Mouse.LeftButton == MouseButtonState.Pressed never returning true

Question

I have a Windows Forms Application in C# which monitors if the mouse buttons are being held down. There is a primary thread for the GUI, which spawns a secondary STA thread. This code never executes within it:

 if (Mouse.LeftButton == MouseButtonState.Pressed)
 {
    System.Diagnostics.Debug.WriteLine("Left mouse down");
 }

I wondered if this is because I have the following STA option enabled for the thread?

 repeaterThread.SetApartmentState(ApartmentState.STA);
 repeaterThread.Start();

Full relevant code: I'm using PresentationCore.dll, and System.Windows.Input; Winforms GUI:

On start button pressed:

 ...
 Thread repeaterThread = new Thread(() => ListenerThread());
 repeaterThread.SetApartmentState(ApartmentState.STA);
 repeaterThread.Start();
 ...

ListenerThread method:

public static void ListenerThread()
{
   while(true)
   {
      if (Mouse.LeftButton == MouseButtonState.Pressed)
      {
         System.Diagnostics.Debug.WriteLine("Left mouse down");
      }
      Thread.sleep(1000);
   }
}

How can I capture if the mouse button is being held down from this thread?

Thanks

Answer 1

The problem is you're trying to mix two GUI technologies: WinForms and WPF. You've set environment suitable for WinForms but trying to use methods from WPF.

You dont need PresentationCore.dll and System.Windows.Input. The desired result can be achieved using System.Windows.Forms.Control class:

public static void ListenerThread()
{
    while (true)
    {
        if ((Control.MouseButtons & MouseButtons.Left) == MouseButtons.Left)
        {
            System.Diagnostics.Debug.WriteLine("Left mouse down");
        }
        Thread.Sleep(1000);
    }
}