我在image1里显示一副bmp图象，我想点击按钮把他平均分成4份，显示在image2,image3,image4,image5里，怎么才能完成啊？

Question

可以使用API函数BitBlt分四个部分拷贝。

Answer 1

image2.Canvas.CopyRect(Image2.ClientRect, Image1.Canvas,Rect(0,0,Image1.ClientWidth div 2,Image1.ClientHeight div 2));
...

Answer 2

uses Types; //for Delphi6(*
function OffsetRect(var Rect: TRect; DX: Integer; DY: Integer): Boolean;
begin
  if @Rect <> nil then // Test to increase compatiblity with Windows
  begin
    Inc(Rect.Left, DX);
    Inc(Rect.Right, DX);
    Inc(Rect.Top, DY);
    Inc(Rect.Bottom, DY);
    Result := True;
  end
  else
    Result := False;
end;
*)
procedure TForm1.Button1Click(Sender: TObject);
var
  vRectT: TRect;
  vRect0: TRect;
begin
  vRect0 := Rect(0, 0, Image1.Picture.Bitmap.Width div 2,
    Image1.Picture.Bitmap.Height div 2);  vRectT := vRect0;
  OffsetRect(vRectT, 0, 0);
  Image2.Picture.Bitmap.Width := vRect0.Right;
  Image2.Picture.Bitmap.Height := vRect0.Bottom;
  Image2.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  vRectT := vRect0;
  OffsetRect(vRectT, Image1.Picture.Bitmap.Width div 2, 0);
  Image3.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  vRectT := vRect0;
  OffsetRect(vRectT, 0, Image1.Picture.Bitmap.Height div 2);
  Image4.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  vRectT := vRect0;
  OffsetRect(vRectT, Image1.Picture.Bitmap.Width div 2, Image1.Picture.Bitmap.Height div 2);
  Image5.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  Image3.Left := Image2.Left + Image2.Width;
  Image3.Top := Image2.Top;  Image4.Left := Image2.Left;
  Image4.Top := Image2.Top + Image2.Height;  Image5.Left := Image2.Left + Image2.Width;
  Image5.Top := Image2.Top + Image2.Height;
end;

Answer 3

uses Types; //for Delphi6(*
function OffsetRect(var Rect: TRect; DX: Integer; DY: Integer): Boolean;
begin
  if @Rect <> nil then // Test to increase compatiblity with Windows
  begin
    Inc(Rect.Left, DX);
    Inc(Rect.Right, DX);
    Inc(Rect.Top, DY);
    Inc(Rect.Bottom, DY);
    Result := True;
  end
  else
    Result := False;
end;
*)
procedure TForm1.Button1Click(Sender: TObject);
var
  vRectT: TRect;
  vRect0: TRect;
begin
  vRect0 := Rect(0, 0, Image1.Picture.Bitmap.Width div 2,
    Image1.Picture.Bitmap.Height div 2);  vRectT := vRect0;
  OffsetRect(vRectT, 0, 0);
  Image2.Picture.Bitmap.Width := vRect0.Right;
  Image2.Picture.Bitmap.Height := vRect0.Bottom;
  Image2.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  vRectT := vRect0;
  OffsetRect(vRectT, Image1.Picture.Bitmap.Width div 2, 0);
  Image3.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  vRectT := vRect0;
  OffsetRect(vRectT, 0, Image1.Picture.Bitmap.Height div 2);
  Image4.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);//查看用
  vRectT := vRect0;
  OffsetRect(vRectT, Image1.Picture.Bitmap.Width div 2, Image1.Picture.Bitmap.Height div 2);
  Image5.Canvas.CopyRect(vRect0, Image1.Canvas, vRectT);  Image3.Left := Image2.Left + Image2.Width;
  Image3.Top := Image2.Top;  Image4.Left := Image2.Left;
  Image4.Top := Image2.Top + Image2.Height;  Image5.Left := Image2.Left + Image2.Width;
  Image5.Top := Image2.Top + Image2.Height;
end;

Answer 4

to zswang(伴水)(* 嘻 *):
   算你狠，给你分！