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Disable the RealTimeStylus for WPF Applications

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Windows Presentation Foundation (WPF) has built in support for processing Windows 7 touch input. The support comes through the tablet platform’s real-time stylus input as OnStylusDown, OnStylusUp, and OnStylusMove events. Windows 7 also provides multi-touch input as Win32 WM_TOUCH window messages. These two APIs are mutually exclusive on the same HWND. Enabling touch input via the tablet platform (the default for WPF applications) disables WM_TOUCH messages. As a result, to use WM_TOUCH to receive touch messages from a WPF window, you must disable the built-in stylus support in WPF. This is applicable in a scenario such as a WPF window hosting a component that uses WM_TOUCH.

To disable WPF listening to stylus input, remove any tablet support added by the WPF window.

Example

The following sample code shows how to remove the default tablet platform support by using reflection.

public static void DisableWPFTabletSupport()  
{  
    // Get a collection of the tablet devices for this window.
    TabletDeviceCollection devices = System.Windows.Input.Tablet.TabletDevices;  
  
    if (devices.Count > 0)  
    {
        // Get the Type of InputManager.  
        Type inputManagerType = typeof(System.Windows.Input.InputManager);  
  
        // Call the StylusLogic method on the InputManager.Current instance.  
        object stylusLogic = inputManagerType.InvokeMember("StylusLogic",  
                    BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.NonPublic,  
                    null, InputManager.Current, null);  
  
        if (stylusLogic != null)  
        {  
            //  Get the type of the stylusLogic returned from the call to StylusLogic.  
            Type stylusLogicType = stylusLogic.GetType();  
  
            // Loop until there are no more devices to remove.  
            while (devices.Count > 0)  
            {  
                // Remove the first tablet device in the devices collection.  
                stylusLogicType.InvokeMember("OnTabletRemoved",  
                        BindingFlags.InvokeMethod | BindingFlags.Instance | BindingFlags.NonPublic,  
                        null, stylusLogic, new object[] { (uint)0 });  
            }
        }  
  
    }  
}

See also