使用windows form app中的vb.net将.csv文件合并到datagridview中当“列”是基于行的，需要透视。

Imports System.IO
Imports System.Data.OleDb

Public Class Form1
    Private Sub btnMerge_Click(sender As Object, e As EventArgs) Handles btnMerge.Click
        ' 打开文件对话框选择要合并的.csv文件
        Dim openFileDialog As New OpenFileDialog()
        openFileDialog.Filter = "CSV Files (*.csv)|*.csv"
        openFileDialog.Multiselect = True

        If openFileDialog.ShowDialog() = DialogResult.OK Then
            ' 创建一个DataTable来存储合并后的数据
            Dim mergedDataTable As New DataTable()

            ' 遍历选择的每个.csv文件
            For Each filePath As String In openFileDialog.FileNames
                ' 读取.csv文件的数据
                Dim csvData As String = File.ReadAllText(filePath)

                ' 使用逗号分隔符解析.csv数据
                Dim csvRows As String() = csvData.Split(ControlChars.Lf)

                ' 如果DataTable还没有列，则根据第一行创建列
                If mergedDataTable.Columns.Count = 0 Then
                    Dim csvColumns As String() = csvRows(0).Split(","c)
                    For Each csvColumn As String In csvColumns
                        mergedDataTable.Columns.Add(csvColumn)
                    Next
                End If

                ' 遍历.csv文件的每一行数据（从第二行开始）
                For i As Integer = 1 To csvRows.Length - 1
                    Dim csvValues As String() = csvRows(i).Split(","c)

                    ' 创建一个新的DataRow来存储.csv行数据
                    Dim newRow As DataRow = mergedDataTable.NewRow()

                    ' 将.csv行数据添加到新的DataRow中
                    For j As Integer = 0 To csvValues.Length - 1
                        newRow(j) = csvValues(j)
                    Next

                    ' 将新的DataRow添加到DataTable中
                    mergedDataTable.Rows.Add(newRow)
                Next
            Next

            ' 将合并后的DataTable绑定到DataGridView中显示
            DataGridView1.DataSource = mergedDataTable
        End If
    End Sub
End Class