Add some APIs under Windows 2000, you can easily implement translucent forms, the source program is as follows, and if necessary, I added a comment.
Unit unit1;
Interface
Uses
Windows, Messages, Sysutils, Classes, Graphics, Controls, Forms, Dialogs
Const
WS_EX_LAYERED = $ 80000;
AC_SRC_OVER = $ 0;
AC_SRC_ALPHA = $ 1;
AC_SRC_NO_PREMULT_ALPHA = $ 1;
AC_SRC_NO_ALPHA = $ 2;
AC_DST_NO_PREMULT_ALPHA = $ 10;
AC_DST_NO_ALPHA = $ 20;
LWA_COLORKEY = $ 1;
LWA_ALPHA = $ 2;
ULW_COLORKEY = $ 1
ULW_ALPHA = $ 2
ULW_OPAQUE = $ 4
// Newly added constant definition
Type
TFORM1 = Class (TFORM)
Procedure formcreate (Sender: TOBJECT);
Private
{Private Declarations}
public
{Public declarations}
END;
Function sets (hWnd: hwnd; crkey: longint; balpha: byte; dwflags: longint): longint; stdcall; external user32; // function declaration
VAR
FORM1: TFORM1;
IMPLEMENTATION
{$ R * .dfm}
Procedure TFORM1.FormCreate (Sender: TOBJECT);
Var L: longint;
Begin
L: = getWindowlong (Handle, GWL_EXSTYLE);
l: = L or ws_ex_layred;
Setwindowlong (Handle, GWL_EXSTYLE, L);
SetlayeredWindowAttributes (Handle, 0, 180, LWA_ALPHA);
// Second parameter is specified transparent color
// The second parameter is 0 Use the fourth parameter to set the alpha value, from 0 to 255, other I don't know, because there is no API help
END;
End.
