TargetInvocationException：调用的目标已引发异常。关于数据绑定答案

【问题标题】：TargetInvocationException: Exception has been thrown by the target of an invocation. on Data BindTargetInvocationException：调用的目标已引发异常。关于数据绑定
【发布时间】：2010-07-20 12:49:52
【问题描述】：

我正在尝试在 RowEditing 事件中将 GridView 绑定到数据源，但它会引发异常：

[TargetInvocationException: 调用目标抛出异常。] Eval()、XPath() 和 Bind() 等数据绑定方法只能在数据绑定控件的上下文中使用。

lblackout = EXMailbox.GetBlackouts();
BlackoutGridView.DataSource=lblackout;


protected void BlackoutGridView_RowEditing(object sender, GridViewEditEventArgs e)
{
        BlackoutGridView.EditIndex = e.NewEditIndex;
        BlackoutGridView.DataSource = lblackout;  //Throws exception here.
        BlackoutGridView.DataBind();
}


            <asp:GridView ID="BlackoutGridView" runat="server" AutoGenerateColumns="False" 
                OnRowDeleting="BlackoutGridView_RowDeleting" 
                OnRowEditing="BlackoutGridView_RowEditing" 
                onrowcancelingedit="BlackoutGridView_RowCancelingEdit">                            
                <Columns>
                    <asp:BoundField DataField="BlackoutId" HeaderText="BlackoutId" >
                    </asp:BoundField>
                    <asp:TemplateField HeaderText="Region">
                        <EditItemTemplate>
                        <asp:DropDownList ID="DropDownList11" runat="server" Text='<%# Bind("Region") %>' 
                                DataSourceID="lblackout" DataTextField="Region" DataValueField="Region"></asp:DropDownList>
                            <asp:ObjectDataSource ID="lblackout" runat="server" SelectMethod="GetDataItem" 
                                TypeName="Exchange.MailboxMove.WebUI.BlackoutScreen"></asp:ObjectDataSource>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="Label1" runat="server" Text='<%# Bind("Region") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField HeaderText="Server" DataField="Server">
                    </asp:BoundField>
                    <asp:BoundField HeaderText="From Date" DataField="StartDateTime" 
                        DataFormatString="{0:D}">
                    </asp:BoundField>
                    <asp:BoundField HeaderText="To Date" DataField="EndDateTime" 
                        DataFormatString="{0:D}">
                    </asp:BoundField>
                    <asp:BoundField HeaderText="From Time" DataField="StartDateTime" 
                        DataFormatString="{0:t}">
                    </asp:BoundField>
                    <asp:BoundField HeaderText="To Time" DataField="EndDateTime" 
                        DataFormatString="{0:t}">
                    </asp:BoundField>
                    <asp:CheckBoxField HeaderText="IsWeekly" DataField="IsWeekly">
                    </asp:CheckBoxField>
                    <asp:CommandField DeleteText="Cancel" HeaderText="Action" 
                        ShowDeleteButton="True" ShowEditButton="True" ShowHeader="True" >
                    </asp:CommandField>

【问题讨论】：

标签： c# asp.net gridview

【解决方案1】：

根据您的代码，我认为您错过了 Gridview 的 DataValue 字段。

这是来自 MSDN 的示例，如何绑定下拉列表

<asp:DropDownList ID="InsertCategoryDropDownList" 
                          DataSourceID="CategoriesDataSource"
                          DataTextField="CategoryName"
                          DataValueField="CategoryID"
                          RunAt="Server" />

没有 DataValue 字段，行编辑和其他事件将不会执行逻辑。我希望我对你有所帮助。您也可以签到MSDN For SqlDatasource http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.sqldatasource.aspx

【讨论】：