SQLDataSource内部GridView

Question

在过去的几天里，我一直试图为我的问题找到一个解决方案，但到目前为止我还没有。我有一个Gridview，在编辑模式下，其中一个字段有一个人员的DropDownList，它由一个选择填充，该选择使用该行的另外两个字段(State和City)。我尝试了我在网络上找到的所有关于它的东西，但我无法使它发挥作用。你能帮帮我吗？代码如下

<asp:GridView ID="GridView1" runat="server" AllowSorting="True"  
        DataKeyNames="id,Municipio,UF" DataSourceID="SqlDataSource5">
        <AlternatingRowStyle BackColor="White" />
        <Columns>
            <asp:CommandField ShowEditButton="True" />
            ...stuff...
            <asp:TemplateField HeaderText="UF" SortExpression="UF">
                <EditItemTemplate>
                    <asp:Label ID="Label1" runat="server" Text='<%# Eval("UF") %>'>
                    </asp:Label>
                </EditItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="Label1" runat="server" Text='<%# Bind("UF") %>'>
                    </asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Municipio" SortExpression="Municipio">
                <EditItemTemplate>
                    <asp:Label ID="Label2" runat="server" Text='<%# Eval("Municipio") %>'></asp:Label>
                </EditItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="Label2" runat="server" Text='<%# Bind("Municipio") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="People" SortExpression="People">
                <ItemTemplate>
                    <asp:Label ID="LbPeople" runat="server" Text='<%# Bind("Cultura") %>'></asp:Label>
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:DropDownList ID="DdlPeople" runat="server" AutoPostBack="true" 
                        DataSourceID="SqlDataSourcePeopleEdit" DataTextField="People" 
                        DataValueField="People">
                    </asp:DropDownList>
                    <asp:HiddenField ID="Hidden1" Value='<%# Bind("Municipio") %>' runat="server"/>
                    <asp:HiddenField ID="Hidden2" Value='<%# Bind("UF") %>' runat="server"/>
                    <asp:SqlDataSource ID="SqlDataSourcePeopleEdit" runat="server" 
                        ConnectionString="<%$ ConnectionStrings:dbdb %>" 
                        ProviderName="<%$ ConnectionStrings:somar.ProviderName %>"
                        SelectCommand="SELECT People FROM Table_People WHERE (Cidade = @Municipio) AND (UF = @UF)"
                        CancelSelectOnNullParameter="false">
                        <SelectParameters>
                            <asp:ControlParameter ControlID="Hidden1" Name="Municipio" PropertyName="Value" Type="String" />
                            <asp:ControlParameter ControlID="Hidden2" Name="UF"        PropertyName="Value" Type="String" />
                        </SelectParameters>
                    </asp:SqlDataSource>
                </EditItemTemplate>
            </asp:TemplateField>
       ...stuff...     
    </asp:GridView>

我做错什么了？

当我单击“编辑”更新时，下拉列表不会加载值。如果我在CancelSelectOnNullParameter=上设置属性SqlDataSource“false”，它显示‘必须声明标量变量@xxx’，我检查了隐藏字段，并且它们加载了值，因此问题是控件参数taht没有从它获得值。

Answer 1

您应该做的是在下拉列表之前拥有隐藏字段和sqldatasource。您所遇到的问题是由于加载数据时造成的。

<asp:GridView ID="GridView1" runat="server" AllowSorting="True"  
    DataKeyNames="id,Municipio,UF" DataSourceID="SqlDataSource5">
    <AlternatingRowStyle BackColor="White" />
    <Columns>
        <asp:CommandField ShowEditButton="True" />
        ...stuff...
        <asp:TemplateField HeaderText="UF" SortExpression="UF">
            <EditItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Eval("UF") %>'>
                </asp:Label>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Bind("UF") %>'>
                </asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Municipio" SortExpression="Municipio">
            <EditItemTemplate>
                <asp:Label ID="Label2" runat="server" Text='<%# Eval("Municipio") %>'></asp:Label>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="Label2" runat="server" Text='<%# Bind("Municipio") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="People" SortExpression="People">
            <ItemTemplate>
                <asp:Label ID="LbPeople" runat="server" Text='<%# Bind("Cultura") %>'></asp:Label>
            </ItemTemplate>
            <EditItemTemplate>
                <asp:HiddenField ID="Hidden1" Value='<%# Bind("Municipio") %>' runat="server"/>
                <asp:HiddenField ID="Hidden2" Value='<%# Bind("UF") %>' runat="server"/>
                <asp:SqlDataSource ID="SqlDataSourcePeopleEdit" runat="server" 
                    ConnectionString="<%$ ConnectionStrings:dbdb %>" 
                    ProviderName="<%$ ConnectionStrings:somar.ProviderName %>"
                    SelectCommand="SELECT People FROM Table_People WHERE (Cidade = @Municipio) AND (UF = @UF)"
                    CancelSelectOnNullParameter="false">
                    <SelectParameters>
                        <asp:ControlParameter ControlID="Hidden1" Name="Municipio" PropertyName="Value" Type="String" />
                        <asp:ControlParameter ControlID="Hidden2" Name="UF"        PropertyName="Value" Type="String" />
                    </SelectParameters>
                </asp:SqlDataSource>

                <asp:DropDownList ID="DdlPeople" runat="server" AutoPostBack="true" 
                    DataSourceID="SqlDataSourcePeopleEdit" DataTextField="People" 
                    DataValueField="People">
                </asp:DropDownList>
            </EditItemTemplate>
        </asp:TemplateField>
   ...stuff...     
</asp:GridView>