如何在C＃中直接在屏幕上绘图？ （示例导致PInvokeStackImbalance）

Question

I want to draw directly on the desktop ( As wallpaper or over all, I don't mind ) in C#, but I have not been able to find how. I found this:

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Runtime.InteropServices;

class Program {
    [DllImport("User32.dll")]
    static extern IntPtr GetDC(IntPtr hwnd);

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

    static void Main(string[] args) {
        IntPtr desktop = GetDC(IntPtr.Zero);
        using (Graphics g = Graphics.FromHdc(desktop)) {
            g.FillRectangle(Brushes.Red, 0, 0, 100, 100);
        }
        ReleaseDC(desktop);
    }
}

It actually draws a red rectangle but within 1 second, Visual Studio gives me this error:

PInvokeStackImbalance was detected

Any help is appreciated, Thanks

Answer 1

you can not draw directly to the desktop with C#. Basically you are going to have to get the bitmap that is being used as the wallpaper, draw on that, then save that to disk and set that as the active wallpaper.

look at this SO question for pointers

Answer 2

You could create a top level window that does not have any chrome and then push it to the back of the z-order for the current set of top level windows. Then you would draw into the client area of that window just like any other C# window.