VB.Net中如何实现DataGridView仅导出可见列到CSV文件

开发数据抓取程序时，需要将DataGridView控件中的数据导出为CSV文件，现有代码会导出所有列，需要修改为仅导出界面可见列。原有实现代码如下：

Private Sub CmdCSV_Click(sender As Object, e As EventArgs) Handles CmdCSV.Click
        Dim sfd As New SaveFileDialog()
        sfd.FileName = "export-csv"
        sfd.Filter = "CSV File | *.csv"

        If sfd.ShowDialog() = DialogResult.OK Then
            Using sw As StreamWriter = File.CreateText(sfd.FileName)
                Dim dgvColumnNames As List(Of String) = DataGridView1.Columns.Cast(Of DataGridViewColumn).ToList().Select(Function(c) c.Name).ToList()

                sw.WriteLine(String.Join(";", dgvColumnNames))

                For Each row As DataGridViewRow In DataGridView1.Rows
                    Dim rowData As New List(Of String)

                    For Each column As DataGridViewColumn In DataGridView1.Columns
                        rowData.Add(Convert.ToString(row.Cells(column.Name).Value))
                    Next
                    sw.WriteLine(String.Join(";", rowData))
                Next

            End Using
        End If
    End Sub

核心改动是在列遍历逻辑中增加可见性过滤，同时优化导出逻辑适配界面显示规则、避免CSV格式错乱，修改后的完整代码如下：

Private Sub CmdCSV_Click(sender As Object, e As EventArgs) Handles CmdCSV.Click
    Dim sfd As New SaveFileDialog()
    sfd.FileName = "export-csv"
    sfd.Filter = "CSV File | *.csv"

    If sfd.ShowDialog() = DialogResult.OK Then
        Using sw As StreamWriter = File.CreateText(sfd.FileName)
            ' 仅提取可见列，按界面实际显示顺序排序
            Dim visibleColumns = DataGridView1.Columns.Cast(Of DataGridViewColumn) _
                .Where(Function(c) c.Visible) _
                .OrderBy(Function(c) c.DisplayIndex) _
                .ToList()

            ' 写入表头，使用界面显示的列标题而非列内部名
            Dim headerLine = String.Join(";", visibleColumns.Select(Function(c) c.HeaderText))
            sw.WriteLine(headerLine)

            ' 逐行写入数据
            For Each row As DataGridViewRow In DataGridView1.Rows
                ' 跳过控件底部未提交的空白新行
                If row.IsNewRow Then Continue For

                Dim rowData As New List(Of String)
                For Each col As DataGridViewColumn In visibleColumns
                    Dim cellVal = Convert.ToString(row.Cells(col.Name).Value)
                    ' 对包含分隔符、引号、换行的内容做标准CSV转义，避免列错位
                    If cellVal.Contains(";") OrElse cellVal.Contains("""") OrElse cellVal.Contains(vbCrLf) Then
                        cellVal = $"""{cellVal.Replace("""", """""")}"""
                    End If
                    rowData.Add(cellVal)
                Next
                sw.WriteLine(String.Join(";", rowData))
            Next
        End Using
    End If
End Sub

• 过滤可见列：通过.Where(Function(c) c.Visible)筛选掉隐藏列，不会导出用户在界面上看不到的字段
• 匹配界面顺序：增加.OrderBy(Function(c) c.DisplayIndex)保证导出列顺序和用户在界面上看到、调整后的列顺序完全一致，避免列顺序错乱
• 剔除无效空行：判断row.IsNewRow跳过DataGridView底部默认的空白新增行，避免导出多余空内容
• 兼容CSV格式规范：对包含分隔符、引号、换行的单元格值做标准转义处理，避免用Excel等工具打开CSV时出现列拆分错位的问题

内容的提问来源于stack exchange，提问作者framadh