动态（以编程方式）添加复选框和已更改事件 [英] Dynamically (programatically) adding check boxes and checkedchanged events

问题描述

我有一些问题，通过编程方式添加了一些复选框和事件处理程序。复选框一切正常，但点击时不执行任何操作。有没有人知道我在做错什么？

I am having a bit of a problem adding a few check boxes and an event handler programatically. The check boxes all appear fine, but they don't do anything when clicked. Does anyone have any idea what I am doing wrong?

foreach (Statement i in theseStatements)
{
    box = new CheckBox();
    box.Text = i.StatementText;
    box.AutoPostBack = true;
    box.CheckedChanged += new EventHandler(this.CheckedChange);
    PlaceHolder.Controls.Add(box);
}

protected void CheckedChange(object sender, EventArgs e) 
{
    CheckBox x = (CheckBox)sender;
    Instructions.Text = "change";            
    WorkPlaceHazardsBox.Text += x.Text;
} 

推荐答案

您应该执行以下操作：

You should do the following:

1. 为 CheckBox的每个实例设置 ID 您在 foreach 循环中创建。


2. 对于PostBack，请确保您的复选框已创建， CheckedChanged 事件处理程序附加在页面生命周期的某个时候，控制事件发生之前

1. Set the ID property for each instance of CheckBox you create in your foreach loop.
2. For PostBacks, ensure that your CheckBoxes are created and CheckedChanged event handler is attached at some point of the page life-cycle before control events are raised

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