效果图：

 

一.Form添加全局变量

//这里的值是表格行头的初始宽度

int rowHeaderWidth = 41;

二.DataGridView添加事件

private void dgvReconcile_RowsRemoved(object sender, DataGridViewRowsRemovedEventArgs e)         {
               ChangeRowHeaderWidth();         } private void dgvReconcile_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)         {
               ChangeRowHeaderWidth();         } private void dgvReconcile_RowHeadersWidthChanged(object sender, EventArgs e)         {
               //这里是移动全选复选框的位置 int offw = dgvReconcile.RowHeadersWidth - rowHeaderWidth;             cbSelectAll.Location = new Point(cbSelectAll.Location.X + offw, cbSelectAll.Location.Y);             rowHeaderWidth = dgvReconcile.RowHeadersWidth;         } private void dgvReconcile_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)         {
   if (dgvReconcile.Rows.Count > 0)             {
   using (SolidBrush b = new SolidBrush(e.RowIndex == dgvReconcile.CurrentRow.Index ? Color.Red : dgvReconcile.RowHeadersDefaultCellStyle.ForeColor))                 {
                       e.Graphics.DrawString((Convert.ToInt32(e.RowIndex) + 1).ToString(System.Globalization.CultureInfo.CurrentCulture), e.InheritedRowStyle.Font, b, e.RowBounds.Location.X + 20, e.RowBounds.Location.Y + 4);                 }             }         }

其中ChangeRowHeaderWidth方法代码：

///
         ///计算表格序号列宽度         ///         private void ChangeRowHeaderWidth()         {
               Graphics g = Graphics.FromHwnd(dgvReconcile.Handle);             SizeF sf = g.MeasureString(dgvReconcile.Rows.Count.ToString(), dgvReconcile.Font);             dgvReconcile.RowHeadersWidth = (int)Math.Ceiling(sf.Width + 20);         }