WPF - problem when invoking System.Windows.Forms.SendKeys.Send("{ESC}")-CodePudding

In my Autodesk Revit plugin, I have a modeless WPF window opened on top of Revit. On that window, I have a checkbox that decides on the selection mode in Revit app. Each time the mode is toggled on the checkbox I need to send the "ESC" key to Revit so that it cancels the current mode and enters the other mode (Revit throws an exception when ESC is sent, I invoke the other mode from catch statement recursively)".

Here is the current code:

<CheckBox IsChecked="{Binding Path=IsMultiselection}" Checked="multiselection_chk_Checked" Unchecked="multiselection_chk_UnChecked">

private void multiselection_chk_Checked(object sender, RoutedEventArgs e)
{
    MultiselectChanged = true;

    ActivateRevitWindow();
    System.Windows.Forms.SendKeys.Send("{ESC}");
}

private void multiselection_chk_UnChecked(object sender, RoutedEventArgs e)
{
    MultiselectChanged = true;

    ActivateRevitWindow();
    System.Windows.Forms.SendKeys.Send("{ESC}");
}

public class ViewModel : INotifyPropertyChanged
{
    private bool _isMultiselection;
    public bool IsMultiselection
    {
        get => _isMultiselection;
        set
        {
            _isMultiselection = value;
            OnPropertyChanged();
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

The problem I'm currently facing is that although the selection mode is toggled correctly in Revit the UI of my window is not updating - the checkbox is constantly unchecked. I noticed that if I put any code after System.Windows.Forms.SendKeys.Send("{ESC}"); it won't be reached while I'm debugging if I comment out this line the UI is working fine but the selection mode won't toggle in Revit.

Any ideas of how to fix this already whacky solution?

CodePudding user response：

Eventually I fixed this issue by replacing System.Windows.Forms.SendKeys.Send("{ESC}"); with following code:

[DllImport("user32.dll", SetLastError = true)]
public static extern bool PostMessage(IntPtr hWnd, int Msg, System.Windows.Forms.Keys wParam, IntPtr lParam);

const int WM_KEYDOWN = 0x0100;

public void PressEsc()
{
    PostMessage(RevitWindowHandle, WM_KEYDOWN, System.Windows.Forms.Keys.Escape, IntPtr.Zero);
}

Inspiration came from this answer.