/**************************************************************************************************************************/
/* Credit where credit is due: SendMouseInput shamelessly taken from UI Verify - http://uiautomationverify.codeplex.com/ */
/**************************************************************************************************************************/
/// <summary>
/// Inject pointer input into the system
/// </summary>
/// <param name="x">x coordinate of pointer, if Move flag specified</param>
/// <param name="y">y coordinate of pointer, if Move flag specified</param>
/// <param name="data">wheel movement, or mouse X button, depending on flags</param>
/// <param name="flags">flags to indicate which type of input occurred - move, button press/release, wheel move, etc.</param>
/// <exception cref="ProdOperationException">Thrown if Security permissions won't allow execution</exception>
///
/// <exception cref="Win32Exception">Thrown if SendInput call fails</exception>
///
/// <outside_see conditional="false">
/// This API does not work inside the secure execution environment.
/// <exception cref="System.Security.Permissions.SecurityPermission"/>
/// </outside_see>
/// <remarks>
/// x, y are in pixels. If Absolute flag used, are relative to desktop origin.
/// </remarks>
internal static void SendMouseInput(double x, double y, int data, MOUSEEVENTF flags)
{
int intflags = (int)flags;
try
{
if ((intflags & (int)MOUSEEVENTF.MOUSEEVENTFABSOLUTE) != 0)
{
int vscreenWidth = NativeMethods.GetSystemMetrics((int)SystemMetric.SMCXVIRTUALSCREEN);
int vscreenHeight = NativeMethods.GetSystemMetrics((int)SystemMetric.SMCYVIRTUALSCREEN);
int vscreenLeft = NativeMethods.GetSystemMetrics((int)SystemMetric.SMXVIRTUALSCREEN);
int vscreenTop = NativeMethods.GetSystemMetrics((int)SystemMetric.SMYVIRTUALSCREEN);
// Absolute input requires that input is in 'normalized' coords - with the entire
// desktop being (0,0)...(65535,65536). Need to convert input x,y coords to this
// first.
//
// In this normalized world, any pixel on the screen corresponds to a block of values
// of normalized coords - eg. on a 1024x768 screen,
// y pixel 0 corresponds to range 0 to 85.333,
// y pixel 1 corresponds to range 85.333 to 170.666,
// y pixel 2 corresponds to range 170.666 to 256 - and so on.
// Doing basic scaling math - (x-top)*65536/Width - gets us the start of the range.
// However, because int math is used, this can end up being rounded into the wrong
// pixel. For example, if we wanted pixel 1, we'd get 85.333, but that comes out as
// 85 as an int, which falls into pixel 0's range - and that's where the pointer goes.
// To avoid this, we add on half-a-"screen pixel"'s worth of normalized coords - to
// push us into the middle of any given pixel's range - that's the 65536/(Width*2)
// part of the formula. So now pixel 1 maps to 85+42 = 127 - which is comfortably
// in the middle of that pixel's block.
// The key ting here is that unlike points in coordinate geometry, pixels take up
// space, so are often better treated like rectangles - and if you want to target
// a particular pixel, target its rectangle's midpoint, not its edge.
x = ((x - vscreenLeft) * 65536) / vscreenWidth + 65536 / (vscreenWidth * 2);
y = ((y - vscreenTop) * 65536) / vscreenHeight + 65536 / (vscreenHeight * 2);
intflags |= (int)MOUSEEVENTF.MOUSEEVENTFVIRTUALDESK;
}
NPUT mi = new NPUT
{
Type = (int)InputStructType.InputMouse
};
mi.Union.MouseInput.DX = (int)x;
mi.Union.MouseInput.DY = (int)y;
mi.Union.MouseInput.MouseData = data;
mi.Union.MouseInput.DWFlags = intflags;
mi.Union.MouseInput.Time = 0;
mi.Union.MouseInput.DWExtraInfo = new IntPtr(0);
if (NativeMethods.SendInput(1, ref mi, Marshal.SizeOf(mi)) == 0)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
catch (Exception e)
{
throw new ProdOperationException(e.Message, e);
}
}
internal static extern int SendInput(uint nInputs, ref NPUT pInputs, int cbSize);