当鼠标离开我的控制时，如何触发事件？ [英] How can I trigger an event when the mouse leaves my control?

问题描述

如何创建OnMouseLeave事件？

How do I create an OnMouseLeave event?

推荐答案

Andreas解决方案的另一个替代方法是使用 CM_MOUSELEAVE VCL已经在delphi 7中定义的消息。

Another alternative to the Andreas solution, is use the CM_MOUSELEAVE VCL Message which is already defined in delphi 7.

使用插入程序类为 TButton

type
  TButton = class(StdCtrls.TButton)
  private
    FOnMouseLeave: TNotifyEvent;
    procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
  protected
    property OnMouseLeave: TNotifyEvent read FOnMouseLeave write FOnMouseLeave;
  end;


  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure FormCreate(Sender: TObject);
  private
     procedure ButtonMouseLeave(Sender: TObject);
  public
  end;

//handle the message and call the event handler
procedure TButton.CMMouseLeave(var Message: TMessage);
begin
  if (Message.LParam = 0) and Assigned(FOnMouseLeave) then
      FOnMouseLeave(Self);
end;


procedure TForm1.ButtonMouseLeave(Sender: TObject);
begin
   //your code goes here   
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  //assign the event
  Button1.OnMouseLeave:=ButtonMouseLeave;
end;

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