Question

每次我尝试获取每一行的第一列值时都会收到此错误。

Dim modAdapter As New StudentSystemDBDataSetTableAdapters.modulesTableAdapter
Dim modDataset As New StudentSystemDBDataSet

If modAdapter.ModulesCountRow() <> 0 Then
    For x As Integer = 0 To modAdapter.ModulesCountRow()
        Dim column As String = modDataset.modules.Rows(x)(0).ToString
        MsgBox(column)
    Next
End If`

Answer 1

索引为零。因此，第一行位于modDataset.modules.Rows(0)，最后一行位于modDataset.modules.Rows(modAdapter.ModulesCountRow() - 1)。

所以你必须减去1：

For x As Integer = 0 To modAdapter.ModulesCountRow() - 1
    Dim column As String = modDataset.modules.Rows(x)(0).ToString
    MsgBox(column)
Next

修改：您也可以使用DataTable.Rows.Count属性（如果已填充）。然后，您不需要使用dataadapter从数据库获取行计数：

For x As Integer = 0 To modDataset.modules.Rows.Count - 1
    Dim column As String = modDataset.modules.Rows(x)(0).ToString
    MsgBox(column)
Next

Answer 2

确保您的数据集（模块）包含行：

If modDataset.modules.Rows.Count > 0 AndAlso modAdapter.ModulesCountRow() <> 0 Then
            For x As Integer = 0 To modAdapter.ModulesCountRow()
                Dim column As String = modDataset.modules.Rows(x)(0).ToString
                MsgBox(column)
            Next
        End If

位置0错误TableAdapter没有行

2 个答案: