Delphi：将 TImage 置于前面

看下图：

如您所见，我无法将按钮发送到后面。这仅适用于标签。

那么我该如何发送TImage到前面以其透明度.

顺便说一句我读过这个相关问题 https://stackoverflow.com/questions/5369681/controls-on-top-like-tpanel-can-do/5369707#5369707但没有帮助我。因为运行 Andreas Rejbrand 的代码后您甚至无法单击按钮。不仅是按钮，还有所有东西（比如图中的滚动条）

Edit:我不想在将其发送回图像后使该按钮可访问。只想带TImage到一切的前面。

Thanks.

接近目标的一种方法是使用 TWincontrol 的插入器类，并在绘制完它们之后，使用 TControlCanvas 和“挂钩”WM_PAINT 绘制在其上移动的图像。
该代码使用半透明 PNG 图像显示原始草稿，并且可能会得到增强。

unit Unit2;

interface

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

type
  TButton=Class (StdCtrls.TButton)
      Procedure WMPaint(var MSG:TMessage);Message WM_Paint;
  End;
  TEdit=Class (StdCtrls.TEdit)
      Procedure WMPaint(var MSG:TMessage);Message WM_Paint;
  End;

  TForm2 = class(TForm)
    Image1: TImage;
    SpeedButton1: TSpeedButton;
    Button1: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

{ TButton }

procedure TButton.WMPaint(var MSG: TMessage);
var
  cc:TControlCanvas;
begin
   inherited;
    CC:=TControlCanvas.Create;
    CC.Control := TControl(Self);
    CC.Draw(-Left,-Top,Form2.Image1.Picture.Graphic);
    CC.Free;
end;

procedure TEdit.WMPaint(var MSG: TMessage);
var
  cc:TControlCanvas;
begin
   inherited;
    CC:=TControlCanvas.Create;
    CC.Control := TControl(Self);
    CC.Draw(-Left,-Top,Form2.Image1.Picture.Graphic);
    CC.Free;

end;

end.

另一个（更好的）“挂钩”位置将是压倒一切的画图窗口

unit Unit2;

interface

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

type
  TButton=Class (StdCtrls.TButton)
      procedure PaintWindow(DC: HDC);override;
  End;
  TEdit=Class (StdCtrls.TEdit)
      procedure PaintWindow(DC: HDC);override;
  End;

  TForm2 = class(TForm)
    Image1: TImage;
    SpeedButton1: TSpeedButton;
    Button1: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

{ TButton }

procedure TButton.PaintWindow(DC: HDC);
var
  cc:TCanvas;
begin
   inherited;
    CC:=TCanvas.Create;
    CC.Handle := DC;
    CC.Draw(-Left,-Top,Form2.Image1.Picture.Graphic);
    CC.Free;
end;

procedure TEdit.PaintWindow(DC: HDC);
var
  cc:TCanvas;
begin
   inherited;
    CC:=TCanvas.Create;
    CC.Handle := DC;
    CC.Draw(-Left,-Top,Form2.Image1.Picture.Graphic);
    CC.Free;

end;

end.