DataTable:如何使用行名和列名获取项目值?(VB) [英] DataTable: How to get item value with row name and column name? (VB)

问题描述

我有一个简单的 DataTable，其中一列包含唯一值.例如:

I have a simple DataTable where one of the columns contains unique values. For example:

ColumnName1   ColumnName2
value1        35
value2        44
value3        10

因为我知道值 1、2 和 3 总是彼此不同，所以我想仅使用 ColumnName2 和 列名 1.例如:

Because I know that value 1, 2 and 3 will always be different one from another, I would like to get a value of this table only using ColumnName2 and one of the values of ColumnName1. That would for example be:

searchedValue = DataTable.Rows("value3").Item("ColumnName2) 
'result would be 10

我尝试了以下示例失败:

I tried the following examples unsuccessfully:

• 使用 DataTable.Select 方法:返回一个行数组，但我只需要一个

• with the DataTable.Select method: returns an array of rows, but I only need one

使用 DataTable.Rows.IndexOf 方法:如果我很好理解，我需要提供整行内容才能使用此方法找到它.

with the DataTable.Rows.IndexOf method: if I understood well, I need to provide the whole row contents for it to be found with this method.

推荐答案

Dim rows() AS DataRow = DataTable.Select("ColumnName1 = 'value3'")
If rows.Count > 0 Then
     searchedValue = rows(0).Item("ColumnName2") 
End If

使用 FirstOrDefault:

Dim row AS DataRow = DataTable.Select("ColumnName1 = 'value3'").FirstOrDefault()
If Not row Is Nothing Then
     searchedValue = row.Item("ColumnName2") 
End If

在 C# 中:

var row = DataTable.Select("ColumnName1 = 'value3'").FirstOrDefault();
if (row != null)
     searchedValue = row["ColumnName2"];

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