根据DataGridView中的CHECKBOX状态求和

//Amount在构造函数里初始 就是先把打钩的金额加起来赋给Amount
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            //Column1是普通列
            //Column2是checkbox列
            if (e.ColumnIndex == Column2.Index)
            {
                
                if (dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].EditedFormattedValue.ToString() == "True")
                    Amount = Amount + Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[Column1.Index].Value);
                else
                    Amount = Amount - Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[Column1.Index].Value);
                textBox1.Text = Amount.ToString();

            }
        }