Teach you to doodle on the table

I once said a famous saying: Graffiti is a great pleasure in life.

As long as you know the graffiti, graffiti is very fun. In the window to draw more, not happy, want to draw on the desktop? Don't be surprised, it's OK.

The graphics class can use a static method Fromhwnd to create an instance, and if you want to doodle on the desktop, just get the handle on the desktop. So how do you get the handle to the desktop? To use an unmanaged API, that is,

[DllImport ("User32.dll")]  
public extern static IntPtr GetDesktopWindow ();

Use it to get the handle of the desktop, as long as there is a handle, you can create graphics, as long as you create a graphics object, you want to draw a ghost on it, Ah Mao ah can be.

Just like I gave myself a speech today, let's enjoy my calligraphy.