unit YJBoard;
interface
uses
Windows, Messages, SysUtils, Classes, Controls, Graphics, ExtCtrls;
const
sc_DragMove: LongInt = $F012;
type
TDirection = (dUp, dDown, dLeft, dRight);
TYJBoard = class(TCustomControl)
private
FBoardTag : integer;
FDirection : TDirection;
MouseX : integer;
MouseY : integer;
FPicture: TPicture;
FCanvas: TControlCanvas;
FDrawing: Boolean;
procedure getBoardTag(Value: integer);
function setBoardTag : integer;
function GetCanvas: TCanvas;
procedure SetPicture(Value: TPicture);
{ Private declarations }
protected
{ Protected declarations }
public
{ Public declarations }
procedure Paint;
override;
property Canvas: TCanvas read GetCanvas;
procedure CreateParams(var Params: TCreateParams);
override;
procedure WmLButtonDown(var Msg: TWmLButtonDown);
message wm_LButtonDown;
procedure WmMove(var Msg: TWmMove);
message wm_Move;
published
{ Published declarations }
constructor Create(AOwner: TComponent);
override;
destructor Destroy;
override;
property BoardTag : integer read FBoardTag;
property Picture: TPicture read FPicture write SetPicture;
end;
implementation
var
TempPicture : TPicture;
//构造
constructor TYJBoard.Create(AOwner: TComponent);
var
FullRgn, NewRgn : Integer;
begin
inherited Create(AOwner);
FCanvas := TControlCanvas.Create;
FCanvas.Control := Self;
TempPicture := TPicture.Create;
TempPicture.LoadFromFile('E:/Sample.bmp');
//FCanvas.StretchDraw(Rect(0, 0, 100, 100), TempPicture.Bitmap.Canvas);
// TempCanvas.Control := Self;
Left := 20;
Top := 20;
Width := 100;
Height := 100;
//完整区域
//FullRgn := CreateRectRgn(10, 10, 90, 90);
//异型区域
//NewRgn := CreateRoundRectRgn(0, 0, 20, 20, 20, 20);
//合并区域，从参2中按参四方式与参3进行运算，返回值传给参1，参4值RGN_DIFF为减去，RGN_OR为合并
//CombineRgn(FullRgn, FullRgn, NewRgn, RGN_OR);
//设置可见区域
//SetWindowRgn(Self.Handle, FullRgn, TRUE);
end;
//析构
destructor TYJBoard.Destroy;
begin
FCanvas.Free;
inherited Destroy;
end;
//过程
procedure TYJBoard.SetPicture(Value: TPicture);
begin
FPicture.Assign(Value);
end;
procedure TYJBoard.WmMove(var Msg: TWmMove);
begin
Invalidate;
end;
procedure TYJBoard.WmLButtonDown(var Msg: TWmLButtonDown);
begin
// Perform(wm_SysCommand, sc_DragMove, 0);
Perform(WM_SYSCOMMAND, $F012, 0);
end;
procedure TYJBoard.Paint;
begin
// Canvas.CopyRect(Rect(0, 0, 100, 100), TempPicture.Bitmap.Canvas, Rect(0, 0, 100, 100));
BitBlt(Self.Canvas.Handle, 0, 0, 100, 100, TempPicture.Bitmap.Canvas.Handle, 0, 0, SRCCopy);
end;
procedure TYJBoard.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams(Params);
Params.ExStyle := Params.ExStyle + ws_ex_Transparent;
end;
procedure TYJBoard.getBoardTag(Value: integer);
begin
FBoardTag := Value;
end;
//函数
function TYJBoard.GetCanvas: TCanvas;
begin
Result := FCanvas;
end;
function TYJBoard.setBoardTag : integer;
begin
Result := FBoardTag;
end;
end.
以上代码能运行，但有闪烁。
