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 ?
解决方案
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));