实现DataGridView的按Shift多选

将DataGridView的MultiSelect属性设置为：true

然后设置：SelectionChanged事件。如：

        private void dgvCustomer_SelectionChanged(object sender, EventArgs e)
        {
            labRowSelectCount.Text = dgvCustomer.SelectedRows.Count.ToString();
            for (int i = 0; i < dgvCustomer.Rows.Count; i++)
            {
                dgvCustomer.Rows[i].Cells[0].Value = dgvCustomer.Rows[i].Selected;
            }
        }