DataGrid ItemDataBound 干扰 DropDownList SelectedIndexChanged 事件

Question

我有一个带有 DataGrid 的 ASP.Net 4.6.1 网页。在DataGrid 的一个TemplateColumn 中，我有一个DropDownList。 DropDownList 有一个 OnSelectedIndexChanged 事件处理程序：

<asp:DataGrid runat="server" ID="dgPartnerApprovalPending" DataKeyField="OrderID" 
                       CellPadding="10" CellSpacing="10" AlternatingItemStyle-BackColor="WhiteSmoke" HeaderStyle-BackColor="WhiteSmoke" AutoGenerateColumns="false" 
                        AllowSorting="true" OnSortCommand="dgPartnerApprovalPending_SortCommand">
                        <Columns>
                            <asp:BoundColumn DataField="AttorneyName" HeaderText="Attorney Name" SortExpression="AttorneyName" />
                            <asp:BoundColumn DataField="Title" HeaderText="Title" SortExpression="Title" />
                            <asp:BoundColumn DataField="Description" HeaderText="Description" SortExpression="Description" />
                            <asp:BoundColumn DataField="RequestDate" HeaderText="Request Date" SortExpression="RequestDate" />
                            <asp:BoundColumn DataField="TotalAmount" HeaderText="Total Amount" SortExpression="TotalAmount" />
                            <asp:BoundColumn DataField="OrderStatus" HeaderText="Order Status" SortExpression="OrderStatus" />
                            <asp:TemplateColumn HeaderText="Status">
                                <ItemTemplate>
                                    <asp:DropDownList runat="server" ID="ddlStatus" OnSelectedIndexChanged="ddlStatus_SelectedIndexChanged" AutoPostBack="true" 
                                        DataSourceID="sdsStatuses" DataTextField="OrderStatus" DataValueField="OrderStatusID" /> 
                                </ItemTemplate>
                            </asp:TemplateColumn>
                            <asp:BoundColumn DataField="OrderID" HeaderText="Order ID" SortExpression="OrderID" />
                            <asp:HyperLinkColumn Text="Files" DataNavigateUrlField="OrderID" DataNavigateUrlFormatString="~/Files/{0}" />
                        </Columns>
                    </asp:DataGrid>

OnSelectedIndexChanged 事件处理程序工作正常，直到我将 OnItemDataBound 事件处理程序添加到 DataGrid：

<asp:DataGrid runat="server" ID="dgPartnerApprovalPending" DataKeyField="OrderID" OnItemDataBound="dgPartnerApprovalPending_ItemDataBound" 
                       CellPadding="10" CellSpacing="10" AlternatingItemStyle-BackColor="WhiteSmoke" HeaderStyle-BackColor="WhiteSmoke" AutoGenerateColumns="false" 
                        AllowSorting="true" OnSortCommand="dgPartnerApprovalPending_SortCommand">
                        <Columns>
                            <asp:BoundColumn DataField="AttorneyName" HeaderText="Attorney Name" SortExpression="AttorneyName" />
                            <asp:BoundColumn DataField="Title" HeaderText="Title" SortExpression="Title" />
                            <asp:BoundColumn DataField="Description" HeaderText="Description" SortExpression="Description" />
                            <asp:BoundColumn DataField="RequestDate" HeaderText="Request Date" SortExpression="RequestDate" />
                            <asp:BoundColumn DataField="TotalAmount" HeaderText="Total Amount" SortExpression="TotalAmount" />
                            <asp:BoundColumn DataField="OrderStatus" HeaderText="Order Status" SortExpression="OrderStatus" />
                            <asp:TemplateColumn HeaderText="Status">
                                <ItemTemplate>
                                    <asp:DropDownList runat="server" ID="ddlStatus" OnSelectedIndexChanged="ddlStatus_SelectedIndexChanged" AutoPostBack="true" 
                                        DataSourceID="sdsStatuses" DataTextField="OrderStatus" DataValueField="OrderStatusID" /> 
                                </ItemTemplate>
                            </asp:TemplateColumn>
                            <asp:BoundColumn DataField="OrderID" HeaderText="Order ID" SortExpression="OrderID" />
                            <asp:HyperLinkColumn Text="Files" DataNavigateUrlField="OrderID" DataNavigateUrlFormatString="~/Files/{0}" />
                        </Columns>
                    </asp:DataGrid>

下面是触发 ItemDataBound 事件时调用的代码：

protected void dgPartnerApprovalPending_ItemDataBound(object sender, DataGridItemEventArgs e)
    {
        ListItemType itemType = (ListItemType)e.Item.ItemType;           

        if (itemType == ListItemType.Item || itemType == ListItemType.AlternatingItem)
        {
            DataRowView view = (DataRowView)e.Item.DataItem;
            string OrderID = view["OrderID"].ToString();

            for (int i = 0; i <= 6; i++)
            {
                e.Item.Cells[i].Attributes.Add("OnClick", "window.location.href='PartnerApprovalDetail.aspx?oid="
                + OrderID
                + "'"
                );
            }
        }
    }

简而言之，ItemDataBound 事件使每一行都可点击，并将用户重定向到不同的页面。添加此事件处理程序并加载页面后，每当我单击任何行中的 DropDownList 时，页面都会变为空白。如果我在调试器中执行此操作，则永远不会触发 SelectedIndexChanged 事件。在使行可单击后，我尝试将数据绑定到 OnItemDataBound 处理程序中的 DropDownList。我还尝试在 PostBack 之后将数据绑定到 PageLoad() 中的 DropDownList。两者都没有帮助。我该如何解决这个问题？

Answer 1

您正在表格单元格<td> 添加 onclick 事件处理程序，并且下拉列表呈现在表格单元格内。因此，当您尝试单击下拉菜单时，单击事件被父表格单元格中定义的事件处理程序捕获将用户带走的级别。

您可以创建一个新的模板列来呈现详细信息链接：

    <asp:TemplateColumn HeaderText="Status">
       <ItemTemplate>
          <asp:HyperLink ID="DetailsUrls" runat="server" href="PartnerApprovalDetail.aspx?oid=<%#Eval("OrderID")%>">Detail</asp:HyperLink>
      </ItemTemplate>
    </asp:TemplateColumn>