TEdit mit Hintergrund Image

[Hammer]

Hallo

Äh... TEdit hat kein OnPaint oder?

Aktuell kann ich euch folgendes Zeigen.
Anregungen Verbesserungen sind immer Herzlich Willkommen...

Delphi-Quellcode:

unit ImageEdit;

interface

uses
  SysUtils, Classes, Controls, StdCtrls, ExtCtrls, Windows, Messages, Graphics;

type
  TImageEdit = class(TEdit)
  private
    { Private-Deklarationen }
    fBMP : TBitmap ;
    fFocus  : Boolean ;
    procedure WMPaint(var msg: TWMPaint);  message WM_PAINT;
    procedure WMKillFocus(var Message: TWMSetFocus); message WM_KillFocus ;
    procedure WMSetFocus(var Message: TWMSetFocus);  message WM_SetFocus ;

  protected
    { Protected-Deklarationen }

  public
    { Public-Deklarationen }
    constructor Create(aOwner: TComponent); override;
    destructor Destroy; override ;

  published
    { Published-Deklarationen }

  end;



procedure Register;



implementation

procedure Register;
begin
  RegisterComponents('easyLEARN', [TImageEdit]);
end;

{ TImageEdit }

constructor TImageEdit.Create(aOwner: TComponent);
begin
  Inherited ;

  fBMP := TBitmap.Create ;
  fBMP.LoadFromFile('c:\temp\logo_s4u.bmp') ;
end;

destructor TImageEdit.Destroy;
begin
  fBMP.Free ;

  Inherited ;
end;

procedure TImageEdit.WMSetFocus(var Message: TWMSetFocus);
begin
  Inherited;
  fFocus := True ;

  Color := clRed ;  // Hack zum Aufrufen von WMPaint
  Color := clWhite ;  // Hack zum Aufrufen von WMPaint
end;

procedure TImageEdit.WMKillFocus(var Message: TWMSetFocus);
begin
  Inherited;
  fFocus := False ;

  Color := clRed ;  // Hack zum Aufrufen von WMPaint
  Color := clWhite ;  // Hack zum Aufrufen von WMPaint
end;

procedure TImageEdit.WMPaint(var msg: TWMPaint);
var dc : hdc;
    canvas :tcanvas;
begin
  Inherited     ;

  if fBMP = NIL then EXIT ;

  if NOT fFocus then
  begin
    if Length(Text) = 0 then
    begin
      dc  := getdc(Self.Handle);
      canvas:= tcanvas.Create ;
      Canvas.Handle := DC;
      Canvas.Draw(-5, -3, fBMP);
    end;
  end;
end;

end.