添加事件委托

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AddHandler xdlstFriends.EditCommand, AddressOf xdlstFriends_ItemCommand

内层控件数据绑定与事件声明在外层的ItemDataBind中实现;例子中外层DataList的Id为dlQuestion,内层为dlItem;代码如下

private void dlQuestion_ItemDataBound(object sender, System.Web.UI.WebControls.DataListItemEventArgs e)
        {

            if ( e.Item.ItemType == ListItemType.EditItem || e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem )
            {
                LinkButton lb = (LinkButton)e.Item.FindControl("lbtnDelete");
                if ( lb != null )
                    lb.Attributes.Add("onclick", "return confirm('确实要删除么?')");
                 //得到内层DataList
                DataList dlItem= (DataList)e.Item.FindControl("repItem");
                if ( dlItem != null )
                {
                    if ( ViewState["repIndex"] != null )
                    {
                       dlItem.EditItemIndex = (int ) ViewState["repIndex"];
                    }
                    dlItem .ItemCommand += new DataListCommandEventHandler(dlItem_ItemCommand);

                    dlItem .ItemDataBound += new DataListItemEventHandler(dlItem_ItemDataBound);

                    int qid = ((InvQuestion)e.Item.DataItem).Que_Id;
                    ArrayList al = InvController.GetItemCollection( qid );
                    dlItem .DataSource = al;
                    dlItem .DataBind();
                }

            }

        }
其中ViewState对状态信息的读取和下面的保存联系后再讨论;

下面以内层DataList的Edit事件为例;

private void dlItem_ItemCommand(object source, DataListCommandEventArgs e)
        {
            if ( e.CommandName == "edit")
            {
                int qid = 0;
                //得到外层datalist
                DataList dllist = (DataList)e.Item.Parent.Parent.Parent;
                                //取得外层Question记录的Id
                HtmlInputHidden lbEditNum = (HtmlInputHidden)dllist.Items[0].FindControl("hidQuestion");


                if ( lbEditNum.Value != "")
                {
                    qid = int.Parse(lbEditNum.Value);
                }

                                //得到内层DataList
                DataList dl = (DataList)e.Item.Parent;
                dl.EditItemIndex = e.Item.ItemIndex;
                //保存状态信息
                ViewState["repIndex"] = e.Item.ItemIndex;
                // Response.Write(e.Item.ItemIndex);

                                //重新绑定内层DataList数据
                ArrayList al = InvController.GetItemCollection( qid );
                dl.DataSource = al;
                dl.DataBind();
            }
}
在内层DataList中e.CommandName="edit"事件中必须保存ViewState["index"] = e.Item.Index信息;否则在e.CommandName="update"中得不到editIndex的信息.需要保存ViewState的原因是:由于暂时没有找到更好的方法,内层DataList数据绑定需要在每个事件发生时对外层DataList重新绑定,也就是在Page.Load中加载DataBind()事件,对效率有一定影响