将服务器端事件添加到扩展程序控件

Question

我有一个扩展程序控件,OnTextChanged在用户输入完成后500ms 引发文本框的事件.这个问题是OnTextChanged当文本框失去焦点时会引发问题,这会导致问题(因为回发).

我想做的是给扩展器控制它自己的服务器端事件(比如说OnDelayedSubmit),所以我可以单独处理它.该事件将起源于扩展器控件的行为脚本(在500ms延迟之后),因此放入__doPostBackin onchanged不是一个选项.

任何人都可以阐明如何解决这个问题吗？

Answer 1

在充分阅读了扩展程序控件和JavaScript之后,我拼凑了一个迄今为止似乎正在运行的解决方案.

主要技巧是从服务器端获取必要的回发代码到客户端行为脚本.我通过使用ExtenderControlProperty(在控件的OnPreRender函数中设置),然后在行为脚本中进行评估来完成此操作.剩下的就是基本的事件处理.

所以现在我的扩展控件的.cs文件看起来像这样:

public class DelayedSubmitExtender : ExtenderControlBase, IPostBackEventHandler
{
    // This is where we'll give the behavior script the necessary code for the 
    // postback event
    protected override void OnPreRender(EventArgs e)
    {
        string postback = Page.ClientScript.GetPostBackEventReference(this, "DelayedSubmit") + ";";
        PostBackEvent = postback;
    }

    // This property matches up with a pair of get & set functions in the behavior script
    [ExtenderControlProperty]
    public string PostBackEvent
    {
        get
        {
            return GetPropertyValue<string>("PostBackEvent", "");
        }
        set
        {
            SetPropertyValue<string>("PostBackEvent", value);
        }
    }

    // The event handling stuff
    public event EventHandler Submit;  // Our event

    protected void OnSubmit(EventArgs e)  // Called to raise the event
    {
        if (Submit != null)
        {
            Submit(this, e);
        }
    }

    public void RaisePostBackEvent(string eventArgument)  // From IPostBackEventHandler
    {
        if (eventArgument == "DelayedSubmit")
        {
            OnSubmit(new EventArgs());
        }
    }

}

我的行为脚本看起来像这样:

DelayedSubmitBehavior = function(element) {
    DelayedSubmitBehavior.initializeBase(this, [element]);

    this._postBackEvent = null; // Stores the script required for the postback
}

DelayedSubmitBehavior.prototype = {
    // Delayed submit code removed for brevity, but normally this would be where 
    // initialize, dispose, and client-side event handlers would go

    // This is the client-side part of the PostBackEvent property
    get_PostBackEvent: function() {
        return this._postBackEvent;
    },
    set_PostBackEvent: function(value) {
        this._postBackEvent = value;
    }

    // This is the client-side event handler where the postback is initiated from
    _onTimerTick: function(sender, eventArgs) {
        // The following line evaluates the string var as javascript,
        // which will cause the desired postback
        eval(this._postBackEvent);
    }
}

现在,服务器端事件的处理方式与处理任何其他控件上的事件的方式相同.