请问：关于动态改变窗体的背景图片和颜色的问题，高手请进！！

Question

Image1.LoadFromFile(ExtractFilePath(Application.ExeName)+'\图片名');

Answer 1

blazingfire(烈焰) 
我的也是这样写的。我改变了图片后，再重新执行这个句子时。原来的图片还在。不知如何重画一次。

Answer 2

procedure TMainFrm.DrawStretched;//拉伸
var
  CR: TRect;
begin
  GetWindowRect(ClientHandle, CR);
  StretchBlt(FDrawDC, 0, 0, CR.Right, CR.Bottom,
             imgMain.Picture.Bitmap.Canvas.Handle, 0, 0,
             imgMain.Picture.Width, imgMain.Picture.Height, SRCCOPY);
end;procedure TMainFrm.DrawCentered;//局中
var
  CR: TRect;
begin
  GetWindowRect(ClientHandle, CR);
  with imgMain do
    BitBlt(FDrawDC, ((CR.Right - CR.Left) - Picture.Width) div 2,
                    ((CR.Bottom - CR.Top) - Picture.Height) div 2,
                    Picture.Graphic.Width, Picture.Graphic.Height,
                    Picture.Bitmap.Canvas.Handle, 0, 0, SRCCOPY);
end;procedure TMainFrm.DrawTiled;//平铺
var
  Row, Col: Integer;
  CR, IR: TRect;
  NumRows, NumCols: INteger;begin
  GetWindowRect(ClientHandle, CR);
  IR := imgMain.ClientRect;
  NumRows := CR.Bottom div IR.Bottom;
  NumCols := CR.Right div IR.Right;
  with imgMain do
    for Row :=0 to NumRows+1 do
      for Col :=0 to NumCols+1 do
        BitBlt(FDrawDC, Col*Picture.Width, Row*Picture.Height,
                        Picture.Width, Picture.Height,
                        Picture.Bitmap.Canvas.Handle, 0, 0, SRCCOPY);
end;procedure TMainFrm.ClientWndProc(var Message: TMessage);
begin
  case Message.Msg of
  WM_EraseBKGnd:
    begin
      CallWindowProc(FoldClientProc, ClientHandle, Message.Msg,
                     Message.WParam, Message.LParam);
      FDrawDC := TWMEraseBKGnd(Message).DC;
      DrawStretched;  //拉伸
      //DrawCentered;   //居中
      //DrawTiled;      //平铺
      Message.Result := 1;
    end;
  WM_VSCROLL, WM_HSCROLL:
    begin
      Message.Result := CallWindowProc(FOldClientProc, CLientHandle,
                                  Message.Msg, Message.WParam, Message.LParam);
      InvalidateRect(ClientHandle, nil, True);
    end;
  else
    Message.Result := CallWindowProc(FOldClientProc, CLientHandle,
                                  Message.Msg, Message.WParam, Message.LParam);
  end;
end;procedure TMainFrm.FormCreate(Sender: TObject);
begin
  FNewClientProc := MakeObjectInstance(ClientWndProc);
  FOldClientProc := Pointer(GetWindowLong(ClientHandle, GWL_WNDPROC));
  SetWindowLong(ClientHandle,GWL_WNDPROC,LongInt(FNewClientProc));
end;重新装入新图片时，运行FormCreate中的代码

Answer 3

clear
loadfromfile()
refrish;