Initial commit

vscode/Chapter04/Instrumenting/Program.cs

@@ -0,0 +1,43 @@
+using System.Diagnostics;
+using Microsoft.Extensions.Configuration;
+
+string logPath = Path.Combine(Environment.GetFolderPath(
+    Environment.SpecialFolder.DesktopDirectory), "log.txt");
+
+Console.WriteLine($"Writing to: {logPath}");
+
+TextWriterTraceListener logFile = new(File.CreateText(logPath));
+
+Trace.Listeners.Add(logFile);
+
+// text writer is buffered, so this option calls
+// Flush() on all listeners after writing
+Trace.AutoFlush = true;
+
+Debug.WriteLine("Debug says, I am watching!");
+Trace.WriteLine("Trace says, I am watching!");
+
+Console.WriteLine("Reading from appsettings.json in {0}",
+  arg0: Directory.GetCurrentDirectory());
+
+ConfigurationBuilder builder = new();
+
+builder.SetBasePath(Directory.GetCurrentDirectory());
+
+builder.AddJsonFile("appsettings.json",
+  optional: false, reloadOnChange: true);
+
+IConfigurationRoot configuration = builder.Build();
+
+TraceSwitch ts = new(
+  displayName: "PacktSwitch",
+  description: "This switch is set via a JSON config.");
+
+configuration.GetSection("PacktSwitch").Bind(ts);
+
+Trace.WriteLineIf(ts.TraceError, "Trace error");
+Trace.WriteLineIf(ts.TraceWarning, "Trace warning");
+Trace.WriteLineIf(ts.TraceInfo, "Trace information");
+Trace.WriteLineIf(ts.TraceVerbose, "Trace verbose");
+
+Console.ReadLine();