DataGridViewCheckBoxCell cell = new DataGridViewCheckBoxCell();
        public test()
        {
            InitializeComponent();
            cell.FalseValue = 0;
            cell.TrueValue = 1;
            
        }

        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            int rowindex = e.RowIndex;
            int columnindex = e.ColumnIndex;
            if (columnindex == 0)
            {
                
                cell = (DataGridViewCheckBoxCell)this.dataGridView1.Rows[rowindex].Cells[0];
                
                object a = cell.Value;
                a = cell.FormattedValue;
                a = cell.Tag;
                
               DataGridViewElementStates state =this.dataGridView1.Rows[rowindex].Cells[0].State;              
            }

        }

------解决方案--------------------
应该让微软提供CellValueChanged事件处理。