTF32,
+  ConsoleKey.D6 or ConsoleKey.NumPad6 => Encoding.Latin1,
+  _                                   => Encoding.Default
+};
+
+// define a string to encode
+string message = "Café £4.39";
+WriteLine($"Text to encode: {message}  Characters: {message.Length}");
+
+// encode the string into a byte array
+byte[] encoded = encoder.GetBytes(message);
+
+// check how many bytes the encoding needed
+WriteLine("{0} used {1:N0} bytes.",
+  encoder.GetType().Name, encoded.Length);
+WriteLine();
+
+// enumerate each byte 
+WriteLine($"BYTE | HEX | CHAR");
+foreach (byte b in encoded)
+{
+  WriteLine($"{b,4} | {b.ToString("X"),3} | {(char)b,4}");
+}
+
+// decode the byte array back into a string and display it
+string decoded = encoder.GetString(encoded);
+WriteLine(decoded);

vs4win/Chapter09/WorkingWithEncodings/WorkingWithEncodings.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vs4win/Chapter09/WorkingWithFileSystems/Program.Helpers.cs

@@ -0,0 +1,12 @@
+partial class Program
+{
+  static void SectionTitle(string title)
+  {
+    ConsoleColor previousColor = ForegroundColor;
+    ForegroundColor = ConsoleColor.Yellow;
+    WriteLine("*");
+    WriteLine($"* {title}");
+    WriteLine("*");
+    ForegroundColor = previousColor;
+  }
+}

vs4win/Chapter09/WorkingWithFileSystems/Program.cs

@@ -0,0 +1,132 @@
+using static System.IO.Directory;
+using static System.IO.Path;
+using static System.Environment;
+
+SectionTitle("Handling cross-platform environments and filesystems");
+
+WriteLine("{0,-33} {1}", arg0: "Path.PathSeparator",
+  arg1: PathSeparator);
+WriteLine("{0,-33} {1}", arg0: "Path.DirectorySeparatorChar",
+  arg1: DirectorySeparatorChar);
+WriteLine("{0,-33} {1}", arg0: "Directory.GetCurrentDirectory()",
+  arg1: GetCurrentDirectory());
+WriteLine("{0,-33} {1}", arg0: "Environment.CurrentDirectory",
+  arg1: CurrentDirectory);
+WriteLine("{0,-33} {1}", arg0: "Environment.SystemDirectory",
+  arg1: SystemDirectory);
+WriteLine("{0,-33} {1}", arg0: "Path.GetTempPath()",
+  arg1: GetTempPath());
+WriteLine("GetFolderPath(SpecialFolder");
+WriteLine("{0,-33} {1}", arg0: " .System)",
+  arg1: GetFolderPath(SpecialFolder.System));
+WriteLine("{0,-33} {1}", arg0: " .ApplicationData)",
+  arg1: GetFolderPath(SpecialFolder.ApplicationData));
+WriteLine("{0,-33} {1}", arg0: " .MyDocuments)",
+  arg1: GetFolderPath(SpecialFolder.MyDocuments));
+WriteLine("{0,-33} {1}", arg0: " .Personal)",
+  arg1: GetFolderPath(SpecialFolder.Personal));
+
+SectionTitle("Managing drives");
+
+WriteLine("{0,-30} | {1,-10} | {2,-7} | {3,18} | {4,18}",
+  "NAME", "TYPE", "FORMAT", "SIZE (BYTES)", "FREE SPACE");
+
+foreach (DriveInfo drive in DriveInfo.GetDrives())
+{
+  if (drive.IsReady)
+  {
+    WriteLine(
+      "{0,-30} | {1,-10} | {2,-7} | {3,18:N0} | {4,18:N0}",
+      drive.Name, drive.DriveType, drive.DriveFormat,
+      drive.TotalSize, drive.AvailableFreeSpace);
+  }
+  else
+  {
+    WriteLine("{0,-30} | {1,-10}", drive.Name, drive.DriveType);
+  }
+}
+
+SectionTitle("Managing directories");
+
+// define a directory path for a new folder
+// starting in the user's folder
+string newFolder = Combine(
+  GetFolderPath(SpecialFolder.Personal), "NewFolder");
+
+WriteLine($"Working with: {newFolder}");
+
+// check if it exists
+WriteLine($"Does it exist? {Exists(newFolder)}");
+
+// create directory 
+WriteLine("Creating it...");
+CreateDirectory(newFolder);
+WriteLine($"Does it exist? {Exists(newFolder)}");
+Write("Confirm the directory exists, and then press ENTER: ");
+ReadLine();
+
+// delete directory 
+WriteLine("Deleting it...");
+Delete(newFolder, recursive: true);
+WriteLine($"Does it exist? {Exists(newFolder)}");
+
+SectionTitle("Managing files");
+
+// define a directory path to output files
+// starting in the user's folder
+string dir = Combine(
+  GetFolderPath(SpecialFolder.Personal), "OutputFiles");
+
+CreateDirectory(dir);
+
+// define file paths
+string textFile = Combine(dir, "Dummy.txt");
+string backupFile = Combine(dir, "Dummy.bak");
+WriteLine($"Working with: {textFile}");
+
+// check if a file exists
+WriteLine($"Does it exist? {File.Exists(textFile)}");
+
+// create a new text file and write a line to it
+StreamWriter textWriter = File.CreateText(textFile);
+textWriter.WriteLine("Hello, C#!");
+textWriter.Close(); // close file and release resources
+WriteLine($"Does it exist? {File.Exists(textFile)}");
+
+// copy the file, and overwrite if it already exists
+File.Copy(sourceFileName: textFile,
+  destFileName: backupFile, overwrite: true);
+
+WriteLine(
+  $"Does {backupFile} exist? {File.Exists(backupFile)}");
+
+Write("Confirm the files exist, and then press ENTER: ");
+ReadLine();
+
+// delete file
+File.Delete(textFile);
+WriteLine($"Does it exist? {File.Exists(textFile)}");
+
+// read from the text file backup
+WriteLine($"Reading contents of {backupFile}:");
+StreamReader textReader = File.OpenText(backupFile);
+WriteLine(textReader.ReadToEnd());
+textReader.Close();
+
+SectionTitle("Managing paths");
+
+WriteLine($"Folder Name: {GetDirectoryName(textFile)}");
+WriteLine($"File Name: {GetFileName(textFile)}");
+WriteLine("File Name without Extension: {0}",
+  GetFileNameWithoutExtension(textFile));
+WriteLine($"File Extension: {GetExtension(textFile)}");
+WriteLine($"Random File Name: {GetRandomFileName()}");
+WriteLine($"Temporary File Name: {GetTempFileName()}");
+
+SectionTitle("Getting file information ");
+
+FileInfo info = new(backupFile);
+WriteLine($"{backupFile}:");
+WriteLine($"Contains {info.Length} bytes");
+WriteLine($"Last accessed {info.LastAccessTime}");
+WriteLine($"Has readonly set to {info.IsReadOnly}");

vs4win/Chapter09/WorkingWithFileSystems/WorkingWithFileSystems.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vs4win/Chapter09/WorkingWithJson/Book.cs

@@ -0,0 +1,23 @@
+using System.Text.Json.Serialization; // [JsonInclude]
+
+public class Book
+{
+  // constructor to set non-nullable property
+  public Book(string title)
+  {
+    Title = title;
+  }
+
+  // properties
+  public string Title { get; set; }
+  public string? Author { get; set; }
+
+  // fields
+  [JsonInclude] // include this field
+  public DateTime PublishDate;
+
+  [JsonInclude] // include this field
+  public DateTimeOffset Created;
+
+  public ushort Pages;
+}

vs4win/Chapter09/WorkingWithJson/Program.cs

@@ -0,0 +1,39 @@
+using System.Text.Json; // JsonSerializer
+
+using static System.Environment;
+using static System.IO.Path;
+
+Book mybook = new(title:
+  "C# 11 and .NET 7 - Modern Cross-platform Development")
+{
+  Author = "Mark J Price",
+  PublishDate = new(year: 2022, month: 11, day: 8),
+  Pages = 823,
+  Created = DateTimeOffset.UtcNow,
+};
+
+JsonSerializerOptions options = new()
+{
+  /*
+  IncludeFields = true, // includes all fields
+  PropertyNameCaseInsensitive = true,
+  WriteIndented = true,
+  PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+  */
+};
+
+string filePath = Combine(CurrentDirectory, "mybook.json");
+
+using (Stream fileStream = File.Create(filePath))
+{
+  JsonSerializer.Serialize<Book>(
+    utf8Json: fileStream, value: mybook, options);
+}
+
+WriteLine("Written {0:N0} bytes of JSON to {1}",
+  arg0: new FileInfo(filePath).Length,
+  arg1: filePath);
+WriteLine();
+
+// Display the serialized object graph 
+WriteLine(File.ReadAllText(filePath));

vs4win/Chapter09/WorkingWithJson/WorkingWithJson.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vs4win/Chapter09/WorkingWithSerialization/Person.cs

@@ -0,0 +1,26 @@
+using System.Xml.Serialization; // [XmlAttribute]
+
+namespace Packt.Shared;
+
+public class Person
+{
+  public Person() { }
+
+  public Person(decimal initialSalary)
+  {
+    Salary = initialSalary;
+  }
+
+  [XmlAttribute("fname")]
+  public string? FirstName { get; set; }
+
+  [XmlAttribute("lname")]
+  public string? LastName { get; set; }
+
+  [XmlAttribute("dob")]
+  public DateTime DateOfBirth { get; set; }
+
+  public HashSet<Person>? Children { get; set; }
+
+  protected decimal Salary { get; set; }
+}

vs4win/Chapter09/WorkingWithSerialization/Program.cs

@@ -0,0 +1,117 @@
+using System.Xml.Serialization; // XmlSerializer
+using Packt.Shared; // Person 
+using NewJson = System.Text.Json.JsonSerializer;
+
+using static System.Environment;
+using static System.IO.Path;
+
+// create an object graph
+List<Person> people = new()
+{
+  new(30000M)
+  {
+    FirstName = "Alice",
+    LastName = "Smith",
+    DateOfBirth = new(year: 1974, month: 3, day: 14)
+  },
+  new(40000M)
+  {
+    FirstName = "Bob",
+    LastName = "Jones",
+    DateOfBirth = new(year: 1969, month: 11, day: 23)
+  },
+  new(20000M)
+  {
+    FirstName = "Charlie",
+    LastName = "Cox",
+    DateOfBirth = new(year: 1984, month: 5, day: 4),
+    Children = new()
+    {
+      new(0M)
+      {
+        FirstName = "Sally",
+        LastName = "Cox",
+        DateOfBirth = new(year: 2012, month: 7, day: 12)
+      }
+    }
+  }
+};
+
+// create object that will format a List of Persons as XML
+XmlSerializer xs = new(type: people.GetType());
+
+// create a file to write to
+string path = Combine(CurrentDirectory, "people.xml");
+
+using (FileStream stream = File.Create(path))
+{
+  // serialize the object graph to the stream
+  xs.Serialize(stream, people);
+}
+
+WriteLine("Written {0:N0} bytes of XML to {1}",
+  arg0: new FileInfo(path).Length,
+  arg1: path);
+WriteLine();
+
+// Display the serialized object graph
+WriteLine(File.ReadAllText(path));
+
+WriteLine();
+WriteLine("* Deserializing XML files");
+
+using (FileStream xmlLoad = File.Open(path, FileMode.Open))
+{
+  // deserialize and cast the object graph into a List of Person
+  List<Person>? loadedPeople =
+    xs.Deserialize(xmlLoad) as List<Person>;
+
+  if (loadedPeople is not null)
+  {
+    foreach (Person p in loadedPeople)
+    {
+      WriteLine("{0} has {1} children.",
+        p.LastName, p.Children?.Count ?? 0);
+    }
+  }
+}
+
+// create a file to write to
+string jsonPath = Combine(CurrentDirectory, "people.json");
+
+using (StreamWriter jsonStream = File.CreateText(jsonPath))
+{
+  // create an object that will format as JSON
+  Newtonsoft.Json.JsonSerializer jss = new();
+
+  // serialize the object graph into a string
+  jss.Serialize(jsonStream, people);
+}
+
+WriteLine();
+WriteLine("Written {0:N0} bytes of JSON to: {1}",
+  arg0: new FileInfo(jsonPath).Length,
+  arg1: jsonPath);
+
+// Display the serialized object graph
+WriteLine(File.ReadAllText(jsonPath));
+
+WriteLine();
+WriteLine("* Deserializing JSON files");
+
+using (FileStream jsonLoad = File.Open(jsonPath, FileMode.Open))
+{
+  // deserialize object graph into a List of Person
+  List<Person>? loadedPeople =
+    await NewJson.DeserializeAsync(utf8Json: jsonLoad,
+      returnType: typeof(List<Person>)) as List<Person>;
+
+  if (loadedPeople is not null)
+  {
+    foreach (Person p in loadedPeople)
+    {
+      WriteLine("{0} has {1} children.",
+        p.LastName, p.Children?.Count ?? 0);
+    }
+  }
+}

vs4win/Chapter09/WorkingWithSerialization/WorkingWithSerialization.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+	<ItemGroup>
+		<PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
+	</ItemGroup>
+
+</Project>

vs4win/Chapter09/WorkingWithStreams/Program.Compress.cs

@@ -0,0 +1,78 @@
+using System.IO.Compression; // BrotliStream, GZipStream, CompressionMode
+using System.Xml; // XmlWriter, XmlReader
+
+using static System.Environment; // CurrentDirectory
+using static System.IO.Path; // Combine
+
+partial class Program
+{
+  static void Compress(string algorithm = "gzip")
+  {
+    // define a file path using algorithm as file extension
+    string filePath = Combine(
+      CurrentDirectory, $"streams.{algorithm}");
+
+    FileStream file = File.Create(filePath);
+    Stream compressor;
+    if (algorithm == "gzip")
+    {
+      compressor = new GZipStream(file, CompressionMode.Compress);
+    }
+    else
+    {
+      compressor = new BrotliStream(file, CompressionMode.Compress);
+    }
+
+    using (compressor)
+    {
+      using (XmlWriter xml = XmlWriter.Create(compressor))
+      {
+        xml.WriteStartDocument();
+        xml.WriteStartElement("callsigns");
+        foreach (string item in Viper.Callsigns)
+        {
+          xml.WriteElementString("callsign", item);
+        }
+      }
+    } // also closes the underlying stream
+
+    // output all the contents of the compressed file
+    WriteLine("{0} contains {1:N0} bytes.",
+      filePath, new FileInfo(filePath).Length);
+
+    WriteLine($"The compressed contents:");
+    WriteLine(File.ReadAllText(filePath));
+
+    // read a compressed file
+    WriteLine("Reading the compressed XML file:");
+    file = File.Open(filePath, FileMode.Open);
+    Stream decompressor;
+    if (algorithm == "gzip")
+    {
+      decompressor = new GZipStream(
+        file, CompressionMode.Decompress);
+    }
+    else
+    {
+      decompressor = new BrotliStream(
+        file, CompressionMode.Decompress);
+    }
+
+    using (decompressor)
+    {
+      using (XmlReader reader = XmlReader.Create(decompressor))
+      {
+        while (reader.Read())
+        {
+          // check if we are on an element node named callsign
+          if ((reader.NodeType == XmlNodeType.Element)
+            && (reader.Name == "callsign"))
+          {
+            reader.Read(); // move to the text inside element
+            WriteLine($"{reader.Value}"); // read its value
+          }
+        }
+      }
+    }
+  }
+}

vs4win/Chapter09/WorkingWithStreams/Program.Helpers.cs

@@ -0,0 +1,12 @@
+partial class Program
+{
+  static void SectionTitle(string title)
+  {
+    ConsoleColor previousColor = ForegroundColor;
+    ForegroundColor = ConsoleColor.Yellow;
+    WriteLine("*");
+    WriteLine($"* {title}");
+    WriteLine("*");
+    ForegroundColor = previousColor;
+  }
+}

vs4win/Chapter09/WorkingWithStreams/Program.cs

@@ -0,0 +1,94 @@
+using System.Xml;
+
+using static System.Environment;
+using static System.IO.Path;
+
+SectionTitle("Writing to text streams");
+
+// define a file to write to
+string textFile = Combine(CurrentDirectory, "streams.txt");
+
+// create a text file and return a helper writer
+StreamWriter text = File.CreateText(textFile);
+
+// enumerate the strings, writing each one
+// to the stream on a separate line
+foreach (string item in Viper.Callsigns)
+{
+  text.WriteLine(item);
+}
+text.Close(); // release resources
+
+// output the contents of the file
+WriteLine("{0} contains {1:N0} bytes.",
+  arg0: textFile,
+  arg1: new FileInfo(textFile).Length);
+
+WriteLine(File.ReadAllText(textFile));
+
+SectionTitle("Writing to XML streams");
+
+// define a file path to write to
+string xmlFile = Combine(CurrentDirectory, "streams.xml");
+
+// declare variables for the filestream and XML writer
+FileStream? xmlFileStream = null;
+XmlWriter? xml = null;
+
+try
+{
+  // create a file stream
+  xmlFileStream = File.Create(xmlFile);
+
+  // wrap the file stream in an XML writer helper
+  // and automatically indent nested elements
+  xml = XmlWriter.Create(xmlFileStream,
+    new XmlWriterSettings { Indent = true });
+
+  // write the XML declaration
+  xml.WriteStartDocument();
+
+  // write a root element
+  xml.WriteStartElement("callsigns");
+
+  // enumerate the strings writing each one to the stream
+  foreach (string item in Viper.Callsigns)
+  {
+    xml.WriteElementString("callsign", item);
+  }
+
+  // write the close root element
+  xml.WriteEndElement();
+
+  // close helper and stream
+  xml.Close();
+  xmlFileStream.Close();
+}
+catch (Exception ex)
+{
+  // if the path doesn't exist the exception will be caught
+  WriteLine($"{ex.GetType()} says {ex.Message}");
+}
+finally
+{
+  if (xml != null)
+  {
+    xml.Dispose();
+    WriteLine("The XML writer's unmanaged resources have been disposed.");
+    if (xmlFileStream != null)
+    {
+      xmlFileStream.Dispose();
+      WriteLine("The file stream's unmanaged resources have been disposed.");
+    }
+  }
+}
+
+// output all the contents of the file
+WriteLine("{0} contains {1:N0} bytes.",
+  arg0: xmlFile,
+  arg1: new FileInfo(xmlFile).Length);
+WriteLine(File.ReadAllText(xmlFile));
+
+SectionTitle("Compressing streams");
+Compress(algorithm: "gzip");
+Compress(algorithm: "brotli");

vs4win/Chapter09/WorkingWithStreams/Viper.cs

@@ -0,0 +1,9 @@
+static class Viper
+{
+  // define an array of Viper pilot call signs
+  public static string[] Callsigns = new[]
+  {
+    "Husker", "Starbuck", "Apollo", "Boomer",
+    "Bulldog", "Athena", "Helo", "Racetrack"
+  };
+}

vs4win/Chapter09/WorkingWithStreams/WorkingWithStreams.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vscode/Chapter09/Ch09Ex02SerializingShapes/Ch09Ex02SerializingShapes.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vscode/Chapter09/Ch09Ex02SerializingShapes/Circle.cs

@@ -0,0 +1,14 @@
+namespace Packt.Shared;
+
+public class Circle : Shape
+{
+  public override double Area
+  {
+    get
+    {
+      return Math.PI * Radius * Radius;
+    }
+  }
+
+  public double Radius { get; set; }
+}

vscode/Chapter09/Ch09Ex02SerializingShapes/Program.cs

@@ -0,0 +1,50 @@
+using Packt.Shared; // Circle, Rectangle, Shape
+using System.Xml.Serialization; // XmlSerializer
+
+using static System.Environment;
+using static System.IO.Path;
+
+// create a file path to write to
+string path = Combine(CurrentDirectory, "shapes.xml");
+
+// create a list of Shape objects to serialize
+List<Shape> listOfShapes = new()
+{
+  new Circle { Colour = "Red", Radius = 2.5 },
+  new Rectangle { Colour = "Blue", Height = 20.0, Width = 10.0 },
+  new Circle { Colour = "Green", Radius = 8 },
+  new Circle { Colour = "Purple", Radius = 12.3 },
+  new Rectangle { Colour = "Blue", Height = 45.0, Width = 18.0 }
+};
+
+// create an object that knows how to serialize and deserialize 
+// a list of Shape objects
+XmlSerializer serializerXml = new(listOfShapes.GetType());
+
+WriteLine("Saving shapes to XML file:");
+
+using (FileStream fileXml = File.Create(path))
+{
+  serializerXml.Serialize(fileXml, listOfShapes);
+}
+
+WriteLine("Loading shapes from XML file:");
+List<Shape>? loadedShapesXml = null;
+
+using (FileStream fileXml = File.Open(path, FileMode.Open))
+{
+  loadedShapesXml =
+    serializerXml.Deserialize(fileXml) as List<Shape>;
+}
+
+if (loadedShapesXml == null)
+{
+  WriteLine($"{nameof(loadedShapesXml)} is empty.");
+}
+else
+{
+  foreach (Shape item in loadedShapesXml)
+  {
+    WriteLine($"{item.GetType().Name} is {item.Colour} and has an area of {item.Area:N2}");
+  }
+}

vscode/Chapter09/Ch09Ex02SerializingShapes/Rectangle.cs

@@ -0,0 +1,15 @@
+namespace Packt.Shared;
+
+public class Rectangle : Shape
+{
+  public override double Area
+  {
+    get
+    {
+      return Height * Width;
+    }
+  }
+
+  public double Height { get; set; }
+  public double Width { get; set; }
+}

vscode/Chapter09/Ch09Ex02SerializingShapes/Shape.cs

@@ -0,0 +1,11 @@
+using System.Xml.Serialization;
+
+namespace Packt.Shared;
+
+[XmlInclude(typeof(Circle))]
+[XmlInclude(typeof(Rectangle))]
+public abstract class Shape
+{
+  public string? Colour { get; set; }
+  public abstract double Area { get; }
+}

vscode/Chapter09/Chapter09.code-workspace

@@ -0,0 +1,22 @@
+{
+	"folders": [
+		{
+			"path": "WorkingWithFileSystems"
+		},
+		{
+			"path": "WorkingWithStreams"
+		},
+		{
+			"path": "WorkingWithEncodings"
+		},
+		{
+			"path": "WorkingWithSerialization"
+		},
+		{
+			"path": "WorkingWithJson"
+		},
+		{
+			"path": "Ch09Ex02SerializingShapes"
+		}
+	]
+}

vscode/Chapter09/WorkingWithEncodings/Program.cs

@@ -0,0 +1,51 @@
+using Packt.Shared;
+using System.Text;
+
+WriteLine("Encodings");
+WriteLine("[1] ASCII");
+WriteLine("[2] UTF-7");
+WriteLine("[3] UTF-8");
+WriteLine("[4] UTF-16 (Unicode)");
+WriteLine("[5] UTF-32");
+WriteLine("[6] Latin1");
+WriteLine("[any other key] Default encoding");
+WriteLine();
+
+// choose an encoding
+Write("Press a number to choose an encoding.");
+ConsoleKey number = ReadKey(intercept: true).Key;
+WriteLine(); WriteLine();
+
+Encoding encoder = number switch
+{
+  ConsoleKey.D1 or ConsoleKey.NumPad1 => Encoding.ASCII,
+  ConsoleKey.D2 or ConsoleKey.NumPad2 => Encoding.UTF7,
+  ConsoleKey.D3 or ConsoleKey.NumPad3 => Encoding.UTF8,
+  ConsoleKey.D4 or ConsoleKey.NumPad4 => Encoding.Unicode,
+  ConsoleKey.D5 or ConsoleKey.NumPad5 => Encoding.UTF32,
+  ConsoleKey.D6 or ConsoleKey.NumPad6 => Encoding.Latin1,
+  _                                   => Encoding.Default
+};
+
+// define a string to encode
+string message = "Café £4.39";
+WriteLine($"Text to encode: {message}  Characters: {message.Length}");
+
+// encode the string into a byte array
+byte[] encoded = encoder.GetBytes(message);
+
+// check how many bytes the encoding needed
+WriteLine("{0} used {1:N0} bytes.",
+  encoder.GetType().Name, encoded.Length);
+WriteLine();
+
+// enumerate each byte 
+WriteLine($"BYTE | HEX | CHAR");
+foreach (byte b in encoded)
+{
+  WriteLine($"{b,4} | {b.ToString("X"),3} | {(char)b,4}");
+}
+
+// decode the byte array back into a string and display it
+string decoded = encoder.GetString(encoded);
+WriteLine(decoded);

vscode/Chapter09/WorkingWithEncodings/WorkingWithEncodings.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vscode/Chapter09/WorkingWithFileSystems/Program.Helpers.cs

@@ -0,0 +1,12 @@
+partial class Program
+{
+  static void SectionTitle(string title)
+  {
+    ConsoleColor previousColor = ForegroundColor;
+    ForegroundColor = ConsoleColor.Yellow;
+    WriteLine("*");
+    WriteLine($"* {title}");
+    WriteLine("*");
+    ForegroundColor = previousColor;
+  }
+}

vscode/Chapter09/WorkingWithFileSystems/Program.cs

@@ -0,0 +1,132 @@
+using static System.IO.Directory;
+using static System.IO.Path;
+using static System.Environment;
+
+SectionTitle("Handling cross-platform environments and filesystems");
+
+WriteLine("{0,-33} {1}", arg0: "Path.PathSeparator",
+  arg1: PathSeparator);
+WriteLine("{0,-33} {1}", arg0: "Path.DirectorySeparatorChar",
+  arg1: DirectorySeparatorChar);
+WriteLine("{0,-33} {1}", arg0: "Directory.GetCurrentDirectory()",
+  arg1: GetCurrentDirectory());
+WriteLine("{0,-33} {1}", arg0: "Environment.CurrentDirectory",
+  arg1: CurrentDirectory);
+WriteLine("{0,-33} {1}", arg0: "Environment.SystemDirectory",
+  arg1: SystemDirectory);
+WriteLine("{0,-33} {1}", arg0: "Path.GetTempPath()",
+  arg1: GetTempPath());
+WriteLine("GetFolderPath(SpecialFolder");
+WriteLine("{0,-33} {1}", arg0: " .System)",
+  arg1: GetFolderPath(SpecialFolder.System));
+WriteLine("{0,-33} {1}", arg0: " .ApplicationData)",
+  arg1: GetFolderPath(SpecialFolder.ApplicationData));
+WriteLine("{0,-33} {1}", arg0: " .MyDocuments)",
+  arg1: GetFolderPath(SpecialFolder.MyDocuments));
+WriteLine("{0,-33} {1}", arg0: " .Personal)",
+  arg1: GetFolderPath(SpecialFolder.Personal));
+
+SectionTitle("Managing drives");
+
+WriteLine("{0,-30} | {1,-10} | {2,-7} | {3,18} | {4,18}",
+  "NAME", "TYPE", "FORMAT", "SIZE (BYTES)", "FREE SPACE");
+
+foreach (DriveInfo drive in DriveInfo.GetDrives())
+{
+  if (drive.IsReady)
+  {
+    WriteLine(
+      "{0,-30} | {1,-10} | {2,-7} | {3,18:N0} | {4,18:N0}",
+      drive.Name, drive.DriveType, drive.DriveFormat,
+      drive.TotalSize, drive.AvailableFreeSpace);
+  }
+  else
+  {
+    WriteLine("{0,-30} | {1,-10}", drive.Name, drive.DriveType);
+  }
+}
+
+SectionTitle("Managing directories");
+
+// define a directory path for a new folder
+// starting in the user's folder
+string newFolder = Combine(
+  GetFolderPath(SpecialFolder.Personal), "NewFolder");
+
+WriteLine($"Working with: {newFolder}");
+
+// check if it exists
+WriteLine($"Does it exist? {Exists(newFolder)}");
+
+// create directory 
+WriteLine("Creating it...");
+CreateDirectory(newFolder);
+WriteLine($"Does it exist? {Exists(newFolder)}");
+Write("Confirm the directory exists, and then press ENTER: ");
+ReadLine();
+
+// delete directory 
+WriteLine("Deleting it...");
+Delete(newFolder, recursive: true);
+WriteLine($"Does it exist? {Exists(newFolder)}");
+
+SectionTitle("Managing files");
+
+// define a directory path to output files
+// starting in the user's folder
+string dir = Combine(
+  GetFolderPath(SpecialFolder.Personal), "OutputFiles");
+
+CreateDirectory(dir);
+
+// define file paths
+string textFile = Combine(dir, "Dummy.txt");
+string backupFile = Combine(dir, "Dummy.bak");
+WriteLine($"Working with: {textFile}");
+
+// check if a file exists
+WriteLine($"Does it exist? {File.Exists(textFile)}");
+
+// create a new text file and write a line to it
+StreamWriter textWriter = File.CreateText(textFile);
+textWriter.WriteLine("Hello, C#!");
+textWriter.Close(); // close file and release resources
+WriteLine($"Does it exist? {File.Exists(textFile)}");
+
+// copy the file, and overwrite if it already exists
+File.Copy(sourceFileName: textFile,
+  destFileName: backupFile, overwrite: true);
+
+WriteLine(
+  $"Does {backupFile} exist? {File.Exists(backupFile)}");
+
+Write("Confirm the files exist, and then press ENTER: ");
+ReadLine();
+
+// delete file
+File.Delete(textFile);
+WriteLine($"Does it exist? {File.Exists(textFile)}");
+
+// read from the text file backup
+WriteLine($"Reading contents of {backupFile}:");
+StreamReader textReader = File.OpenText(backupFile);
+WriteLine(textReader.ReadToEnd());
+textReader.Close();
+
+SectionTitle("Managing paths");
+
+WriteLine($"Folder Name: {GetDirectoryName(textFile)}");
+WriteLine($"File Name: {GetFileName(textFile)}");
+WriteLine("File Name without Extension: {0}",
+  GetFileNameWithoutExtension(textFile));
+WriteLine($"File Extension: {GetExtension(textFile)}");
+WriteLine($"Random File Name: {GetRandomFileName()}");
+WriteLine($"Temporary File Name: {GetTempFileName()}");
+
+SectionTitle("Getting file information ");
+
+FileInfo info = new(backupFile);
+WriteLine($"{backupFile}:");
+WriteLine($"Contains {info.Length} bytes");
+WriteLine($"Last accessed {info.LastAccessTime}");
+WriteLine($"Has readonly set to {info.IsReadOnly}");

vscode/Chapter09/WorkingWithFileSystems/WorkingWithFileSystems.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vscode/Chapter09/WorkingWithJson/Book.cs

@@ -0,0 +1,23 @@
+using System.Text.Json.Serialization; // [JsonInclude]
+
+public class Book
+{
+  // constructor to set non-nullable property
+  public Book(string title)
+  {
+    Title = title;
+  }
+
+  // properties
+  public string Title { get; set; }
+  public string? Author { get; set; }
+
+  // fields
+  [JsonInclude] // include this field
+  public DateTime PublishDate;
+
+  [JsonInclude] // include this field
+  public DateTimeOffset Created;
+
+  public ushort Pages;
+}

vscode/Chapter09/WorkingWithJson/Program.cs

@@ -0,0 +1,39 @@
+using System.Text.Json; // JsonSerializer
+
+using static System.Environment;
+using static System.IO.Path;
+
+Book mybook = new(title:
+  "C# 11 and .NET 7 - Modern Cross-platform Development")
+{
+  Author = "Mark J Price",
+  PublishDate = new(year: 2022, month: 11, day: 8),
+  Pages = 823,
+  Created = DateTimeOffset.UtcNow,
+};
+
+JsonSerializerOptions options = new()
+{
+  /*
+  IncludeFields = true, // includes all fields
+  PropertyNameCaseInsensitive = true,
+  WriteIndented = true,
+  PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+  */
+};
+
+string filePath = Combine(CurrentDirectory, "mybook.json");
+
+using (Stream fileStream = File.Create(filePath))
+{
+  JsonSerializer.Serialize<Book>(
+    utf8Json: fileStream, value: mybook, options);
+}
+
+WriteLine("Written {0:N0} bytes of JSON to {1}",
+  arg0: new FileInfo(filePath).Length,
+  arg1: filePath);
+WriteLine();
+
+// Display the serialized object graph 
+WriteLine(File.ReadAllText(filePath));

vscode/Chapter09/WorkingWithJson/WorkingWithJson.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>

vscode/Chapter09/WorkingWithSerialization/Person.cs

@@ -0,0 +1,26 @@
+using System.Xml.Serialization; // [XmlAttribute]
+
+namespace Packt.Shared;
+
+public class Person
+{
+  public Person() { }
+
+  public Person(decimal initialSalary)
+  {
+    Salary = initialSalary;
+  }
+
+  [XmlAttribute("fname")]
+  public string? FirstName { get; set; }
+
+  [XmlAttribute("lname")]
+  public string? LastName { get; set; }
+
+  [XmlAttribute("dob")]
+  public DateTime DateOfBirth { get; set; }
+
+  public HashSet<Person>? Children { get; set; }
+
+  protected decimal Salary { get; set; }
+}

vscode/Chapter09/WorkingWithSerialization/Program.cs

@@ -0,0 +1,117 @@
+using System.Xml.Serialization; // XmlSerializer
+using Packt.Shared; // Person 
+using NewJson = System.Text.Json.JsonSerializer;
+
+using static System.Environment;
+using static System.IO.Path;
+
+// create an object graph
+List<Person> people = new()
+{
+  new(30000M)
+  {
+    FirstName = "Alice",
+    LastName = "Smith",
+    DateOfBirth = new(year: 1974, month: 3, day: 14)
+  },
+  new(40000M)
+  {
+    FirstName = "Bob",
+    LastName = "Jones",
+    DateOfBirth = new(year: 1969, month: 11, day: 23)
+  },
+  new(20000M)
+  {
+    FirstName = "Charlie",
+    LastName = "Cox",
+    DateOfBirth = new(year: 1984, month: 5, day: 4),
+    Children = new()
+    {
+      new(0M)
+      {
+        FirstName = "Sally",
+        LastName = "Cox",
+        DateOfBirth = new(year: 2012, month: 7, day: 12)
+      }
+    }
+  }
+};
+
+// create object that will format a List of Persons as XML
+XmlSerializer xs = new(type: people.GetType());
+
+// create a file to write to
+string path = Combine(CurrentDirectory, "people.xml");
+
+using (FileStream stream = File.Create(path))
+{
+  // serialize the object graph to the stream
+  xs.Serialize(stream, people);
+}
+
+WriteLine("Written {0:N0} bytes of XML to {1}",
+  arg0: new FileInfo(path).Length,
+  arg1: path);
+WriteLine();
+
+// Display the serialized object graph
+WriteLine(File.ReadAllText(path));
+
+WriteLine();
+WriteLine("* Deserializing XML files");
+
+using (FileStream xmlLoad = File.Open(path, FileMode.Open))
+{
+  // deserialize and cast the object graph into a List of Person
+  List<Person>? loadedPeople =
+    xs.Deserialize(xmlLoad) as List<Person>;
+
+  if (loadedPeople is not null)
+  {
+    foreach (Person p in loadedPeople)
+    {
+      WriteLine("{0} has {1} children.",
+        p.LastName, p.Children?.Count ?? 0);
+    }
+  }
+}
+
+// create a file to write to
+string jsonPath = Combine(CurrentDirectory, "people.json");
+
+using (StreamWriter jsonStream = File.CreateText(jsonPath))
+{
+  // create an object that will format as JSON
+  Newtonsoft.Json.JsonSerializer jss = new();
+
+  // serialize the object graph into a string
+  jss.Serialize(jsonStream, people);
+}
+
+WriteLine();
+WriteLine("Written {0:N0} bytes of JSON to: {1}",
+  arg0: new FileInfo(jsonPath).Length,
+  arg1: jsonPath);
+
+// Display the serialized object graph
+WriteLine(File.ReadAllText(jsonPath));
+
+WriteLine();
+WriteLine("* Deserializing JSON files");
+
+using (FileStream jsonLoad = File.Open(jsonPath, FileMode.Open))
+{
+  // deserialize object graph into a List of Person
+  List<Person>? loadedPeople =
+    await NewJson.DeserializeAsync(utf8Json: jsonLoad,
+      returnType: typeof(List<Person>)) as List<Person>;
+
+  if (loadedPeople is not null)
+  {
+    foreach (Person p in loadedPeople)
+    {
+      WriteLine("{0} has {1} children.",
+        p.LastName, p.Children?.Count ?? 0);
+    }
+  }
+}

vscode/Chapter09/WorkingWithSerialization/WorkingWithSerialization.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+	<ItemGroup>
+		<PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
+	</ItemGroup>
+
+</Project>

vscode/Chapter09/WorkingWithStreams/Program.Compress.cs

@@ -0,0 +1,78 @@
+using System.IO.Compression; // BrotliStream, GZipStream, CompressionMode
+using System.Xml; // XmlWriter, XmlReader
+
+using static System.Environment; // CurrentDirectory
+using static System.IO.Path; // Combine
+
+partial class Program
+{
+  static void Compress(string algorithm = "gzip")
+  {
+    // define a file path using algorithm as file extension
+    string filePath = Combine(
+      CurrentDirectory, $"streams.{algorithm}");
+
+    FileStream file = File.Create(filePath);
+    Stream compressor;
+    if (algorithm == "gzip")
+    {
+      compressor = new GZipStream(file, CompressionMode.Compress);
+    }
+    else
+    {
+      compressor = new BrotliStream(file, CompressionMode.Compress);
+    }
+
+    using (compressor)
+    {
+      using (XmlWriter xml = XmlWriter.Create(compressor))
+      {
+        xml.WriteStartDocument();
+        xml.WriteStartElement("callsigns");
+        foreach (string item in Viper.Callsigns)
+        {
+          xml.WriteElementString("callsign", item);
+        }
+      }
+    } // also closes the underlying stream
+
+    // output all the contents of the compressed file
+    WriteLine("{0} contains {1:N0} bytes.",
+      filePath, new FileInfo(filePath).Length);
+
+    WriteLine($"The compressed contents:");
+    WriteLine(File.ReadAllText(filePath));
+
+    // read a compressed file
+    WriteLine("Reading the compressed XML file:");
+    file = File.Open(filePath, FileMode.Open);
+    Stream decompressor;
+    if (algorithm == "gzip")
+    {
+      decompressor = new GZipStream(
+        file, CompressionMode.Decompress);
+    }
+    else
+    {
+      decompressor = new BrotliStream(
+        file, CompressionMode.Decompress);
+    }
+
+    using (decompressor)
+    {
+      using (XmlReader reader = XmlReader.Create(decompressor))
+      {
+        while (reader.Read())
+        {
+          // check if we are on an element node named callsign
+          if ((reader.NodeType == XmlNodeType.Element)
+            && (reader.Name == "callsign"))
+          {
+            reader.Read(); // move to the text inside element
+            WriteLine($"{reader.Value}"); // read its value
+          }
+        }
+      }
+    }
+  }
+}

vscode/Chapter09/WorkingWithStreams/Program.Helpers.cs

@@ -0,0 +1,12 @@
+partial class Program
+{
+  static void SectionTitle(string title)
+  {
+    ConsoleColor previousColor = ForegroundColor;
+    ForegroundColor = ConsoleColor.Yellow;
+    WriteLine("*");
+    WriteLine($"* {title}");
+    WriteLine("*");
+    ForegroundColor = previousColor;
+  }
+}

vscode/Chapter09/WorkingWithStreams/Program.cs

@@ -0,0 +1,94 @@
+using System.Xml;
+
+using static System.Environment;
+using static System.IO.Path;
+
+SectionTitle("Writing to text streams");
+
+// define a file to write to
+string textFile = Combine(CurrentDirectory, "streams.txt");
+
+// create a text file and return a helper writer
+StreamWriter text = File.CreateText(textFile);
+
+// enumerate the strings, writing each one
+// to the stream on a separate line
+foreach (string item in Viper.Callsigns)
+{
+  text.WriteLine(item);
+}
+text.Close(); // release resources
+
+// output the contents of the file
+WriteLine("{0} contains {1:N0} bytes.",
+  arg0: textFile,
+  arg1: new FileInfo(textFile).Length);
+
+WriteLine(File.ReadAllText(textFile));
+
+SectionTitle("Writing to XML streams");
+
+// define a file path to write to
+string xmlFile = Combine(CurrentDirectory, "streams.xml");
+
+// declare variables for the filestream and XML writer
+FileStream? xmlFileStream = null;
+XmlWriter? xml = null;
+
+try
+{
+  // create a file stream
+  xmlFileStream = File.Create(xmlFile);
+
+  // wrap the file stream in an XML writer helper
+  // and automatically indent nested elements
+  xml = XmlWriter.Create(xmlFileStream,
+    new XmlWriterSettings { Indent = true });
+
+  // write the XML declaration
+  xml.WriteStartDocument();
+
+  // write a root element
+  xml.WriteStartElement("callsigns");
+
+  // enumerate the strings writing each one to the stream
+  foreach (string item in Viper.Callsigns)
+  {
+    xml.WriteElementString("callsign", item);
+  }
+
+  // write the close root element
+  xml.WriteEndElement();
+
+  // close helper and stream
+  xml.Close();
+  xmlFileStream.Close();
+}
+catch (Exception ex)
+{
+  // if the path doesn't exist the exception will be caught
+  WriteLine($"{ex.GetType()} says {ex.Message}");
+}
+finally
+{
+  if (xml != null)
+  {
+    xml.Dispose();
+    WriteLine("The XML writer's unmanaged resources have been disposed.");
+    if (xmlFileStream != null)
+    {
+      xmlFileStream.Dispose();
+      WriteLine("The file stream's unmanaged resources have been disposed.");
+    }
+  }
+}
+
+// output all the contents of the file
+WriteLine("{0} contains {1:N0} bytes.",
+  arg0: xmlFile,
+  arg1: new FileInfo(xmlFile).Length);
+WriteLine(File.ReadAllText(xmlFile));
+
+SectionTitle("Compressing streams");
+Compress(algorithm: "gzip");
+Compress(algorithm: "brotli");

vscode/Chapter09/WorkingWithStreams/Viper.cs

@@ -0,0 +1,9 @@
+static class Viper
+{
+  // define an array of Viper pilot call signs
+  public static string[] Callsigns = new[]
+  {
+    "Husker", "Starbuck", "Apollo", "Boomer",
+    "Bulldog", "Athena", "Helo", "Racetrack"
+  };
+}

vscode/Chapter09/WorkingWithStreams/WorkingWithStreams.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<Using Include="System.Console" Static="true" />
+	</ItemGroup>
+
+</Project>