Winform DataGridView复制表格内容为CSV

csv内容可直接复制到微软Excel表格中，wps这么复制是不支持的，用原生DataGridView复制方式即可两种办公软件都兼容，csv方式仅作笔记。

核心代码：

private void btnCopy_Click(object sender, EventArgs e)
{
    try
    {
        var csv = (DataGridView1.ToDataTable()).ToCsv();
        var bytes = System.Text.Encoding.Default.GetBytes(csv);  //必须转码
        using (var stream = new System.IO.MemoryStream(bytes))
            Clipboard.SetData(System.Windows.Forms.DataFormats.CommaSeparatedValue, stream);

　　　　　//DataGridView自带复制粘贴方式
　　　　  //dg.SelectAll();
　　　　  //Clipboard.SetDataObject(dg.GetClipboardContent());
　　　　　//dg.ClearSelection();
    }
    catch (Exception ex)
  　{
　　　　MessageBox.Show(ex.Message);
　　 }
}

static class Extentions
{
    /// <summary>
    /// DataTable转Csv
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string ToCsv(this DataTable dt)
    {
        StringBuilder builder = new StringBuilder();

        IEnumerable<string> columnNames = dt.Columns.Cast<DataColumn>().Select(column => string.IsNullOrWhiteSpace(column.Caption) ? column.ColumnName : column.Caption);
        builder.AppendLine(string.Join(",", columnNames));

        foreach (DataRow row in dt.Rows)
        {
            IEnumerable<string> fields = row.ItemArray.Select(field =>
            {
                string s = field.ToString().Replace("\"", "\"\"");
                if (s.Contains(','))
                    s = string.Concat("\"", s, "\"");
                return s;
            });
            builder.AppendLine(string.Join(",", fields));
        }

        return builder.ToString().Trim();
    }

    /// <summary>
    /// 将DataGridView里面的数据提取到DataTable中
    /// </summary>
    /// <param name="dataGridView"></param>
    /// <returns></returns>
    public static DataTable ToDataTable(this DataGridView dataGridView)
    {
        var dataTable = new DataTable();

        for (var i = 0; i < dataGridView.RowCount; i++)
        {
            var dr = dataTable.NewRow();
            for (var j = 0; j < dataGridView.ColumnCount; j++)
            {
                if (i == 0)
                {
                    var dc = new DataColumn(dataGridView.Columns[j].Name);
                    dc.Caption = dataGridView.Columns[j].HeaderText;
                    dataTable.Columns.Add(dc);
                }

                dr[j] = dataGridView[j, i].Value;
            }
            dataTable.Rows.Add(dr);
        }

        return dataTable;
    }
}