public Magnifier(Form form)
{
if (form == null)
{
throw new ArgumentNullException("form");
}
this.form = form;
this.form.Resize += new EventHandler(form_Resize);
this.form.FormClosing += new FormClosingEventHandler(form_FormClosing);
this.updateTimer = new Timer();
this.updateTimer.Interval = WinUser.USER_TIMER_MINIMUM;
this.updateTimer.Tick += new EventHandler(updateTimer_Tick);
this.animateTimer = new Timer();
this.animateTimer.Interval = 50;
this.animateTimer.Tick += new EventHandler(animateTimer_Tick);
this.magnificationFactor = 2.0f;
this.magnificatorWindowRect = new RECT();
this.isInitialized = Magnification.MagInitialize();
if (this.isInitialized)
{
this.CreateMagnifier();
this.updateTimer.Start();
}
}
private void DestroyMagnifier()
{
if (isInitialized)
{
Magnification.MagUninitialize();
}
}
private void CreateMagnifier()
{
if (!this.isInitialized)
{
return;
}
IntPtr hInst = Kernel32.GetModuleHandle(null);
this.form.AllowTransparency = true;
this.form.TransparencyKey = Color.Empty;
this.form.Opacity = 0;
User32.GetClientRect(this.form.Handle, ref this.magnificatorWindowRect);
this.hwndMagnificator = User32.CreateWindow(
0,
Magnification.WC_MAGNIFIER,
"MagnifierWindow",
(int)WinUser.WS_VISIBLE | (int)WinUser.WS_CHILD | (int)Magnification.MagnifierStyle.MS_SHOWMAGNIFIEDCURSOR,
this.magnificatorWindowRect.left,
this.magnificatorWindowRect.top,
this.magnificatorWindowRect.right,
this.magnificatorWindowRect.bottom,
this.form.Handle,
IntPtr.Zero,
hInst,
IntPtr.Zero
);
if (this.hwndMagnificator == IntPtr.Zero)
{
return;
}
Magnification.Transformation matrix = new Magnification.Transformation(this.magnificationFactor);
Magnification.MagSetWindowTransform(this.hwndMagnificator, ref matrix);
}
private void UpdateMaginifier()
{
if (!this.isInitialized || this.hwndMagnificator == IntPtr.Zero)
{
return;
}
//POINT mousePosition = new POINT();
RECT rect = new RECT();
//User32.GetCursorPos(ref mousePosition);
int width = (int)((this.magnificatorWindowRect.right - this.magnificatorWindowRect.left) / this.magnificationFactor);
int height = (int)((this.magnificatorWindowRect.bottom - this.magnificatorWindowRect.top) / this.magnificationFactor);
rect.left = Magnifier.X /*mousePosition.x*/ - width / 2;
rect.top = Magnifier.Y /*mousePosition.y*/ - height / 2;
if (rect.left < 0)
{
rect.left = 0;
}
if (rect.left > User32.GetSystemMetrics(WinUser.SM_CXSCREEN) - width)
{
rect.left = User32.GetSystemMetrics(WinUser.SM_CXSCREEN) - width;
}
if (rect.top < 0)
{
rect.top = 0;
}
if (rect.top > User32.GetSystemMetrics(WinUser.SM_CYSCREEN) - height)
{
rect.top = User32.GetSystemMetrics(WinUser.SM_CYSCREEN) - height;
}
rect.right = rect.left + width;
rect.bottom = rect.top + height;
if (this.form == null)
{
this.updateTimer.Stop();
this.animateTimer.Stop();
return;
}
if (this.form.IsDisposed)
{
this.updateTimer.Enabled = false;
return;
}
Magnification.MagSetWindowSource(this.hwndMagnificator, rect);
User32.SetWindowPos(
this.form.Handle,
Magnification.HWND_TOPMOST,
0,
0,
0,
0,
(int)WinUser.SWP_NOSIZE | (int)WinUser.SWP_NOMOVE | (int)WinUser.SWP_NOACTIVATE
);
User32.InvalidateRect(this.hwndMagnificator, IntPtr.Zero, true);
this.animateTimer.Start();
}