自定义控件响应键盘事件

Question

我自已做了一个控件,想让其响应键盘事件,可是却不行,我不知道还有哪里没有设置,谁帮帮我,以下是声明部分代码type
  TMyImage = class(TCustomPanel)
  private
    FPicture:TPicture;
    procedure Setpicture(const Value: TPicture);
    procedure WMSize(var Msg: TWMSize); message WM_SIZE;
  protected
    procedure Paint; override;
    { Protected declarations }
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    property picture:TPicture read Fpicture write Setpicture;
    property onKeyDown;
    property OnKeyUp;
    property OnClick;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
    property Visible;
  end;

Answer 1

type
  TMyImage = class(TCustomPanel)
  private 
  property OnKeyDown: TKeyEvent read FOnKeyDown write FOnKeyDown;
  property OnKeyPress: TKeyPressEvent read FOnKeyPress write FOnKeyPress;
  property OnKeyUp: TKeyEvent read FOnKeyUp write FOnKeyUp;
。。

Answer 2

type
  TMyPanel = class(TCustomPanel)
...
  Public
  property OnKeyDown: TKeyEvent read FOnKeyDown write FOnKeyDown;
  property OnKeyPress: TKeyPressEvent read FOnKeyPress write FOnKeyPress;
  property OnKeyUp: TKeyEvent read FOnKeyUp write FOnKeyUp;
...
End;type
  TMyImage = class(TMyPanel)
  private
    FPicture:TPicture;
    procedure Setpicture(const Value: TPicture);
    procedure WMSize(var Msg: TWMSize); message WM_SIZE;
  protected
    procedure Paint; override;
    { Protected declarations }
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    property picture:TPicture read Fpicture write Setpicture;
    property onKeyDown;
    property OnKeyUp;
    property OnClick;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
    property Visible;
  end;

Answer 3

楼上的,你测试过吗,继承的属性是可以省略read和write的

Answer 4

今天又做一些调试,要让键盘事件起作用,必须先获得焦点,但其它键可以,最重要的方向键却没法控件,我把TabStop设为false,也不管用,具体代码如下:
控件声明部分如下:type
  TMyImage = class(TCustomPanel)
  private
    FPicture:TPicture;
    procedure Setpicture(const Value: TPicture);
    procedure WMSize(var Msg: TWMSize); message WM_SIZE;
  protected
    procedure Paint; override;
    { Protected declarations }
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    property picture:TPicture read Fpicture write Setpicture;
    property OnClick;
    property OnKeyDown;
    property OnKeyUp;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
    property Visible;
    property TabStop;//添加了这个属性
  end;测试代码如下:procedure TForm1.MyImage1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
var
  s:string;
begin
   s:='OnKeyDown:Key='+inttostr(Key);;
   Edit1.Text:=s; //其它键可以,但就是方向键和Tab键不起作用,只要一按下它们就转换焦点到其它控件上了
end;procedure TForm1.MyImage1Click(Sender: TObject);
begin
  MyImage1.SetFocus;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  MyImage1.TabStop:=false;  //设为false也没屏幕掉方向键和Tab键
end;

Answer 5

控件响应键盘消息先要有交点.
另外如果要处理Tab和方向键有两种方法
A.处理WM_GETDLGCODE消息.
  Inherited;
  Message.Result := Message.Result or DLGC_WANTTAB or DLGC_WANTARROWS;
B.可以处理CN_KeyDown和CN_KeyUp消息.

Answer 6

焦点我是有了,看代码
procedure TForm1.MyImage1Click(Sender: TObject);
begin
  MyImage1.SetFocus;
end;A.处理WM_GETDLGCODE消息.
  Inherited;
  Message.Result := Message.Result or DLGC_WANTTAB or DLGC_WANTARROWS;
我给我具体点好吗,这个在哪儿用