Question

I know how to do a thread safe update on a text box that was already defined http://msdn.microsoft.com/en-us/library/ms171728.aspx …. how can i do this on text boxes that were generated later on in the program? You advice is much appreciated.

Answer 1

Given some TextBox object, just invoke on it:

TextBox foo = new TextBox(...);

// Code to add the new box to the form has been omitted; presumably
// you do this already.

Action update = delegate { foo.Text = "Changed!"; };

if (foo.InvokeRequired) {
    foo.Invoke(update);
} else {
    update();
}

If you’re using this pattern a lot, this extension method might be helpful:

public static void AutoInvoke(
    this System.ComponentModel.ISynchronizeInvoke self,
    Action action)
{
    if (self == null) throw new ArgumentNullException("self");
    if (action == null) throw new ArgumentNullException("action");

    if (self.InvokeRequired) {
        self.Invoke(action);
    } else {
        action();
    }
}

Then you can reduce your code to:

foo.AutoInvoke(() => foo.Text = "Changed!");

This will just do the right thing, executing the delegate on the main GUI thread whether or not you are currently executing on it.