DataGridView自定义单元格表示值、Error图标显示的方法介绍

private void dgv_Users_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            try
            {
                if (e == null || e.Value == null || !(sender is DataGridView))
                    return;
                DataGridView dgv = sender as DataGridView;
                if (dgv.Columns[e.ColumnIndex].Name=="Sex")
                {
                    string value = e.Value.ToString();
                    if (value.Equals("女"))
                    {
                        e.Value = "Woman";
                        e.FormattingApplied = true;
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message + "\r\n" + ex.StackTrace);
            }
        }

this.dgv_Users[0, 0].ErrorText = "只能输入男或女";

this.dgv_Users.Rows[3].ErrorText = "不能输入负数";

private void dgv_Users_CellErrorTextNeeded(object sender, DataGridViewCellErrorTextNeededEventArgs e)
{
            DataGridView dgv=sender as DataGridView;

            if (dgv.Columns[e.ColumnIndex].Name.Equals("Sex"))
            {
                string value = dgv[e.ColumnIndex, e.RowIndex].Value.ToString();
                if (!value.Equals("男") && !value.Equals("女"))
                {
                    e.ErrorText = "只能输入男或女";
                }
            }
}

private void dgv_Users_RowErrorTextNeeded(object sender, DataGridViewRowErrorTextNeededEventArgs e)
{
            DataGridView dgv = sender as DataGridView;
            if (dgv["UserName", e.RowIndex].Value == DBNull.Value && dgv["Password", e.RowIndex].Value == DBNull.Value)
            {
                e.ErrorText = "UserName和Password列必须输入值";
            }
}