Want Windows 8.1 / 10 Desktop View, using virtual mouse clicks functions on Windows On-Screen Keyboard Keys (source code C# WPF program)

When use PC Windows using virtual mouse functions to moving mouse cursor position and send virtual mouse click actions: such as mouse left-click command, But the virtual mouse click commands will not work on the Windows Desktop On-Screen Keyboard keys. Example: Have display: Windows 8.1 / 10 On-Screen Keyboard shows on Desktop view. C# WPF program has Using [DllImport("[login to view URL], .....)] virtual mouse functions for control virtual mouse cursor moving and mouse click actions commands To test the program: set "A" for moving Left, "S" for moving Down, "W" for moving Up, and "D" for moving Right. and "Space" for do virtual mouse Left click. But, The virtual mouse click actions will not work on the On-screen Keyboard keys. if moving to On-screen Keyboard key "A", and do virtual mouse left-click, will not works. Want C# WPF function virtual mouse click solution: Windows 8.1 / 10 Desktop View, using virtual mouse clicks functions on Windows On-Screen Keyboard Keys (source code C# WPF program) Development platform: Visual Studio 2013 .NET Framework 4.5 Language: C# Application: WPF, Windows Presentation Foundation Windows 8.1, Windows 10 App development Required: Submit completed C# WPF source code program, And Need Sign an IP Agreement (Freelancer), Intellectual Property Transfer Agreement