asp.net – 将服务器端事件添加到扩展程序控件

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.

所以现在我的扩展器控件的.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.