Question

有谁能详细解释一下procedure中sender的意义及用法？谢谢！

Answer 1

In an event handler, the Sender parameter indicates which component received the event and therefore called the handler. Sometimes it is useful to have several components share an event handler that behaves differently depending on which component calls it. You can do this by using the Sender parameter in an if...then...else statement. For example, the following code displays the title of the application in the caption of a dialog box only if the OnClick event was received by Button1.procedure TMainForm.Button1Click(Sender: TObject);beginif Sender = Button1 then AboutBox.Caption := 'About ' + Application.Title else AboutBox.Caption := ''; AboutBox.ShowModal;end; 查看原帖>>