diff --git a/csharp.html.markdown b/csharp.html.markdown
index 442700a6..cca99fb0 100644
--- a/csharp.html.markdown
+++ b/csharp.html.markdown
@@ -1006,15 +1006,101 @@ on a new line! ""Wow!"", the masses cried";
// x?.y will return null immediately if x is null; y is not evaluated
=> GenieName?.ToUpper();
}
+
+ static class MagicService
+ {
+ private static bool LogException(Exception ex)
+ {
+ /* log exception somewhere */
+ return false;
+ }
+
+ public static bool CastSpell(string spell)
+ {
+ try
+ {
+ // Pretend we call API here
+ throw new MagicServiceException("Spell failed", 42);
+
+ // Spell succeeded
+ return true;
+ }
+ // Only catch if Code is 42 i.e. spell failed
+ catch(MagicServiceException ex) when (ex.Code == 42)
+ {
+ // Spell failed
+ return false;
+ }
+ // Other exceptions, or MagicServiceException where Code is not 42
+ catch(Exception ex) when (LogException(ex))
+ {
+ // Execution never reaches this block
+ // The stack is not unwound
+ }
+ return false;
+ // Note that catching a MagicServiceException and rethrowing if Code
+ // is not 42 or 117 is different, as then the final catch-all block
+ // will not catch the rethrown exception
+ }
+ }
+
+ public class MagicServiceException : Exception
+ {
+ public int Code { get; }
+
+ public MagicServiceException(string message, int code) : base(message)
+ {
+ Code = code;
+ }
+ }
+
+ public static class PragmaWarning {
+ // Obsolete attribute
+ [Obsolete("Use NewMethod instead", false)]
+ public static void ObsoleteMethod()
+ {
+ /* obsolete code */
+ }
+
+ public static void NewMethod()
+ {
+ /* new code */
+ }
+
+ public static void Main()
+ {
+ ObsoleteMethod(); // CS0618: 'ObsoleteMethod is obsolete: Use NewMethod instead'
+#pragma warning disable CS0618
+ ObsoleteMethod(); // no warning
+#pragma warning restore CS0618
+ ObsoleteMethod(); // CS0618: 'ObsoleteMethod is obsolete: Use NewMethod instead'
+ }
+ }
} // End Namespace
+
+using System;
+// C# 6, static using
+using static System.Math;
+
+namespace Learning.More.CSharp
+{
+ class StaticUsing
+ {
+ static void Main()
+ {
+ // Without a static using statement..
+ Console.WriteLine("The square root of 4 is {}.", Math.Sqrt(4));
+ // With one
+ Console.WriteLine("The square root of 4 is {}.", Sqrt(4));
+ }
+ }
+}
```
## Topics Not Covered
* Attributes
- * async/await, pragma directives
- * Exception filters
- * `using static`
+ * async/await
* Web Development
* ASP.NET MVC & WebApi (new)
* ASP.NET Web Forms (old)