程序代码：

      private void Button1_Click(object sender, EventArgs e)
        {
            StringBuilder sb = new StringBuilder();
            int count = this.dataGridView1.GetCellCount(DataGridViewElementStates.Selected);
            for (int i = 0; i < count; i++)
            {
                sb.Append(dataGridView1.SelectedCells[i].Value.ToString ());
                sb.Append(" ");
            }
            AddItemToListBox1(sb.ToString());
        }

      private void AddItemToListBox1(string str)
        {
            listBox1.Items.Add(str);
            listBox1.SelectedIndex = listBox1.Items.Count - 1;
            listBox1.ClearSelected();           
        }