有人可以解释这段代码吗?按钮btn =(按钮)发送器; [英] can someone explain this code? Button btn = (Button)sender;

问题描述

我是初学者

Hii i''m beginner

protected void Button_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
btn.Text = (Int32.Parse(btn.Text) + 1).ToString();

}

推荐答案

sender指调用触发事件处理程序的事件的对象.如果您有许多使用同一事件处理程序的对象，这将很有用.


在此处，应在单击按钮时调用"Button_Click"函数，因此您正在跟踪按钮单击事件.

//Button btn =(Button)sender;

由于按钮是发件人，因此您将创建一个具有相同按钮类的对象，并对该按钮对象进行类型转换并分配给本地对象，然后访问其属性.


如果您有许多使用同一事件处理程序的对象，这将很有用.

sender refers to the object that invoked the event that fired the event handler. This is useful if you have many objects using the same event handler.


Here the "Button_Click" function should be called on the click of a button , hence you are tracking the button click event.

//Button btn = (Button)sender;

as sender is the button , you are creating a object of the same button class and typecasting the button object and assigning to a local object, then accessing it''s properties.


This is useful if you have many objects using the same event handler.

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