勾选CHECKBOX之后改变其他控件状态

        /// <summary>
        /// CheckBox押下時
        /// </summary>
        /// <param name="sender">送信するオブジェクト</param>
        /// <param name="e">イベントパラメータ</param>
        protected void RowApprovalCheckBox_OnCheckedChanged(object sender, EventArgs e)
        {
            bool IsChecked = false;

            foreach (GridViewRow row in this.ResultGridView.Rows)
            {
                CheckBox chkbox = (CheckBox)row.FindControl("RowApprovalCheckBox");

                if (chkbox.Checked)
                {
                    IsChecked = true;
                    break;
                }
            }
            this.ApprovalButton.Visible = IsChecked;
        }