Question

Many programs (True Transparancy and others) can get all active or running in background window class names like this one:

Delphi 7 Object Inspector name is tpropertyinspector

Opera main window class name is operawindowclass
etc.

So how to get any opened window class name in Delphi?

Answer 1

Call EnumWindows to get all the top level windows. Then call GetClassName to find out the window class name for each window. If you also wish to probe child windows then call EnumChildWindows on each top level window.

Call GetClassName like this:

var
  ClassName: string;
  len: Integer;
...
SetLength(ClassName, 256);
len := GetClassName(window, PChar(ClassName), Length(ClassName));
if len=0 then
  RaiseLastOSError;
SetLength(ClassName, len);