c# - 在 ListView 的下拉列表中获取 selectedIndexChanged 上的 ListView 项的值

Question

我在该 ListView 的每一行中都有一个 ListView 和 DropDownList。您可以在该 DropDownlist 中更改指定人员(DropDownList 显示来自 MySql 数据库的数据)。

换人的时候需要做一些数据库操作。为此，我需要知道人员在哪个 ListView 行上发生了更改，并且我需要知道该条目的值。

这是我的 aspx 文件:

<asp:ListView ID="manageAssigneesListView" runat="server" DataKeyNames="" OnItemDataBound="OnDataBound">            
                <ItemTemplate>
                    <div class="summaryRow">
                        <asp:Label ID="customerId" runat="server"><%# Eval("customerId") %>&nbsp;</asp:Label>    
                        <div style="width:200px; margin: 0px 5px; float: left;"><%# Eval("lastName") %>, <%# Eval("firstName") %></div>
                        <div style="width:120px; margin: 0px 2px; float: left;">Nr.</div>
                        <div style="width:200px; margin-left: 50px; float: right;">
                            <asp:DropDownList runat="server" ID="selectAssignee" Width="196" AppendDataBoundItems="true" OnSelectedIndexChanged="selectAssignee_OnSelectedIndexChanged" AutoPostBack="true">
                            </asp:DropDownList>
                        </div>
                        <div class="clear"></div>
                    </div>
                </ItemTemplate>
            </asp:ListView>   

这是我的代码隐藏:

protected void Page_Load(object sender, EventArgs e)
    {
        Helper.doAuth(Session, Response);

        if (!IsPostBack)
        {
            // load all customers without assignee
            MySqlCommand cmd = new MySqlCommand();
            MySqlConnection con = new MySqlConnection();
            con.ConnectionString = Helper.CONNECTION_STRING;
            cmd.CommandText = "SELECT customerId, lastName, firstName, assignee FROM customer WHERE assignee IS NULL ORDER BY customerId DESC";
            cmd.Connection = con;
            con.Open();
            MySqlDataAdapter sda = new MySqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            sda.Fill(ds);
            manageAssigneesListView.DataSource = ds;
            manageAssigneesListView.DataBind();
            con.Close();

        }
    }

    protected void OnDataBound(object sender, ListViewItemEventArgs e)
    {
        DropDownList selectAssignee = (e.Item.FindControl("selectAssignee") as DropDownList);

        MySqlCommand cmd = new MySqlCommand();
        MySqlConnection con = new MySqlConnection();
        con.ConnectionString = Helper.CONNECTION_STRING;
        cmd.CommandText = "SELECT * FROM user where role = " + Helper.ROLE_SALESPERSON;
        cmd.Connection = con;
        con.Open();
        MySqlDataAdapter sda = new MySqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        sda.Fill(ds);
        selectAssignee.DataSource = ds;
        selectAssignee.DataTextField = "emailAdress";
        selectAssignee.DataBind();
        con.Close();    
    }


    protected void selectAssignee_OnSelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList dropDownList = (DropDownList)sender;
        ListViewItem listView = (ListViewItem)dropDownList.NamingContainer;

        var test = listView.DataItem;
        string test2 = listView.FindControl("customerId").ToString();

        int rowIndex = (int)listView.DataItemIndex;
        Label lblMessage = (Label)listView.FindControl("customerId");
    }

我成功获取了行的 DataItemIndex 我更改了 DropDownList 的值，而且 DropDownlist 正在触发正确的 onSelectedIndexChanged，但我需要的是标签“customerId”的值，我不知道如何获取这个值。

提前致谢

Answer 1

您需要使用 FindControl 获取对 Label 的引用，然后使用它的 Text 属性:

ListViewItem item = (ListViewItem)dropDownList.NamingContainer;
Label lbltCustomerID = (Label) item.FindControl("customerId");
string customerID = lblCustomerID.Text;

顺便说一句，ListViewItem.DataItem 在回发时始终为 null。

编辑:

你应该设置标签的Text，而不是

<asp:Label ID="customerId" runat="server">
    <%# Eval("customerId") %>&nbsp;
</asp:Label>    

这个

<asp:Label ID="customerId" runat="server"
   Text='<%# Eval("customerId") %>' >
</asp:Label>