--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MetroWpf/MetroWpf.Xaml/Binding/BindingErrorTraceListener.cs	Mon Mar 12 23:05:21 2012 +0800
@@ -0,0 +1,69 @@
+// http://www.switchonthecode.com/tutorials/wpf-snippet-detecting-binding-errors
+
+using System.Diagnostics;
+using System.Text;
+using System.Windows;
+
+namespace MetroWpf.Xaml.Binding
+{
+  public class BindingErrorTraceListener : DefaultTraceListener
+  {
+    private static BindingErrorTraceListener _listener;
+
+
+    private readonly StringBuilder _message = new StringBuilder();
+
+    private BindingErrorTraceListener()
+    {
+    }
+
+    public override void Write(string message)
+    {
+      _message.Append(message);
+    }
+
+    public override void WriteLine(string message)
+    {
+      _message.Append(message);
+
+      var final = _message.ToString();
+      _message.Length = 0;
+
+      MessageBox.Show(final, 
+        "Binding Error", 
+        MessageBoxButton.OK,
+        MessageBoxImage.Error);
+    }
+
+    public static void CloseTrace()
+    {
+      if (_listener == null)
+      {
+        return;
+      }
+
+      _listener.Flush();
+      _listener.Close();
+      PresentationTraceSources.DataBindingSource.Listeners.Remove(_listener);
+      _listener = null;
+    }
+
+    [Conditional("DEBUG")]
+    public static void SetTrace()
+    {
+      SetTrace(SourceLevels.Error, TraceOptions.None);
+    }
+
+    public static void SetTrace(SourceLevels level, TraceOptions options)
+    {
+      if (_listener == null)
+      {
+        _listener = new BindingErrorTraceListener();
+        PresentationTraceSources.DataBindingSource.Listeners.Add(_listener);
+      }
+
+      _listener.TraceOutputOptions = options;
+      PresentationTraceSources.DataBindingSource.Switch.Level = level;
+    }
+  }
+}