asp.net - 如何处理 Null(GridView Container.DataItem)

Question

这里有什么问题，为什么它会提示关闭 ")" ？

<asp:TemplateField HeaderText="Name" SortExpression="Name">
                    <ItemTemplate>   
                        <%# FixNull((namespace.Student)(Container.DataItem), "Name"); %>               
                    </ItemTemplate>
                    <EditItemTemplate>
                       <asp:dropdownlist id="ddlStudent" runat="server" datasourceid="CountyDataSource"
                            datatextfield="Name" datavaluefield="Id" autopostback="false">
                        </asp:dropdownlist>
                    </EditItemTemplate>
                </asp:TemplateField>

 protected string FixNull(object dataItem, string fieldName)
 {
        if (dataItem != null)
        {
            System.Data.DataRowView cls = (System.Data.DataRowView)dataItem;
            if (!cls.Row.IsNull(fieldName))
                return (cls[fieldName]).ToString();
            else
                return "&nbsp;";
        }
        else
            return "&nbsp;";
    }



Compiler Error Message: CS1026: ) expected

Source Error: Line: 133 


Line 131:                  <asp:TemplateField HeaderText="Name" SortExpression="Name">
Line 132:                    <ItemTemplate>   
Line 133:    <%# FixNull((namespace.Student)(Container.DataItem), "Name"); %>               
Line 134:                    </ItemTemplate>
Line 135:                    <EditItemTemplate>

Answer 1

<%# Eval("CountyName") == null ? "&nbsp;" : Eval("CountyName")%>