取消选中时，ASP.NET复选框不火的CheckedChanged事件 [英] ASP.NET CheckBox does not fire CheckedChanged event when unchecking

问题描述

我有像这样的ASP.NET内容窗体上的复选框：

I have a CheckBox on an ASP.NET Content Form like so:

<asp:CheckBox runat="server" ID="chkTest" AutoPostBack="true" OnCheckedChanged="chkTest_CheckedChanged" />

在我的code后面我有以下方式：

In my code behind I have the following method:

protected void chkTest_CheckedChanged(object sender, EventArgs e)
{
}

当我加载页面在浏览器中点击复选框它成为检查，页回，我可以看到 chkTest_CheckedChanged 被调用。

When I load the page in the browser and click the CheckBox it becomes checked, the page posts back, and I can see chkTest_CheckedChanged being called.

当我还是那句话就变成选中单击复选框，页面回，但 chkTest_CheckedChanged 不叫。

When I then click the CheckBox again it becomes unchecked, the page posts back, however chkTest_CheckedChanged is not called.

这个过程是可重复的，所以一旦复选框被选中，选中它会触发事件。

The process is repeatable, so once the CheckBox is unchecked, checking it will fire the event.

我有视图状态在web.config中禁用，使视图状态导致此问题消失。我能做些什么有可靠事件触发而视图状态保持禁用？

I have View State disabled in the Web.Config, enabling View State causes this issue to disappear. What can I do to have reliable event firing while the View State remains disabled?

更新：
如果我设置选中=真正的服务器上的标签的情况变得与事件触发时，取消选​​中该复选框，但没有其他各地的方式逆转。

Update: If I set Checked="true" on the server tag the situation becomes reversed with the event firing when un-checking the CheckBox, but not the other way around.

更新2：
我重写的onLoadComplete 在我的网页，并从内部那里我可以证实，的Request.Form [__ EVENTTARGET] 正确设置为我的CheckBox的ID。

Update 2: I've overridden OnLoadComplete in my page and from within there I can confirm that Request.Form["__EVENTTARGET"] is set correctly to the ID of my CheckBox.

推荐答案

实现存储自定义复选框的在经过属性了ControlState- ，而不是的ViewState 可能会解决这个问题，即使复选框有的AutoPostBack = FALSE

Implementing a custom CheckBox that stores the Checked property in ControlState rather than ViewState will probably solve that problem, even if the check box has AutoPostBack=false

不同于视图状态，了ControlState-不能被禁止，可用于存储数据是到控制的行为所必需的。

Unlike ViewState, ControlState cannot be disabled and can be used to store data that is essential to the control's behavior.

我没有一个Visual Studio环境在现在进行测试，但应该是这样的：

I don't have a visual studio environnement right now to test, but that should looks like this:

public class MyCheckBox : CheckBox
{
    private bool _checked;

    public override bool Checked { get { return _checked; } set { _checked = value; } }

    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);
        //You must tell the page that you use ControlState.
        Page.RegisterRequiresControlState(this);
    }

    protected override object SaveControlState()
    {
        //You save the base's control state, and add your property.
        object obj = base.SaveControlState();

        return new Pair (obj, _checked);
    }

    protected override void LoadControlState(object state)
    {
        if (state != null)
        {
            //Take the property back.
            Pair p = state as Pair;
            if (p != null)
            {
                base.LoadControlState(p.First);
                _checked = (bool)p.Second;
            }
            else
            {
                base.LoadControlState(state);
            }
        }
    }
}

更多信息这里。

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