gridview中checkbox不可选

 protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)

    {

        this.Label1.Text = "";

        CheckBox ck = (CheckBox)this.GridView1.Rows[e.RowIndex].Cells[4].Controls[0];

        

        bool b = ck.Checked;

        if (!b)

        {

            string uname = this.GridView1.Rows[e.RowIndex].Cells[1].Text.ToString();

            string date = this.GridView1.Rows[e.RowIndex].Cells[3].Text.ToString();

            string num = this.GridView1.Rows[e.RowIndex].Cells[2].Text.ToString();



            if (bs.doProcedure("exec prc_addcoins '" + uname + "','" + date + "'," + num))

            {

                this.Label1.Text = "<script>alert('处理成功')</script>";

                this.fillTable();

            }

        }

        else

        {

            this.Label1.Text = "<script>alert('已经处理')</script>";