Question

我试图更改formview中标签中的文字。理论上，当用户单击按钮时，这应该转到SQL表，提取数据，并将新文本输入到名为Description的标签中。这是数据绑定所以我怀疑这是我的问题的一部分，因为我收到错误消息＆＃34;对象引用未设置为对象的实例。＆＃34;

下面是asp部分（对不起，但它不会像在asp中输入的那样完全显示）：

td class =＆＃34; style29＆＃34;列跨度=＆＃34; 4＆＃34; style =＆＃34; border：1px solid＃000000＆＃34;＆gt; strong＆gt;说明：/ strong＆gt;

asp：标签ID =＆＃34; DescriptionLabel＆＃34; RUNAT =＆＃34;服务器＆＃34; 文字=＆＃39;＆lt;％＃Bind（＆＃34;说明＆＃34;）％＆gt;＆＃39;宽度=＆＃34; 1000像素＆＃34;

下面是VB代码：

Protected Sub Button1_Click(sender As Object, e As System.EventArgs) Handles Button1.Click
    Dim conCString1 As String = ConfigurationManager.ConnectionStrings("conCString1").ConnectionString
    Dim sqlConnection1 As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("conCString1").ConnectionString)
    Dim cmd1 As New SqlCommand
    cmd1.CommandType = CommandType.Text
    cmd1.Connection = sqlConnection1

    Dim querystring1 As String = "SELECT [Rule] FROM [BuildRules] WHERE ([Table] = N'Capacitors') AND (Field = N'Description')"
    sqlConnection1.Open()
    Dim command2 As New SqlCommand(querystring1, sqlConnection1)
    Dim reader2 As SqlDataReader = command2.ExecuteReader()
    Dim lblD As Label = FormView1.FindControl("DescriptionLabel")

    While reader2.Read()
        'below is test line only
        lblD.Text = reader2(0) 'Example: 'CAP', Value, Dielectric Type, Package Size, Rated Voltage, Tolerance, Temperature Coefficient


    End While
    sqlConnection1.Close()

End Sub

Answer 1

我不认为你的'FindControl'工作正常。试试这个：

  Dim lblD As Label = DirectCast(FindName("DescriptionLabel"), Label)

看看是否有效。

更改formview数据绑定标签文本

1 个答案: