Question

我对ASP.NET很新，但是我必须用VB创建一个.aspx表单，当从ddl中选择一个客户时，它将使用来自Access数据库的客户订单填充gridview。

到目前为止，我的问题是，当我尝试选择除第一个之外的任何其他客户时，gridview不会重新填充新信息。相反，它仍然停留在第一个客户的信息上。

这是我到目前为止所拥有的：

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="WebForm1.aspx.vb" Inherits="Technical_Challenge.WebForm1" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Technical Challenge</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <asp:Label ID="Label1" runat="server" Text="Customers"></asp:Label>
        <br />
        <asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1" DataTextField="CustomerName" DataValueField="CustomerID">
        </asp:DropDownList>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:TechChallengeConnectionString %>" ProviderName="<%$ ConnectionStrings:TechChallengeConnectionString.ProviderName %>" SelectCommand="SELECT [CustomerID], [CustomerName] FROM [Customers] ORDER BY [CustomerName]"></asp:SqlDataSource>
        <asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:TechChallengeConnectionString %>" ProviderName="<%$ ConnectionStrings:TechChallengeConnectionString.ProviderName %>" SelectCommand="SELECT * FROM [Orders] WHERE ([CustomerID] = ?)">
            <SelectParameters>
                <asp:ControlParameter ControlID="DropDownList1" Name="CustomerID" PropertyName="SelectedValue" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>

        <br />
        <asp:Label ID="CustomerOrdersLabel" runat="server" Text="Customer Orders">        </asp:Label>
        <br />
        <asp:GridView ID="GridView1" runat="server" AllowSorting="True" AutoGenerateColumns="False" CellPadding="4" DataKeyNames="OrderID" DataSourceID="SqlDataSource2" ForeColor="#333333" GridLines="None">
            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
            <Columns>
                <asp:BoundField DataField="OrderID" HeaderText="OrderID" InsertVisible="False" ReadOnly="True" SortExpression="OrderID" />
                <asp:BoundField DataField="CustomerID" HeaderText="CustomerID" SortExpression="CustomerID" />
                <asp:BoundField DataField="OrderPrice" HeaderText="OrderPrice" SortExpression="OrderPrice" />
            </Columns>
            <EditRowStyle BackColor="#999999" />
            <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
            <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
            <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
            <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
            <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
            <SortedAscendingCellStyle BackColor="#E9E7E2" />
            <SortedAscendingHeaderStyle BackColor="#506C8C" />
            <SortedDescendingCellStyle BackColor="#FFFDF8" />
            <SortedDescendingHeaderStyle BackColor="#6F8DAE" />
        </asp:GridView>

    </div>
    </form>
</body>
</html>

代码隐藏：

Public Class WebForm1
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

    Protected Sub SqlDataSource1_Selecting(sender As Object, e As SqlDataSourceSelectingEventArgs) Handles SqlDataSource1.Selecting

    End Sub
End Class

非常感谢任何帮助。谢谢！

Answer 1

我没有在下拉列表中看到AutoPostBack = True设置，或者发送数据进行处理的提交按钮？或者你还没有复制那段代码？

Answer 2

您必须按照以下方式对代码进行更改： -

.aspx更改： -

<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1" DataTextField="CustomerName" DataValueField="CustomerID" AutoPostBack="True">
</asp:DropDownList>

守则背后： -

Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged
     // write your query to select data from database 
    // bind with grid view
End Sub

ASP.NET / VB下拉列表未正确填充gridview

2 个答案: