How to convert workspace coordinates to screen coordinates?

问题

I want to convert the workspace coordinates returned by GetWindowPlacement in rcNormalPosition.Left and rcNormalPosition.Top to screen coordinates that I can assign later to MainForm.Left and MainForm.Top. How can I do that ?

回答1:

The simplest and cleanest way is to use the API function that partners with GetWindowPlacement, namely SetWindowPlacement. That way you don't need to convert between workspace and screen coordinates because you let the system do the work for you.

var
  WindowPlacement: TWindowPlacement;
....
WindowPlacement.length := SizeOf(WindowPlacement);
Win32Check(GetWindowPlacement(Handle, WindowPlacement));
....
Win32Check(SetWindowPlacement(Handle, WindowPlacement));

In the above code, Handle is assumed to be the window handle of the form.

If you have persisted the left and top then you'd restore them like this:

var
  WindowPlacement: TWindowPlacement;
....
WindowPlacement.length := SizeOf(WindowPlacement);
Win32Check(GetWindowPlacement(Handle, WindowPlacement));
WindowPlacement.rcNormalPosition.Left := NewLeft;
WindowPlacement.rcNormalPosition.Top := NewTop;
Win32Check(SetWindowPlacement(Handle, WindowPlacement));

回答2:

You can use the monitor property of your form to determine if the workspace of the monitor that the form is on has got any offset with the monitor's placement. E.g.

ScreenLeft := wplc.rcNormalPosition.Left + 
                Monitor.WorkareaRect.Left - Monitor.Left;
ScreenTop := wplc.rcNormalPosition.Top + 
                Monitor.WorkareaRect.Top - Monitor.Top;

来源：https://stackoverflow.com/questions/29747238/how-to-convert-workspace-coordinates-to-screen-coordinates

标签

Delphi

coordinates

delphi-2009