Enabling and disabling Press and Hold behavior in tabletPCs using WPF

The default behavior of tablet PCs when Pressing the stylus and holding it, is to show a circular animation after a short period which stays visible as a ring for another short period then disappears. If the stylus is lifted during the period the ring is visible, windows will send a right button up event.

It is possible to enable and disable this behavior in WPF by calling three older functions using the PInvoke API.

The three functions involved are

- GlobalAddAtom

- SetProp

- GetProp

This is part of a class that disables the right click behavior for the main application window

//Include these name spaces

using System.Runtime.InteropServices;

using System.Windows.Interop;

public partial class Window1 : Window

{

[DllImport("Kernel32.dll")]

static extern ushort GlobalAddAtom(string lpString);

//ATOM GlobalAddAtom(LPCTSTR lpString);

[DllImport("Kernel32.dll")]

static extern ushort GlobalDeleteAtom(ushort nAtom);

//ATOM GlobalDeleteAtom(ATOM nAtom);

[DllImport("user32.dll")]

static extern int SetProp(IntPtr hWnd, string lpString, int hData);

//BOOL SetProp(HWND hWnd, LPCTSTR lpString, HANDLE hData);

[DllImport("user32.dll")]

static extern int RemoveProp(IntPtr hWnd, string lpString);

//HANDLE RemoveProp(HWND hWnd, LPCTSTR lpString);

ushort pressAndHoldAtomID;

string pressAndHoldAtomStr = "MicrosoftTabletPenServiceProperty";

IntPtr mainWindowHandle;

private void Window_ContentRendered(object sender, EventArgs e) {

// Get the Tablet PC atom ID

pressAndHoldAtomID = GlobalAddAtom(pressAndHoldAtomStr);

if (pressAndHoldAtomID == 0)

MessageBox.Show("GlobalAddAtom failed");

else {

//the next function must be called after the window has

// been rendered, otherwise it returns 0

mainWindowHandle =new

WindowInteropHelper(Application.Current.MainWindow).Handle;

int result = SetProp(

mainWindowHandle, pressAndHoldAtomStr, 1);

}

}

private void Window_Closing(

object sender, System.ComponentModel.CancelEventArgs e)

{

if (pressAndHoldAtomID != 0) {

int result = RemoveProp(

mainWindowHandle, pressAndHoldAtomStr);

GlobalDeleteAtom(pressAndHoldAtomID);

}

}