Draw / Paint Outside Form

问题

Can we paint images and draw text... outside a form.. i mean literally outside...

i know its stupid question to ask but CAN we...

回答1:

You can "cheat" by creating a form, and setting its TransparentColor property to its background color, then draw on it. However, this prohibits you from drawing the transparent color because it won't show.

Or you could actually draw directly to the desktop.

[DllImport("User32.dll")]
public static extern IntPtr GetDC(IntPtr hwnd);
[DllImport("User32.dll")]
public static extern void ReleaseDC(IntPtr dc);

---

IntPtr desktopPtr = GetDC(IntPtr.Zero);
Graphics g = Graphics.FromHdc(desktopPtr);

// Do graphics manipulation here with "g" object

// Very important - free desktop graphics.
g.Dispose();
ReleaseDC(desktopPtr);

回答2:

You cannot draw on something that does not exist. The area outside of a form, by that definition, does not exist in the context of the form.

I agree with Henk, though, you can draw on transparent forms.

来源：https://stackoverflow.com/questions/3379306/draw-paint-outside-form