从 ListView 中删除项目

Question

我正在尝试做一个 ASP.NET 应用程序。我正在使用我在 .aspx 文件中的 ListView 中设置为 DataSource 的 DataSet。问题是当我单击删除按钮时似乎没有任何反应，但是当我刷新浏览器时，我收到如下错误消息：

"要重新显示网页，网络浏览器需要重新发送 您之前提交的信息。”

我真的试图弄清楚我做错了什么或可能导致这种情况的原因。这是我的 C# 代码：

namespace WebApplication1
{
    public partial class _Default : Page
    {

        DataSet orderDetails;

        protected void Page_Load(object sender, EventArgs e)
        {

            Message.Text = "";

            string orderPath = AppDomain.CurrentDomain.BaseDirectory + "/App_Data/orders.xml";
            string orderSchemaPath = AppDomain.CurrentDomain.BaseDirectory + "/App_Data/orderschema.xsd";

            XDocument document = XDocument.Load(orderPath);
            XmlSchemaSet schemas = new XmlSchemaSet();
            schemas.Add("", XmlReader.Create(orderSchemaPath));
            bool errors = false;

            document.Validate(schemas, (o, err) =>
            {
                System.Diagnostics.Debug.WriteLine("Validation error: {0}", err.Message);
                errors = true;
            });

            if (!errors)
            {
                System.Diagnostics.Debug.WriteLine("XML document successfully validated.");

                try
                {
                    orderDetails = new DataSet();
                    orderDetails.ReadXml(orderPath);

                    listViewOrders.DataSource = orderDetails;
                    listViewOrders.DataBind();
                }

                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine("Error: " + ex);
                }

            }
            else
            {
                System.Diagnostics.Debug.WriteLine("XML document does not validate.");
            }
            System.Diagnostics.Debug.WriteLine("Page_load done");
        }

        void BindData()
        {
            listViewOrders.DataSource = orderDetails;
            listViewOrders.DataBind();
        }

        //Call databind method in your prerender event
        protected void Page_PreRender(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                BindData();
            }
        }

        protected void OrderListView_ItemCommand(object sender, ListViewCommandEventArgs e)
        {
            if (e.CommandName == "Delete")
            {
                listViewOrders.DeleteItem(e.Item.DataItemIndex);
                BindData();
            }
        }

        protected void OrdersListView_ItemDeleted(object sender, ListViewDeletedEventArgs e)
        {
            //Check if an exception occurred to display an error message.
            if (e.Exception != null)
            {
                Message.Text = "An exception occurred deleting the contact.";
                e.ExceptionHandled = true;
            }
            else
            {
                // Clear the selected index.
                listViewOrders.SelectedIndex = -1;
            }
        }

        protected void OrdersListView_OnItemDeleting(object sender, ListViewDeleteEventArgs e)
        {


        }

    }
}

这是我的 .aspx 文件中的 ListView：

        <asp:ListView ID="listViewOrders"
        DataKeyNames="orderid"
        runat="server"
        OnItemDeleting="OrdersListView_OnItemDeleting"
        OnItemCommand="OrderListView_ItemCommand">
        <LayoutTemplate>
            <table cellpadding="2" width="640px" border="1" runat="server" id="tblProducts">
                <tr runat="server">
                    <th runat="server">Order person</th>
                    <th runat="server">Order ID</th>
                    <th runat="server">Delete</th>
                </tr>
                <tr runat="server" id="itemPlaceholder" />
            </table>
        </LayoutTemplate>
        <ItemTemplate>
            <tr runat="server">
                <td>
                    <asp:Label ID="FirstNameLabel" runat="Server" Text='<%#Eval("orderperson") %>' />
                </td>
                <td valign="top">
                    <asp:Label ID="LastNameLabel" runat="Server" Text='<%#Eval("orderid") %>' />
                </td>
                <td>
                    <asp:LinkButton ID="DeleteButton" runat="Server" class="glyphicon glyphicon-remove" CommandName="Delete" CommandArgument="X"  />
                </td>
            </tr>
        </ItemTemplate>
        <EditItemTemplate>
            <tr style="background-color: #ADD8E6">
                <td>
                    <asp:LinkButton ID="UpdateButton" runat="server" CommandName="Update" Text="Update" />&nbsp;
          <asp:LinkButton ID="CancelButton" runat="server" CommandName="Cancel" Text="Cancel" />
                </td>
                <td>
                    <asp:TextBox ID="FirstNameTextBox" runat="server" Text='<%#Bind("orderperson") %>'
                        MaxLength="50" /><br />
                </td>
                <td>
                    <asp:TextBox ID="LastNameTextBox" runat="server" Text='<%#Bind("orderid") %>'
                        MaxLength="50" /><br />
                </td>
            </tr>
        </EditItemTemplate>
    </asp:ListView>

Answer 1

当您使用 listView 命令时，您必须更新面板。

将您的 listView 放在这样的 asp:panel 中

 <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
    <ContentTemplate>
       ... your list View Code
    </ContentTemplate>
 </asp:UpdatePanel>

在 DataBind 之后，您必须通过

更新面板

UpdatePanel1.Update();