从DataGridView获取DataTable

private void button1_Click(object sender, EventArgs e)
{
    DataTable dt = new DataTable();
    foreach (DataGridViewColumn column in dataGridView1.Columns)
    {
        dt.Columns.Add(column.Name);
    }
    foreach (DataGridViewRow row in dataGridView1.Rows)
    {
        DataRow dr = dt.NewRow();
        foreach (DataGridViewCell cell in row.Cells)
        {
            dr[cell.ColumnIndex] = cell.Value;
        }
        dt.Rows.Add(dr);
    }
    // 现在，dt 包含了 DataGridView 控件中的数据
}