。net逻辑判断问题

如果任务编码下没有收费序号就显示新建并且页面为空，如果任务编码下游对应的收费序号则显示保存，如果有多个则显示上下页和保存，上下页可以查看同一个任务编码下的所有收费记录。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using AnchorV7.FirstAidManager.SE.Model;
using System.Web.UI.HtmlControls;
using System.Data;
using SQLServerDAL;

//------------------------------------------------------------------------------
///       FileName: MedicalManagement_ChargeRecord
///       Function: 收费记录页面
///         Author: 刘爱青
///           Date: 2011-6-3
///       Modified:
//------------------------------------------------------------------------------
public partial class MedicalManagement_ChargeRecord : System.Web.UI.Page
{
    private static int ChargeItemNumber = 1; //收费序号
    public string TaskCode
    {
        get
        {
            object o = ViewState["TaskCode"];
            return (o == null) ? String.Empty : (string)o;
        }
        set
        {
            ViewState["TaskCode"] = value;
        }
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        //SessionHelper.ValidateLogin(Response, Session);//防止通过链接强行进入
        if (!IsPostBack)
        {
            InitPage();
        }
        TaskCode = "20110317205726020101";
        string sql = " select * from TChargeRecordDetailPT where 任务编码='TaskCode'and 收费序号=(select min(收费序号) from TChargeRecordDetailPT where 任务编码='TaskCode')";
        object ob = DBHelper.GetScalar(sql);
        if (ob == null)
        {
            return;
        }
        else
        {

        }

    }
    /// <summary>
    /// 页面初始化
    /// </summary>
    private void InitPage()
    {
        //TaskCode = Request.QueryString["TaskCode"];
        TaskCode = "20110317205726020101";
        string sql1 = "SELECT TOP 23 收费项编码,收费项名称,收费金额 FROM TChargeItemPT WHERE (收费金额 IS NOT NULL)";
        DataTable dt1 = DBHelper.GetTable(sql1);
        GridView_ChargeRecord1.DataSource = dt1;
        GridView_ChargeRecord1.DataBind();

        string sql2 = "SELECT 收费项编码,收费项名称,收费金额 FROM TChargeItemPT WHERE (收费金额 IS NOT NULL) and 29<=编码 and 编码<=52";
        DataTable dt2 = DBHelper.GetTable(sql2);
        GridView_ChargeRecord2.DataSource = dt2;
        GridView_ChargeRecord2.DataBind();
    }

    protected void Btn_onClick1(object sender, GridViewCommandEventArgs e)
    {

        int RowIndex = Convert.ToInt32(e.CommandArgument);       //取得行号
        DataKey keys = GridView_ChargeRecord1.DataKeys[RowIndex];  //取得行中数据
        string ChargeItemName = (string)keys.Values["收费项名称"];
        float Price = Convert.ToSingle(keys.Values["收费金额"]);
        HtmlInputText tb = (HtmlInputText)GridView_ChargeRecord1.Rows[RowIndex].FindControl("TextBox_Amout1");
        tb.Value = Price.ToString();
    }
    protected void Btn_onClick2(object sender, GridViewCommandEventArgs e)
    {

        int RowIndex = Convert.ToInt32(e.CommandArgument);       //取得行号
        DataKey keys = GridView_ChargeRecord2.DataKeys[RowIndex];  //取得行中数据
        string ChargeItemName = (string)keys.Values["收费项名称"];
        float Price = Convert.ToSingle(keys.Values["收费金额"]);
        HtmlInputText tb = (HtmlInputText)GridView_ChargeRecord2.Rows[RowIndex].FindControl("TextBox_Amout2");
        tb.Value = Price.ToString();
    }

    /// <summary>
    /// 保存
    /// </summary>
    protected void BtnSave_onClick(object sender, EventArgs e)
    {
        string StationCode = "013";

        List<ChargeRecordDetailInfo> crList = new List<ChargeRecordDetailInfo>();
        for (int i = 0; i < GridView_ChargeRecord1.Rows.Count; i++)
        {
            DataKey keys = GridView_ChargeRecord1.DataKeys[i];
            string ChargeItemId = (string)keys.Values["收费项编码"];
            GridViewRow gvr = GridView_ChargeRecord1.Rows[i];
            HtmlInputText tb = (HtmlInputText)gvr.FindControl("TextBox_Amout1");

            string sqlChargeOrder= "select top 1 (收费单编号) from dbo.TChargeRecordDetailPT ";
            int OrderNum = Convert.ToInt32(((string)DBHelper.GetScalar(sqlChargeOrder)).Substring(10, 14));
            int num = OrderNum + 1;
            string ChargeOrderNumber = "'PT' + '" + StationCode + "' + '" + DateTime.Now.Year + "' + 'num' ";

            if (tb.Value == "")
            {
                continue;
            }
            else
            {
                ChargeRecordDetailInfo crInfo = new ChargeRecordDetailInfo();
                crInfo.TaskCode = TaskCode;
                crInfo.ChargeItemId = ChargeItemId;
                crInfo.Price = Convert.ToSingle(tb.Value);
                crInfo.ChargeItemNumber = ChargeItemNumber;
                crInfo.StationCode = StationCode;
                crInfo.Remark = "";
                crList.Add(crInfo);
            }
        }

        ChargeRecordDAL crDAL = new ChargeRecordDAL();
        if (crDAL.SaveCharge(crList))
        {
            Response.Write("<script>alert('保存成功！')</script>");
        }
        else
        {
            Response.Write("<script>alert('保存失败！')</script>");
        }
    }
}

补充：.NET技术 ,  ASP.NET