Initial commit

vs4win/Chapter09/WorkingWithStreams/Program.Compress.cs

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+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

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+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

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+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

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+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

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+<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>