GridView中根據CheckBox選中的行取出某列的值

根據CheckBox選中的行取出某列的值：

for (int i = 0; i < this.GridView1.Rows.Count; i++)
        {
            CheckBox ckb = (CheckBox)this.GridView1.Rows[i].Cells[0].FindControl("CheckBox1");
            if (ckb.Checked)
            {
                huohao =Convert.ToInt32(this.GridView1.Rows[i].Cells[2].Text);
                shuliang = Convert.ToInt32(this.GridView1.Rows[i].Cells[3].Text);
                danjia =Convert.ToDecimal(this.GridView1.Rows[i].Cells[4].Text);
                heJiJinE =Convert.ToDecimal(this.GridView1.Rows[i].Cells[5].Text);
                jinhuoId =Convert.ToInt32(this.GridView1.Rows[i].Cells[7].Text);
            }
        }

gridview如何讓某一行上來默認被選中呢

foreach (GridViewRow dr in GridView1.Rows)  
  {
  CheckBox ckbRow = (CheckBox)Gridview.FindControl("ckbRow");//取道數據庫的值，在選中

  if(ckbRow.argumentName=="4")
  {
  ckbRow.Visible = true;
  }
  else
  {
  ckbRow.Visible = false;
  }
  }