如何从另一个线程的静态方法更改文本框的文本？

Question

I have got problems to combine two tasks: Dispatcher.Invoke and create an object instance.

I have got a textbox:

<TextBox x:Name="txtuid">

Here is the static method:

static private int onCallback(string Arr, int Len)
{
     MainWindow my = new MainWindow();
     my.txtuid.Text = Arr;
     ....
     return 0;
}

The problem is, that onCallback is running in another Thread and I have to use Dispatcher.Invoke for MainWindow my = new MainWindow() , but how can I do this?

Answer 1

In this scenario when you're about to instantiate a new Control rather than modify already existing one the easiest solution is to use Application.Current.Dispatcher :

static private int onCallback(string Arr, int Len)
{
    Application.Current.Dispatcher.Invoke(new Action(() =>
    {
        MainWindow my = new MainWindow();
        my.txtuid.Text = Arr;
        ....
    }));
    return 0;
}

Answer 2

You should to set the Text property of the existing instance of the MainWindow instead of creating a new one:

static private int onCallback(string Arr, int Len)
{
    Application.Current.Dispatcher.Invoke(new Action(() =>
    {
        MainWindow my = Application.Current.Windows.OfType<MainWindow>().FirstOrDefault();
        my.txtuid.Text = Arr;
    }));
    return 0;
}