Invoking control from a different thread fails with a cross-threading exception

Question

In a windows forms project i have subscribed to global keyboard event using win32 api to fire an event when i press win + alt + E, in the event handler i have this code:

    _rectangle = new ScreenBoundingRectangle();
    _rectangle.Location = Location;
    _rectangle.Visible = true;

i keep a variable to my rectangle, now based on some logic, i want to hide the rectangle so i set the visibility to false using this line of code:

    _rectangle.Visible = false;

However i get the famous cross threading exception, even if i try this :

this.Invoke(new MethodInvoker(() =>
    {
        _rectangle.Visible = false;
    }));

i still get the cross threading exception!

the _rectangle does not have invoke method, is there is any other way around this ?

What is the full type of `ScreenBoundingRectangle`? It doesn't seem to be a BCL class. — Jason Watkins, May 15 '15 at 01:03
@JasonWatkins, VisualUIAVerify.Utils.ScreenBoundingRectangle, — Stacker, May 15 '15 at 01:10
Fixed it, had to download the open source file for ScreenboundingRectangle and invoke the underline control used to make the Rectangle, i will post an answer in a little bit, not sure why its not there by design since this is official library! — Stacker, May 15 '15 at 01:17
possible duplicate of [Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on](http://stackoverflow.com/questions/142003/cross-thread-operation-not-valid-control-accessed-from-a-thread-other-than-the) — Alex, May 15 '15 at 04:10

score 0 · Accepted Answer · answered May 15 '15 at 01:20

just for anyone who would use the VisualUIAVerify library and would face this issue:

download the open source and add this to the Visiable property of the ScreenBoundingRectangle

        public bool Visible
        {
            get { return this._visible; }
            set
            {
                this._visible = value;

                if (value)
                    SafeNativeMethods.ShowWindow(_form.Handle, 8);
                else
                {
                    //Here invoke _form:
                    this._form.Invoke(new MethodInvoker(() =>
                    {
                        _form.Hide();
                    }));

                }
            }
        }

Invoking control from a different thread fails with a cross-threading exception

1 Answers1