制作放两个小图片的按钮 - 回复 "xhui" 的问题

问题来源: http://www.cnblogs.com/del/archive/2009/03/12/1409708.html#1475240

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本例效果图:

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自定义的类(TMyButton):

---

unit Unit2;

interface

uses
  Windows, Messages, Classes, Graphics, StdCtrls;

type
  TMyButton = class(TButton)
  private
    FBit1,FBit2: TBitmap;
  protected
    procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Click; override;
  end;

implementation

{ TMyButton }

procedure TMyButton.Click;
begin
  inherited;
  MessageBox(0, 'MyButton', 'Hi', MB_OK);
end;

constructor TMyButton.Create(AOwner: TComponent);
var
  wh: Integer;
begin
  inherited;
  FBit1 := TBitmap.Create;
  FBit2 := TBitmap.Create;
  //在此可以载入图片, 为了测试方便, 我随便画两个矩形吧
  wh := Height - 8;
  FBit1.SetSize(wh, wh);
  FBit2.SetSize(wh, wh);
  FBit1.Canvas.Brush.Color := clRed;
  FBit1.Canvas.Rectangle(0, 0, wh, wh);
  FBit2.Canvas.Brush.Color := clLime;
  FBit2.Canvas.Rectangle(0, 0, wh, wh);
end;

destructor TMyButton.Destroy;
begin
  FBit1.Free;
  FBit2.Free;
  inherited;
end;

procedure TMyButton.WMPaint(var Message: TWMPaint);
var
  cvs: TCanvas;
  DC: HDC;
begin
  Inherited;
  DC := GetDC(Handle);
  cvs := TCanvas.Create;
  cvs.Handle := DC;
  cvs.Draw(4, (Height - FBit2.Height) div 2, FBit1);
  cvs.Draw(Width - FBit2.Width - 4, (Height - FBit2.Height) div 2, FBit2);
  cvs.Free;
  ReleaseDC(Handle, DC);
end;

end.

测试代码:

---

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses Unit2;

procedure TForm1.Button1Click(Sender: TObject);
begin
  with TMyButton.Create(Self) do begin
    Parent := Self;
    Left := Random(Self.ClientWidth - Width);
    Top := Random(Self.ClientHeight - Height);
  end;
end;

end.