Question

基本上，我已经遇到过这个错误很多次并尝试修复它，但无济于事。我已经四处看看，似乎没有一个解决方案对我有所帮助。我尝试做的是用Access数据库中的数据填充标签。但是，它只会填充7个必填字段，并给出错误消息＆＃34;索引超出了数组的范围＆＃34;。有人能够快速查看我的VB代码并给我一个帮助吗？

Private Sub NR1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NR1.Click
    Try

        Dim cn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & My.Application.Info.DirectoryPath.ToString() & "\Flix.Accdb;Persist Security Info=False;")
        If cn.State = ConnectionState.Open Then
            cn.Close()
        End If
        cn.Open()

        Dim dr1 As OleDbDataReader
        Dim com1 As New OleDbCommand
        com1.CommandText = "select [Title],[Poster],[Description],[Classification], [Rating], [Stars], [Director], [MakeYear], [Price], [RunningTime] from tbl_newreleases where ID = '" & "1" & "'"
        com1.Connection = cn
        dr1 = com1.ExecuteReader

        If dr1.Read Then
            NRTitle.Text = (dr1(9)).ToString()
            NRPoster.ImageLocation = (dr1(1)).ToString()
            NRDescription.Text = (dr1(2)).ToString()
            NRClassification.ImageLocation = (dr1(3)).ToString()
            NRStars.ImageLocation = (dr1(4)).ToString()
            lblCast.Text = (dr1(5)).ToString
            lblDirector.Text = (dr1(6)).ToString
            lblYear.Text = (dr1(8)).ToString
            lblPrice.Text = (dr1(10)).ToString
            lblRunTime.Text = (dr1(7)).ToString

        End If
        cn.Close()
        dr1.Close()

        Return
    Catch ex As Exception
        MsgBox(ex.Message(), MsgBoxStyle.Critical, "Error...")
    End Try

End Sub

Answer 1

OleDbDataReader的索引从0开始，因此dr1(10)根据您的查询不存在

As per your query
dr(0) will be the value of [Title] 
dr(1) will be the value of[Poster]
.........
dr(9) will be the value of [RunningTime]

他们不存在dr(10)。这就是你获得Index Out of Range exception

的原因

请按以下方式进行更改

If dr1.Read Then
    NRTitle.Text = dr1(8).ToString()
    NRPoster.ImageLocation = dr1(0).ToString()
    NRDescription.Text = dr1(1).ToString()
    NRClassification.ImageLocation = dr1(2).ToString()
    NRStars.ImageLocation = dr1(3).ToString()
    lblCast.Text = dr1(4).ToString()
    lblDirector.Text = dr1(5).ToString()
    lblYear.Text = dr1(7).ToString()
    lblPrice.Text = dr1(9).ToString()
    lblRunTime.Text = dr1(6).ToString()
End If

Answer 2

 select [Title],[Poster],[Description],[Classification], [Rating], 
[Stars], [Director], [MakeYear], [Price], [RunningTime]  
from tbl_newreleases where ID =

标题= 0海报= 1说明= 2分类= 3评级= 4星= 5 Director = 6 MakeYear = 7 Price = 8 Runningtime = 9

然而，根据列顺序，查询没有多大意义。例如，您似乎将RunningTime的值放入NRTitle.Text，Price的值为lblYear.txt。仍然没有解释为什么Sample给出的答案实际上没有起作用并且阻止了Out of Bounds错误。

If dr1.Read Then
    NRTitle.Text = (dr1(9)).ToString()
    NRPoster.ImageLocation = (dr1(1)).ToString()
    NRDescription.Text = (dr1(2)).ToString()
    NRClassification.ImageLocation = (dr1(3)).ToString()
    NRStars.ImageLocation = (dr1(4)).ToString()
    lblCast.Text = (dr1(5)).ToString
    lblDirector.Text = (dr1(6)).ToString
    lblYear.Text = (dr1(8)).ToString
    lblPrice.Text = (dr1(10)).ToString
    lblRunTime.Text = (dr1(7)).ToString
End If

尝试

If dr1.Read Then
    NRTitle.Text = (dr1(0)).ToString()
    NRPoster.ImageLocation = (dr1(1)).ToString()
    NRDescription.Text = (dr1(2)).ToString()
    NRClassification.ImageLocation = (dr1(3)).ToString()
    NRStars.ImageLocation = (dr1(4)).ToString()
    lblCast.Text = (dr1(5)).ToString
    lblDirector.Text = (dr1(6)).ToString
    lblYear.Text = (dr1(7)).ToString
    lblPrice.Text = (dr1(8)).ToString
    lblRunTime.Text = (dr1(9)).ToString
End If

然后如果仍然失败，请尝试

If dr1.Read Then
    NRTitle.Text = (dr1("Title")).ToString()
    NRPoster.ImageLocation = (dr1("Poster")).ToString()
    NRDescription.Text = (dr1("Description")).ToString()

....（等等使用名称而不是序数

End If

如果你仍然得到Out of Bounds错误，请通过IF语句调试步骤，看看哪一行导致它跳转到CATCH块。如果在此之后仍然不清楚，我可以建议如下：

1）在您正在使用的数据库引擎中运行查询，检查它是否有效并检查是否有任何值显示为NULL

2）对于IF语句中的每一行，每个行的编码略有不同（第一个显示的例子）

dim NRTitleValue as string = trycast(dr1(0),string)      
if NRTitleValue is nothing then
  NRTitle.text = ""
else
  NRTitle.Text = NRTitleValue 
end if

如果在所有这些之后它仍然失败，那么你有一个我多年来从未见过的作为代码猴子的错误！祝你好运，希望你能解决它。

＆＃34;索引超出了数组的范围＆＃34; VB错误

2 个答案: