[Question] GDI+ Clear() function

[DrakeFish]

I successfully made a transparent window where I want to draw using GDI+ in C#. The problem is that when I call the Clear function, even with "Colors.Transparent", it fills the window with some color... My hint is to draw on top of the other window behind mine, and I couldn't find something that really only clear the screen, without filling it with a colour, yet. Anyone has an idea?

If this isn't possible in GDI+, would it be possible in DirectX 2D ?

[suicidity]

...
{
	SetWindowLong(this.Handle, -20, (IntPtr)(GetWindowLong(this.Handle, -20) ^ 0x80000 ^ 0x20));
	SetLayeredWindowAttributes(this.Handle, 0, 255, 0x2);
}

[DllImport("user32.dll")]
int SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);
[DllImport("user32.dll")]
bool SetLayeredWindowAttributes(IntPtr hWnd, uint crKey, byte bAlpha, uint dwFlags);

Small anti-copypasta, But you should figure it out.

[DrakeFish]

I found out how, i don't know why I didn't think about it but I've set my Form Transparency Key to Lime, and then used Clear(Color.Lime), the only problem is that it flickers way too much, so I will try using D3D and see if I get better results.

[suicidity]

That's a cheesy way of doing it, and results in terrible stuff; Do what I recommended and you'll be fine.

[DrakeFish]

...
{
	SetWindowLong(this.Handle, -20, (IntPtr)(GetWindowLong(this.Handle, -20) ^ 0x80000 ^ 0x20));
	SetLayeredWindowAttributes(this.Handle, 0, 255, 0x2);
}

[DllImport("user32.dll")]
int SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);
[DllImport("user32.dll")]
bool SetLayeredWindowAttributes(IntPtr hWnd, uint crKey, byte bAlpha, uint dwFlags);

Small anti-copypasta, But you should figure it out.

What does that do exactly, I am looking for something that will make the window flicker less when using Clear, or something to replace the Clear. I don't get when in the script I'm supposed to use those 2 lines.

[suicidity]

Helping you is pointless.. But as you already have the solution, have fun trying to copy paste it.

[DrakeFish]

I found my solution by using DirectX, which is 100x better since there's no flicker at all, which is what i wanted.
Also, thanks for the tip on using SetLayeredWindowAttributes.