Cannot convert anonymous method to type 'System.Delegate' because it is not a delegate type
c#, wpf
Solution
Anonymous functions (lambda expressions and anonymous methods) have to be converted to a specific delegate type, whereas `Dispatcher.BeginInvoke` just takes `Delegate`. There are two options for this...
Still use the existing `BeginInvoke` call, but specify the delegate type. There are various approaches here, but I generally extract the anonymous function to a previous statement:
Action action = delegate() {
this.Log.Add(...);
};
Dispatcher.BeginInvoke(action);
Write an extension method on `Dispatcher` which takes `Action` instead of `Delegate`:
public static void BeginInvokeAction(this Dispatcher dispatcher,
Action action)
{
Dispatcher.BeginInvoke(action);
}
Then you can call the extension method with the implicit conversion
this.Dispatcher.BeginInvokeAction(
delegate()
{
this.Log.Add(...);
});
I'd also encourage you to use lambda expressions instead of anonymous methods, in general:
Dispatcher.BeginInvokeAction(() => this.Log.Add(...));
EDIT: As noted in comments, `Dispatcher.BeginInvoke` gained an overload in .NET 4.5 which takes an `Action` directly, so you don't need the extension method in that case.
Problem
I want to execute this code on the main thread in the WPF app and getting an error I can't figure out what is wrong: ``` private void AddLog(string logItem) { this.Dispatcher.BeginInvoke( delegate() { this.Log.Add(new KeyValuePair<string, string>(DateTime.Now.ToLongTimeString(), logItem)); }); } ```