DataGridView同时删除多行

private void button1_Click(object sender, EventArgs e)
        ...{
            this.hostTableAdapter.Fill(this.hostScanDataSet.host);
        }

        private void button2_Click(object sender, EventArgs e)
        ...{
            this.hostTableAdapter.Update(this.hostScanDataSet.host);
            MessageBox.Show("记录已保存!");
        }

        private void button3_Click(object sender, EventArgs e)
        ...{
            DialogResult dlResult = MessageBox.Show(this, "要删除这些记录吗？", "请确认",
                MessageBoxButtons.YesNo,
                MessageBoxIcon.Question,
                MessageBoxDefaultButton.Button1,
                MessageBoxOptions.RightAlign);
            if (dlResult == DialogResult.Yes)
            ...{
                int j = dataGridView1.SelectedRows.Count;
                int[] l = new int[j];

                int i;
                for (i = 0; i < j; i++)
                ...{
                    l[i] = dataGridView1.SelectedRows[i].Index;
                }

                int k = 0;
                while (k < j)
                ...{
                    this.hostScanDataSet.host.Rows[l[k]].Delete();
                    k++;
                }
                this.hostTableAdapter.Update(this.hostScanDataSet.host);
            }
         }