asp.net无法访问动态创建的控件 [英] asp.net cannot access to dynamically created controls

问题描述

我创建5单选按钮，当我的页面加载：

I am creating 5 radio button when my page is loading :

protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            for (int i = 0; i < 5; i++)
            {
                RadioButton r = new RadioButton();
                r.Text = i.ToString();
                r.ID = i.ToString(); ;
                Panel1.Controls.Add(r);

            }
        }
    }

我想访问他们的另一种方法对应点击按钮，但我不能。

I would like to access them in another method correspond to a click button, but I cannot. :

protected void Button1_Click(object sender, EventArgs e)
    {            
        RadioButton r = (RadioButton)FindControl("2");
        r.Checked = true;             
    }

当我做我的FindControl方法，我得到以下异常：NullReferenceException异常是由用户code未处理

When I am doing my findcontrol method, I get the following exception : nullreferenceexception was unhandled by user code

推荐答案

的FindControl 并没有做深的搜索。您添加单选按钮面板1 ，但调用的FindControl 的页。

FindControl does not do deep search. You added radio buttons to Panel1, but calling FindControl of Page.

RadioButton r = (RadioButton)Panel1.FindControl("2");

另一件事。删除如果（！Page.IsPostBack）状态。当的button1_Click 火灾，页面回发状态，动态控件必须建立，如果你希望找到他们。

Another thing. Remove if (!Page.IsPostBack) condition. When Button1_Click fires, the page is in PostBack state and dynamic controls have to be created if you expect to find them.

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