I'm building a gesture system for the Kinect SDK in a C#/WPF app. I want to add a gesture for Magnifier zoom in and out. I'd prefer to use the built-in Windows Magnifier or its underlying logic, but any way to get a similar effect (multiple-monitor aware) would work.
How can I programatically invoke the zoom features of the Windows Magnifier?
So far, the only thing I've found with any hope is to start the process and click the button through Win32; but when I do that, it's pulling up a blank, empty window when I call the Magnifier window's handle.
I've patched this code together through a combination of what I know of C#, a bunch of Win32 API calls I don't really know that well, and a ton of Googling.
private void ZoomIn()
{
// Make sure the Magnifier is running, and get its handle
if (Process.GetProcesses().Where(p => p.ProcessName.ToLower() == "magnify").Count() == 0) {
Process.Start("magnify.exe");
System.Threading.Thread.Sleep(500); }
IntPtr handle = Process.GetProcesses().Where(p => p.ProcessName.ToLower() == "magnify").First().Handle;
// Figure out what size ("mode") it's in
WINDOWPLACEMENT placement = new WINDOWPLACEMENT();
placement.length = Marshal.SizeOf(placement);
GetWindowPlacement(handle, ref placement);
// Move the Magnifier to a predetermined location so we know where to click
MoveWindow(handle, new Point(0, 0));
// If Magnifier is in small mode, click it to put it in big mode.
if (placement.rcNormalPosition.Size.Width == 132) {
SetCursorPos(15, 15);
mouse_event((int)HardwareEvents.MouseLeftDown, 15, 15, 0, 0);
mouse_event((int)HardwareEvents.MouseLeftUp, 15, 15, 0, 0); }
// Click the zoom in button. Yeah, I know, hackish. Isn't Win32 awesome?
SetCursorPos(25, 25);
mouse_event((int)HardwareEvents.MouseLeftDown, 25, 25, 0, 0);
mouse_event((int)HardwareEvents.MouseLeftUp, 25, 25, 0, 0);
}
private void MoveWindow(IntPtr handle, Point point)
{
// TODO: Figure out how to look up the target window's size
SetWindowPos(handle, new IntPtr((int)SpecialWindowHandles.HWND_TOP), (int)point.X, (int)point.Y, 500, 500, SetWindowPosFlags.ShowWindow);
}
private struct WINDOWPLACEMENT {
public int length;
public int flags;
public int showCmd;
public System.Drawing.Point ptMinPosition;
public System.Drawing.Point ptMaxPosition;
public System.Drawing.Rectangle rcNormalPosition; }
[DllImport("user32.dll")]
static extern bool GetWindowPlacement(IntPtr hWnd, ref WINDOWPLACEMENT lpwndl);
[DllImport("user32.dll")]
static extern bool SetCursorPos(int X, int Y);
public static class HardwareEvents
{
public static int MouseMove = 0x0001;
public static int MouseLeftDown = 0x0002, MouseLeftUp = 0x0004;
public static int MouseRightDown = 0x0008, MouseRightUp = 0x0010; // best guess on the 0010
public static int MiddleMouseDown = 0x20, MiddleMouseUp = 0x40;
public static int MouseWheel = 0x800;
}