vb.net 数据表按特定列名循环遍历行
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vb.net datatable loop through rows by specific column name
提问by tharun
Hi i am trying to loop through row only in specific column. However i did not succeed, can any one help me. Here is my code, myXvalue = "CPI" is the column header Name.
嗨，我正在尝试仅在特定列中循环遍历行。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
采纳答案by jonathana
a. In visual basic.net a better practice is to define the types of fields or propeties.
use Dim myXvalue As String = "CPI"and not Dim myXvalue = "CPI".
if you familiar with c# this convention is not exactly like varin c#:
Is VB's Dim the same as C#'s var?
一种。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# 中的不完全相同var：
VB 的 Dim 与 C# 的 var 相同吗？
b. the code below is one way to achieve what you need.
湾 下面的代码是实现您所需要的一种方法。
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
回答by Nick Painter
This should do the trick.
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
回答by Peter Schneider
With this you get a list of all Items from one Column
有了这个，您可以获得一列中所有项目的列表
Dim col_allitems as string = myData.Rows.Cast(Of DataRow).Select(Function(row) row.Item(1).ToString)
