Question

如何修复未设置为对象实例的＆＃34;对象引用＆＃34;错误。它指的是哪个对象？代码：

Private Sub dvSMasterCurrentYear_DataBound(sender As Object, e As EventArgs) Handles dvSMasterCurrentYear.DataBound
    Dim dv As DetailsView = New DetailsView
    If DetailsViewMode.Insert Then
        DirectCast(dv.FindControl("PlantYear"), TextBox).Text = GetYear()
    End If
End Sub

将年份返回到当前年份，它将显示在详细信息视图文本框中＆＃34; PlantYear＆＃34;。我尝试使用上面的代码插入值。

感谢您的帮助。

Answer 1

最有可能的FindControl实际上并没有找到控件。检查是否明智，以确保它实际上找到了您想要找到的内容：

Private Sub dvSMasterCurrentYear_DataBound(sender As Object, e As EventArgs) Handles dvSMasterCurrentYear.DataBound
    Dim dv As DetailsView = New DetailsView
    If DetailsViewMode.Insert Then
        Dim ctl = dv.FindControl("PlantYear")
        If ctl IsNot Nothing Then
            DirectCast(dv.FindControl("PlantYear"), TextBox).Text = GetYear()
        Else
            Throw New Exception("Control was not found")
        End If        
    End If
End Sub

当我尝试在asp.net Detailsview中添加一个值时，我得到一个＆＃34; Object引用未设置为对象的实例＆＃34;

1 个答案: