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我似乎无法弄清楚我在哪里出错了。我有两个列表框，第一个从 sql 服务器上的存储过程中提取数据。the second list box is supposed to populate when the an item in the first list box is selected. 当单击第一个列表框中的项目时，第二个列表框的存储过程应传递所选项目的文本。问题是第二个列表框没有填充。我将不胜感激任何有用的反馈，或者可能是一种更简单的方法来完成我正在尝试做的事情。

ASP.NET：

<asp:ListBox ID="ListBox1" runat="server" DataSourceID="LOCATION" DataTextField="L_Name" DataValueField="L_Name" AutoPostBack="True"></asp:ListBox>

<asp:SqlDataSource ID="LOCATION" runat="server" ConnectionString="<%$ ConnectionStrings:SAMC_2ConnectionString %>" SelectCommand="L_Get" SelectCommandType="StoredProcedure"></asp:SqlDataSource>

<asp:ListBox ID="ListBox2" runat="server" Height="150px" Width="200px" AutoPostBack="True" DataTextField="C_Name" DataValueField="C_Name" />

<asp:SqlDataSource ID="CompByLocal" runat="server" ConnectionString="<%$ ConnectionStrings:SAMC_2ConnectionString %>" SelectCommand="L_Get_C" SelectCommandType="StoredProcedure">    

<SelectParameters>
<asp:ControlParameter ControlID="ListBox1" DefaultValue="" Name="L_Name" PropertyName="SelectedValue" Type="String" />
<asp:Parameter Name="L_ID" Type="Int32" />
        </SelectParameters>
    </asp:SqlDataSource>

VB.NET：

Protected Sub ListBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        Dim val As String = ListBox1.Items(ListBox1.SelectedIndex).ToString
        TextBox1.Text = val
        ListBox2.Items.Clear()
        ListBox2.DataSource = CompByLocal
        ListBox2.DataBind()
    End Sub
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1 回答 1

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我的建议是放弃 SqlDataSources 并在后端完成所有操作 - 然后您可以更准确地了解我的经验何时发生事情。我已尽力在下面编写必要的代码，但我的母语是 C# - 我使用了在线转换器，所以请原谅任何小的语法错误。

ASPX：

<asp:ListBox  ID="ListBox1" runat="server"  DataTextField="L_Name" DataValueField="L_Name" AutoPostBack="True"></asp:ListBox>

<asp:ListBox ID="ListBox2" runat="server" Height="150px" Width="200px" AutoPostBack="True" DataTextField="C_Name" DataValueField="C_Name" />

.VB

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) 
if (IsPostback) return
Dim results As New DataTable()
Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("SAMC_2ConnectionString "))
    connection.Open()
    Using command As New SqlCommand("L_Get", connection)
        command.CommandType = CommandType.StoredProcedure
        results.Load(command.ExecuteReader())
    End Using
End Using
ListBox1.DataSource = results;
ListBox1.DataBind();
End Sub


Protected Sub ListBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) 
Dim results As New DataTable()
Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("SAMC_2ConnectionString "))
    connection.Open()
    Using command As New SqlCommand("L_Get_C", connection)
        command.CommandType = CommandType.StoredProcedure
        command.Parameters.AddWithValue("L_ID",ListBox1.SelectedValue)
        results.Load(command.ExecuteReader())
    End Using
End Using
ListBox2.DataSource = results
ListBox2.DataBind()
End Sub
于 2013-02-15T22:33:08.980 回答