Run ExternalEvent when some element is selected.

[qoreodlf37]

Hi.

I know that I should use ExternalEvent to do somthing with Transaction in window that opened by Show() not ShowDialog().

This is my sample code.

////This code is run in window by Show()
////externalEventHandeler is custom handler with ExternalEvent and IExternalEventHandler

externalEventHandeler.Event += (s, arg) => {
          //Do something with Transaction.
};
externalEventHandeler.Run();

It usually works well. But when element is selected, the event doesn't run. But the event run when I unselect element.

I searched and understand the reason is Revit UI thread holding 'Element select'.

I want to know run event withoue unselecting element.

How can I do? 

[scgq425]

Hi @qoreodlf37 ：

this error likely push by the thread changed and the external cant notify .

you can try this step : 

1. run code 

2. click revit main window and check that :select element 

3. also you can use this code to set window be revit child 

wpf :

 LoginWindow window = new LoginWindow();
            System.Windows.Interop.WindowInteropHelper mainUi = new System.Windows.Interop.WindowInteropHelper(window)
                {
                    Owner = System.Diagnostics.Process.GetCurrentProcess().MainWindowHandle
                };
            window.ShowDialog();

winform:

var uiView = uiDoc.GetOpenUIViews().First(x => x.ViewId == uiDoc.ActiveView.Id);
            var rec = uiView.GetWindowRectangle();
            var handler = new FindForm.ExecuteEventHandler();
            var externalEvent = ExternalEvent.Create(handler);
            var rvtPtr = Process.GetCurrentProcess().MainWindowHandle;
            FindForm ff = new FindForm(handler,externalEvent,new Point(rec.Left,rec.Top));
            ff.Show(new Command.WindowHandle(rvtPtr));

 public class WindowHandle : IWin32Window
        {
            private IntPtr _handle;

            public WindowHandle(IntPtr h)
            {
                Debug.Assert(IntPtr.Zero != h, "expected non-null window handle");
                LogUtility.Error("expected non-null window handle");
                _handle = h;
            }
            public IntPtr Handle => _handle;
        }

4. if this all null , using the idling + external to select element ,  make the thread to revit 

[ricaun]

What do you mean by element is selected?

Are you selection a element and than click in a button to run the externalEventHandeler?