Question

I’m using a Dispatcher to update my UI before I handle some resiszing.
The Problem ist the part of BeginInvoke(DispatcherPriorty, new ACTION) is where I am stuck.
I want to call a method with Parameters and I don”t know why.

Thats my current Dispatcher:

void s_SizeChanged(object sender, SizeChangedEventArgs e)
{
    Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, new Action(test));

}

And this is my method i am calling:

public void test()
{
    foreach (Structures s in ((TreeView)this.cont.Children[0]).Items)
        s.updateRelationLines(this.Data, this.cont.ColumnDefinitions[1]);
}

I just want to replace this.Data and this.cont.Columndefinitions[1] with Parameters.

Answer 1

You can use a lambda expression for this:

Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, 
    new Action(() => test(param1, param2)));

This basically creates an anonymous method

void myMethod() {
    test(param1, param2);
}

and invokes this method through the dispatcher. Some compiler magic ensures that param1 and param2 are available to this method, even if they are only in the scope of your s_SizeChanged method. More details on this can be found here:

• Lambda Expressions (C# Programming Guide)