高手帮我看看这是怎么回事，老是说重载和委托不匹配

Question

<asp:DetailsView ID="DetailsView1" runat="server" Height="50px" Width="100%" AutoGenerateRows="false" 
                OnModeChanging="DetailsView1_ModeChanging" Style="text-align: left" OnItemInserting ="DetailsView1_ItemInserting" 
                OnItemUpdating="DetailsView1_ItemUpdating"> 
                <HeaderTemplate> 
                    用户详细信息 
                </HeaderTemplate> 
                <Fields> 
                    <asp:BoundField DataField="id" HeaderText="ID号" InsertVisible="false" ReadOnly="true" /> 
                    <asp:BoundField DataField="Username" HeaderText="用户名" /> 
                    <asp:BoundField DataField="Userpwd" HeaderText="密码" /> 
                    <asp:CommandField ShowInsertButton="true" /> 
                    <asp:CommandField ShowEditButton="true" /> 
                </Fields> 
                <HeaderStyle BackColor="#E0F2FF" Font-Bold="true" ForeColor="Teal" /> 
            </asp:DetailsView> 
protected void DetailsView1_ItemInserting(object sender, DetailsViewInsertedEventArgs e) 
    { 
        //获取要插入的信息 
        string user_name = ((TextBox)DetailsView1.Rows[1].Cells[1].Controls[0]).Text.ToString(); 
        string user_password = ((TextBox)DetailsView1.Rows[2].Cells[1].Controls[0]).Text.ToString(); 
        userlogin.InsertBindDetailView(user_name,user_password); 
        MainQuery(""); 
        //修改DetailsView1的模式为只读模式 
        DetailsView1.ChangeMode(DetailsViewMode.ReadOnly); 
        //调用BindDetailView()函数重新绑定 
        BindDetailView(ViewState["id"].ToString()); 
    }     /// <summary> 
    /// 单击更新按钮事件 
    /// </summary> 
    /// <param name="sender"> </param> 
    /// <param name="e"> </param> 
    protected void DetailsView1_ItemUpdating(object sender, DetailsViewUpdatedEventArgs e) 
    { 
        //获取要更新的信息 
        string user_name = ((TextBox)DetailsView1.Rows[1].Cells[1].Controls[0]).Text.ToString(); 
        string user_password = ((TextBox)DetailsView1.Rows[2].Cells[1].Controls[0]).Text.ToString(); 
        userlogin.UpdateBindDetailView(user_name, user_password); 
        MainQuery(""); 
        //修改DetailsView1的模式为只读模式 
        DetailsView1.ChangeMode(DetailsViewMode.ReadOnly); 
        //调用BindDetailView()函数重新绑定 
        BindDetailView(ViewState["id"].ToString()); 
    }