Question

我有一个gridview的用户控件，但由于某种原因我不能在后端代码中使用asp控件。在其他用户控件中我可以正常使用它们，但在这个特定的用户控件中，当我尝试使用gridview中使用的控件时，它会给出错误。这是我的gridview的代码，如果您发现异常，请告诉我：

<asp:GridView ID="gvGDG" runat="server" AutoGenerateColumns="False" 
    DataKeyNames="ID" DataSourceID="SqlDataSource1" Width="100%" CssClass="mGrid" GridLines="None" PagerStyle-CssClass="pgr" AlternatingRowStyle-CssClass="alt"
    AllowPaging="True" >
<AlternatingRowStyle CssClass="alt"></AlternatingRowStyle>
    <Columns>
        <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" 
            ItemStyle-HorizontalAlign="Center" CausesValidation="False">
        </asp:CommandField>
        <asp:BoundField DataField="ID" HeaderText="ID" 
            SortExpression="ID" InsertVisible="False" ReadOnly="True" 
            ItemStyle-HorizontalAlign="Center" >
        </asp:BoundField>      
        <asp:TemplateField HeaderText="Country" SortExpression="Country">
            <ItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Bind("Country") %>'></asp:Label>
            </ItemTemplate>
            <EditItemTemplate>
            <asp:UpdatePanel ID="countrypanel" runat="server">            
            <ContentTemplate>
            <asp:DropDownList ID="ddlCountry" runat="server" DataTextField="name" DataValueField="ID"  onselectedindexchanged="ddlcountry_SelectedIndexChanged" AppendDataBoundItems="true" AutoPostBack="true" />
            </ContentTemplate>
            <Triggers>
            <asp:AsyncPostBackTrigger ControlID="ddlCountry" />
            </Triggers>
            </asp:UpdatePanel>
            </EditItemTemplate>
            <ItemStyle HorizontalAlign="Center" />
        </asp:TemplateField>
        <asp:TemplateField HeaderText="State Province" SortExpression="State_Province">
            <ItemTemplate>
                <asp:Label ID="Label2" runat="server" Text='<%# Bind("State_Province") %>'></asp:Label>
            </ItemTemplate>
            <EditItemTemplate>
                             <asp:DropDownList ID="ddlState" runat="server" DataSourceID="SqlDataSource3" SelectedValue='<%# Bind("State_Province") %>'
                                 DataTextField="StateName" DataValueField="StateName">
                </asp:DropDownList>
                             <asp:SqlDataSource ID="SqlDataSource3" runat="server" 
                                 ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" 
                                 SelectCommand="SELECT [StateName] FROM [States]"></asp:SqlDataSource>
            </EditItemTemplate>
            <ItemStyle HorizontalAlign="Center" />
        </asp:TemplateField>
                <asp:TemplateField HeaderText="GDG Type" SortExpression="State_Province">
            <ItemTemplate>
                <asp:Label ID="Label3" runat="server" Text='<%# Bind("GDG_Type") %>'></asp:Label>
            </ItemTemplate>
            <EditItemTemplate>
                             <asp:DropDownList ID="ddlGdg" runat="server" DataSourceID="SqlDataSource4" SelectedValue='<%# Bind("GDG_Type") %>'
                                 DataTextField="GDG" DataValueField="GDG">
                </asp:DropDownList>
                             <asp:SqlDataSource ID="SqlDataSource4" runat="server" 
                                 ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" 
                                 SelectCommand="SELECT [GDG] FROM [GDG]"></asp:SqlDataSource>
            </EditItemTemplate>
            <ItemStyle HorizontalAlign="Center" />
        </asp:TemplateField>

          <asp:TemplateField HeaderText="Energy Type UOM" SortExpression="Energy_Type_UOM">
            <ItemTemplate>
                <asp:Label ID="Label4" runat="server" Text='<%# Bind("Energy_Type_UOM") %>'></asp:Label>
            </ItemTemplate>
            <EditItemTemplate>
                             <asp:DropDownList ID="ddlUomEnergy" runat="server" DataSourceID="SqlDataSource5" SelectedValue='<%# Bind("Energy_Type_UOM") %>'
                                 DataTextField="UOM" DataValueField="UOM">
                </asp:DropDownList>
                             <asp:SqlDataSource ID="SqlDataSource5" runat="server" 
                                 ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" 
                                 SelectCommand="SELECT UOM FROM UOM WHERE (Type = 'E')"></asp:SqlDataSource>
            </EditItemTemplate>
            <ItemStyle HorizontalAlign="Center" />
        </asp:TemplateField>


                      <asp:TemplateField HeaderText="GDG UOM" SortExpression="GDG_UOM">
            <ItemTemplate>
                <asp:Label ID="Label5" runat="server" Text='<%# Bind("GDG_UOM") %>'></asp:Label>
            </ItemTemplate>
            <EditItemTemplate>
                             <asp:DropDownList ID="ddlUom" runat="server" DataSourceID="SqlDataSource6" SelectedValue='<%# Bind("GDG_UOM") %>'
                                 DataTextField="UOM" DataValueField="UOM">
                </asp:DropDownList>
                             <asp:SqlDataSource ID="SqlDataSource6" runat="server" 
                                 ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" 
                                 SelectCommand="SELECT UOM FROM UOM WHERE (Type = 'O')"></asp:SqlDataSource>
            </EditItemTemplate>
            <ItemStyle HorizontalAlign="Center" />
        </asp:TemplateField>     
        <asp:BoundField DataField="GDG_Coeficient_Value" 
            HeaderText="GDG Coeficient Value" SortExpression="GDG Coeficient Value" 
            ItemStyle-HorizontalAlign="Center" >
<ItemStyle HorizontalAlign="Center"></ItemStyle>
        </asp:BoundField>
    </Columns>

<PagerStyle CssClass="pgr"></PagerStyle>
</asp:GridView>

提前致谢，Laziale

Answer 1

如果我那么。你有一个用户控件。说wucMyControl.ascx，你有一个gridview控件gvGDG。你无法从wucMyControl.ascx.cs访问它。如果出现问题，请使用以下解决方案：

在用户控件设计器文件中，检查Gridview控件的访问级别。可能会被改为私人，意外，而不是保护。如果是私有的，请将其保护或公开，并检查您是否能够立即访问它。

<强>更新仅供参考，您无法直接访问子控件。为此，您需要访问控件DataBound事件。

在你的情况下：

protected void GridView_RowDataBound(sender, e)
{
    if(e.Row.RowType == DataControlRowtype.DataRow)
     {
          var ddl = (DropdownList)e.Row.FindControl("ddlCountry");
          // do whatever you want with ddl. Similarly you can find all html and server control inside a gridview.
     }
}

这会对你有帮助......

将事件添加到gridview子控件

在GridView1_RowDataBound方法中，通过调用ddl.SelectedIndexChanged += new EventHandler(ddl_SelectedIndexChanged);

创建下拉列表时添加处理程序

然后，声明void ddl_SelectedIndexChanged(object sender, EventArgs e)方法来处理您的逻辑。 sender参数将是对所选下拉列表的引用。同时将drodownlist的AutoPostback属性设置为true。

Answer 2

我想也许你在ASP.net设计师页面顶部的代码有些错误：

请查看CodeFile =“??????”和继承=“????????”

无法从gridview访问asp控件

2 个答案: