Differences

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--- swdev:dotnet:actions [2011/01/26 16:11]
smayr [Using Actions to Communicate Between Background Worker and Main Threads]
+++ swdev:dotnet:actions [2011/01/26 16:55] (current)
smayr [Example]
@@ Line 13: / Line 13: @@
 <code csharp>
-using System.Windows.Threading;
+using System.Windows.Threading;  // in WindowsBase.dll
 public partial class MyWindow : Window
@@ Line 40: / Line 40: @@
   * [[http://www.albahari.com/threading/part2.aspx#_Rich_Client_Applications|Threading (Part 2): Rich Client Applications and Thread Affinity]]
+== Example ==
+<code csharp>
+///----------------------------------------------------------------------------------------
+/// <summary>
+/// Close the popup menu.
+/// </summary>
+///----------------------------------------------------------------------------------------
+public void Close()
+{
+    //----------------------------------------------------------------------------
+    // Deal with cross thread ownership of UI control instance
+    // by invoking an action delegate. In other words,
+    // popupmnu is owned by thread that instantiated it (when Open() was called),
+    // so we cannot close popmnu arbitrarily.  We need the help of
+    // the owner thread's Dispatcher to execute the Close() for us.
+    //----------------------------------------------------------------------------
+    //Action action = () => popmnuReports.IsOpen = false;
+    Action action = this.CloseDelegate();
+    this.Dispatcher.BeginInvoke(action);
+}
+///----------------------------------------------------------------------------------------
+/// <summary>
+/// Close method deletegate, used by cross thread dispatcher.
+/// </summary>
+/// <returns></returns>
+///----------------------------------------------------------------------------------------
+private Action CloseDelegate()
+{
+    return delegate()
+    {
+        popmnuFitting.IsOpen = false;
+        m_TimerForDisplay.Enabled = false;
+    };
+}
+</code>
 == Resources ==
   * [[http://dotnetperls.com/action|DotNetPerls: Action]]