Dropdown list to attach to repeater that will filter gridview

问题

This post is similar to one I have posted before about a dropdown filtering results in a gridview. Well now I need this dropdown to attach itself to a repeater that will filter results into a gridview. I have tried rptLetters.DataBind() in the code behind of the dropdown list, but that doesn't seem to be changing any of the letters at the top of the page when I click on different items in the dropdown list.

The screenshot doesn't show enough of the products, but in this case it skips from G to L, and in the repeater the letters between G and L are still shown. I need to be able to get that repeater to recognize the letters that start each of the products associated with the company chosen.

<asp:Content ID="Content2" ContentPlaceHolderID="body" Runat="Server"><br /><br />
<asp:linkbutton id="btnAll" runat="server" text="ALL" onclick="btnAll_Click" />
<asp:repeater id="rptLetters" runat="server" datasourceid="dsLetters">
<headertemplate>
|
</headertemplate>
<itemtemplate>
<asp:linkbutton id="btnLetter" runat="server" onclick="btnLetter_Click"
text='<%#Eval("Letter")%>' />
</itemtemplate>

<separatortemplate>
|
</separatortemplate>
</asp:repeater>

<asp:sqldatasource id="dsLetters" runat="server" connectionstring="<%$
ConnectionStrings:ProductsConnectionString %>"
selectcommand="SELECT DISTINCT LEFT(ProductName, 1) AS [Letter] FROM [Product]">
</asp:sqldatasource>

<br /><br />Choose Company: 
<asp:DropDownList ID="ddlCompany" runat="server" AutoPostBack="true" 
 OnSelectedIndexChanged="ddlCompany_SelectedIndexChanged">
    <asp:ListItem Value="8">3rd Party</asp:ListItem>
    <asp:ListItem Value="4">BestDirect Securities</asp:ListItem>
    <asp:ListItem Value="18">Generic</asp:ListItem>
    <asp:ListItem Value="5">PFG Precious Metals</asp:ListItem>
    <asp:ListItem Value="1" Selected="True">PFGBest</asp:ListItem>
    <asp:ListItem Value="2">SFO</asp:ListItem>
    <asp:ListItem Value="6">Traders Press</asp:ListItem>
    <asp:ListItem Value="3">W&A Publishing</asp:ListItem>
</asp:DropDownList>
<asp:gridview id="gvProducts" runat="server" AutoGenerateColumns="False" 
    datakeynames="ProductID,CompanyID"  datasourceid="dsProductLookup" 
    style="margin-top: 12px;">
    <Columns>
        <asp:HyperLinkField DataNavigateUrlFields="ProductID" 
        DataNavigateUrlFormatString="Product/Default.aspx?ID={0}"
        DataTextField="ProductName" HeaderText="Product Name"
        SortExpression="ProductName" />
    </Columns>
 </asp:gridview>

<asp:sqldatasource id="dsProductLookup" runat="server" 
Connectionstring="<%$ ConnectionStrings:ProductsConnectionString %>"
SelectCommand="SELECT DISTINCT Product.ProductName, Product.ProductID, Company.CompanyID 
               FROM Product 
               LEFT JOIN CompanyLink 
               ON Product.ProductID = CompanyLink.ProductID 
               LEFT JOIN Company 
               ON CompanyLink.CompanyID = Company.CompanyID 
               ORDER BY Product.ProductName">
</asp:sqldatasource>

<asp:SqlDataSource ID="dsCompanyFilter" runat="server" 
    ConnectionString="<%$ ConnectionStrings:ProductsConnectionString %>" 
    SelectCommand="SELECT [CompanyName], [CompanyID] 
                   FROM [Company] 
                   ORDER BY CompanyName">
</asp:SqlDataSource>

</asp:Content>


Protected Sub btnAll_Click(sender As Object, e As EventArgs)
    gvProducts.DataBind()
End Sub

Protected Sub btnLetter_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim btnLetter As LinkButton = TryCast(sender, LinkButton)
    If btnLetter Is Nothing Then
        Return
    End If
    dsProductLookup.SelectCommand = [String].Format("SELECT ProductID, ProductName 
                                                     FROM [Product] 
                                                     WHERE ([ProductName] LIKE '{0}%')
                                                     ORDER BY [ProductName]", 
                                                     btnLetter.Text)

dsProductLookup.SelectParameters.Clear()

    Dim controlParam As ControlParameter = New ControlParameter
    controlParam.ControlID = "rptLetters"
    controlParam.DefaultValue = "-1"
    controlParam.Name = "CompanyID"
    controlParam.PropertyName = "Container.ItemIndex"
    controlParam.Type = TypeCode.String

    dsProductLookup.SelectParameters.Add(controlParam)
End Sub



Protected Sub ddlCompany_SelectedIndexChanged(ByVal sender As Object, ByVal e As 
System.EventArgs) Handles ddlCompany.SelectedIndexChanged
    rptLetters.DataBind()
    'SELECT statement to update letter repeater
    dsLetters.SelectCommand = "SELECT DISTINCT LEFT(ProductName, 1) AS [Letter] 
                               FROM Product, CompanyLink, Company 
                               WHERE Product.ProductID = CompanyLink.ProductID 
                               AND CompanyLink.CompanyID = Company.CompanyID 
                               AND Company.CompanyID = @CompanyID"

    dsLetters.SelectParameters.Clear()
    'declaring scalar variable @CompanyID
    Dim cp As ControlParameter = New ControlParameter
    cp.ControlID = "rptLetters"
    cp.DefaultValue = "-1"
    cp.Name = "CompanyID"
    cp.PropertyName = "SelectedValue"
    cp.Type = TypeCode.Int32

    dsLetters.SelectParameters.Add(cp)
    'SELECT statement to update Gridview based on dropdown list
    dsProductLookup.SelectCommand = "SELECT Company.CompanyName, Company.CompanyID,   
                                     Product.ProductName, Product.ProductID 
                                     FROM Company INNER JOIN CompanyLink 
                                     ON Company.CompanyID = CompanyLink.CompanyID 
                                     INNER JOIN Product 
                                     ON CompanyLink.ProductID = Product.ProductID
                                     WHERE Company.CompanyID = @CompanyID 
                                     ORDER BY Product.ProductName"

    dsProductLookup.SelectParameters.Clear()
    'declaring scalar variable @CompanyName
    Dim controlParam As ControlParameter = New ControlParameter
    controlParam.ControlID = "ddlCompany"
    controlParam.DefaultValue = "-1"
    controlParam.Name = "CompanyID"
    controlParam.PropertyName = "SelectedValue"
    controlParam.Type = TypeCode.Int32

    dsProductLookup.SelectParameters.Add(controlParam)

End Sub

UPDATE: Working code posted below. The repeater doesn't work like a regular control so I added a hidden dropdown list to do the dirty work for the repeater. Thanks for the help!

<asp:DropDownList ID="ddlLetters" runat="server" Visible="False"   DataSourceID="dsLetters">
</asp:DropDownList>
 Protected Sub ddlLetters_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
    rptLetters.DataBind()

    'SELECT statement to update letter repeater
    dsLetters.SelectCommand = "SELECT DISTINCT LEFT(ProductName, 1) AS [Letter] 
                              FROM Product, CompanyLink, Company 
                              WHERE Product.ProductID = CompanyLink.ProductID 
                              AND CompanyLink.CompanyID = Company.CompanyID 
                              AND Company.CompanyID = @CompanyID"

    'declaring scalar variable @CompanyID
    dsLetters.SelectParameters.Clear()
    Dim cp As ControlParameter = New ControlParameter
    cp.ControlID = "rptLetters"
    cp.DefaultValue = "-1"
    cp.Name = "CompanyID"
    cp.PropertyName = "ClientIDMode"
    cp.Type = TypeCode.Decimal
    dsLetters.SelectParameters.Add(cp)
End Sub

回答1:

I believe the issue is that you are not updating the dsLetters SelectCommand when the user selects a new company. Right now, it selects all products without taking the selected company into account. You should be able to modify the select command in ddlCompany_SelectedIndexChanged.

来源：https://stackoverflow.com/questions/7935135/dropdown-list-to-attach-to-repeater-that-will-filter-gridview