Question

您好我正在尝试仅在特定列中循环行。但是我没有成功，任何人都可以帮助我。这是我的代码，myXvalue =“CPI”是列标题名称。

Dim myXvalue = "CPI"

 For Each column As DataColumn In dt.Columns


                If column.ColumnName = myXvalue Then

                    For k As Integer = 0 To dt.Rows(myXvalue).Count - 1

                        Console.WriteLine(myXvalue & " === " & dt.Rows(0)(k).ToString)


                    Next

                    Console.ReadKey(True)


                End If

Answer 1

这应该可以解决问题。

Dim dt As New DataTable()
For Each dr As DataRow In dt.Rows
    If dr.Item("myColumnHeaderName").ToString = "certainColumnValue" Then
        Console.WriteLine(dr.Item("myColumn").ToString())
    End If
Next

Answer 2

一个。在visual basic.net中，更好的做法是定义字段或属性的类型。
使用Dim myXvalue As String = "CPI"而不是Dim myXvalue = "CPI"。
如果您熟悉c＃，则此约定与c＃中的var不完全相同：
Is VB's Dim the same as C#'s var?

湾下面的代码是实现您所需要的一种方式。

Private Sub Func()
    Dim myXvalue As String = "CPI"
    Dim colIndex As Integer = -1

    For i As Integer = 0 To dt.Columns.Count - 1
        If dt.Columns(i).ColumnName = myXvalue Then
            colIndex = i
            Exit For
        End If
    Next

    If colIndex = -1 Then
        ' only for safty if this column name is not exist
        Exit Sub
    End If

    For i As Integer = 0 To dt.Rows.Count - 1
        Console.WriteLine((myXvalue & "===" & dt.Rows(i).Item(colIndex).ToString()))
    Next

    Console.ReadKey(True)
End Sub

Answer 3

有了这个，你从一列获得所有项目的列表

Dim col_allitems as string = myData.Rows.Cast(Of DataRow).Select(Function(row) row.Item(1).ToString)

vb.net datatable按特定列名循环遍历行

3 个答案: