以下代码就可以了。给分,呵呵。
procedure TForm1.Button1Click(Sender: TObject);
const
WS_EX_LAYERED = $80000;
WS_EX_TRANSPARENT = $20;
LWA_ALPHA = $2;
var
OldStyle: Integer;
begin
OldStyle := GetWindowLong(Handle, GWL_EXSTYLE);
SetWindowLong(Handle, GWL_EXSTYLE, GetWindowLong(Handle, GWL_EXSTYLE) or
WS_EX_LAYERED);
SetLayeredWindowAttributes(Handle, 0, 125, LWA_ALPHA);
SetWindowLong(Handle, GWL_EXSTYLE, OldStyle or WS_EX_LAYERED or
WS_EX_TRANSPARENT or WS_EX_TOPMOST);
end;
procedure TForm1.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams(Params);
with params do
begin
Style:=WS_POPUP or WS_BORDER;
ExStyle := WS_EX_TOPMOST or WS_EX_NOACTIVATE or WS_EX_WINDOWEDGE;
end;
end;