((DataGridViewComboBoxColumn)this.dataGridView1.Columns["Column2"]).Items.Add("adfd");

 textBox1.Text = dataGridView1.Rows[0].Cells[1].Value.ToString();

dataGridView1.Rows[0].Cells[0].Value = "没有天理";
dataGridView1.Rows[0].Cells[3].Value = "还没到";
textBox1.Text = dataGridView1.Rows[0].Cells[1].Value.ToString();
textBox1.Text =textBox1.Text+" " +dataGridView1.Rows[0].Cells[2].Value;