Invoke Windows Magnifier

Question

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;
}

Answer 1

Solved. This code sends a Win + keystroke.

        keybd_event(0x5B, 0x45, 0, new UIntPtr(0));
        keybd_event(0xBB, 0x45, 1, new UIntPtr(0));

http://msdn.microsoft.com/en-us/library/ms646280(v=vs.85).aspx