UWP从在不同线程中运行的任务更新UI控件

Question

UI has a label named lblMyLabel. It's bound to a view model MyViewModel.

A task is running on a different thread which pulls message from a service.( for example)

When a this task receives a specific value it should update the UI label with it.

I always get a error that it was Marshalled in a different thread .

Answer 1

When you want to update UI,you should run on the UI's dispatcher thread.You can call Dispatcher.RunAsync to back onto the UI's dispatcher thread.

private void Button_Click(object sender, RoutedEventArgs e)
{
    //Start a Task
    Task t = Task.Factory.StartNew(() => {
        int i = 0;
        for (i = 0; i <= 1000; i++)
        { 
        }
        //Back onto the UI thread
        var a = Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
        {
            //Update UI
            MyTextBlock.Text = "Update";
        });
    });
}