c# - 查找控件()不工作

Question

我在按钮点击事件中创建了 5 个文本框，我必须在点击动态生成的按钮时获取文本框中的值。

protected void Button1_Click(object sender, EventArgs e)
 {
  for(int i=0;i<5;i++)
  {
   HtmlGenericControl tr = new HtmlGenericControl("tr");
   HtmlGenericControl td = new HtmlGenericControl("td");
   HtmlGenericControl tdbtn = new HtmlGenericControl("td");           
   TextBox txt=new TextBox();
   txt.ID="txt_"+i.ToString();
   td.Controls.Add(txt);  
   Button btn=new Button();
   btn.ID="btn_"+i.ToString();
   btn.Click+=new EventHandler(btnpay_Click);
   btn.Text="Pay";    
   tdbtn.Controls.Add(btn);        
   tr.Controls.Add(td);
   tr.Controls.Add(tdbtn);
   PlaceHolder1.Controls.Add(tr);
}

但我无法在 btnpay_Click 的文本框中获取值

protected void btnpay_Click(object sender, EventArgs e)
    {

        Button btn = new Button();
        btn = sender as Button;
        string[] splitvaues = btn.ID.Split('_');
        string identity = splitvaues[1];
        TextBox txt = new TextBox();
        txt =PlaceHolder1.FindControl("txt_" + identity) as TextBox;

}

谁能告诉我解决这个问题的方法？

Answer 1

你的问题是FindControl不会递归控制树。它只直接在 ControlCollection 中搜索控件容器。

This method will find a control only if the control is directly contained by the specified container; that is, the method does not search throughout a hierarchy of controls within controls.

您需要编写一个递归的 FindControl。像这样的东西:

public static Control FindControlRecursive(this Control control, string id)
{
  if (control == null || control.ID == id) return control;

  foreach (var c in control.Controls)
  {
    var found = c.FindControlRecursive(id);
    if (found != null) return found;
  }

  return null;
}