求解释，代码很简单，但是我想不明白，望明白的认识指点下
程序代码：<%@ WebHandler Language="C#" Class="deldata" %>
using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.Collections.Generic;
public class deldata : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
Model model = new Model();
model.FName = context.Request.Form["FName"];
model.FCategoryID = IsNull(context.Request.Form["Fcate"]) ? (int?)Convert.ToInt32(context.Request.Form["Fcate"]) : null;
model.FAuthor = context.Request.Form["Fauthor"];
model.IsDel = IsNull(context.Request.Form["Fcate"]) ? (bool?)Convert.ToBoolean(context.Request.Form["IdDel"]) : null; //context.Request.Form["IdDel"];
model.FYearPublished = IsNull(context.Request.Form["Fyear"]) ? (int?)Convert.ToInt32(context.Request.Form["Fyear"]) : null;//(int?) Convert.ToInt32(context.Request.Form["Fyear"]);
//这里不理解，求解释
int rel = DelExecuteNonQuery(model, context);
if (rel <= 0)
{
context.Response.Write("alert(\"删除失败\");");
}
else
{
context.Response.Redirect("SelecteData.ashx");
}
}
public bool IsNull(object value)
{
if (value.ToString().Trim().Length == 0)
{
return false;
}
else
{
return true;
}
}
public bool IsReusable
{
get
{
return false;
}
}
public int DelExecuteNonQuery(Model model, HttpContext context)
{
List<SqlParameter> sqlParameterList = new List<SqlParameter>();
List<string> sqlList = new List<string>();
string sqlStr = "delete from T_Book";
if (model.FName.ToString().Trim().Length > 0)
{
sqlList.Add("FName like @FName");
sqlParameterList.Add(new SqlParameter("@FName", "%" + model.FName + "%"));
}
if (model.FCategoryID != null)
{
sqlList.Add("FCategoryID like @FCategoryID");
sqlParameterList.Add(new SqlParameter("@FCategoryID", "%" + model.FCategoryID + "%"));
}
if (model.FYearPublished != null)
{
sqlList.Add("FYearPublished like @FYearPublished");
sqlParameterList.Add(new SqlParameter("@FYearPublished", "%" + model.FYearPublished + "%"));
}
if (model.IsDel != null)
{
sqlList.Add("IsDel like @IsDel");
sqlParameterList.Add(new SqlParameter("@IsDel", "%" + model.IsDel + "%"));
}
if (model.FAuthor != string.Empty)
{
sqlList.Add("FAuthor like @FAuthor");
sqlParameterList.Add(new SqlParameter("@FAuthor", "%" + model.FAuthor + "%"));
}
if (sqlList.Count > 0)
{
string sqlTxt = string.Join(" and ", sqlList.ToArray());
sqlStr = sqlStr + " where " + sqlTxt;
}
else
{
context.Response.Write("alert(\" 你会把所有数据都删除掉的！！！\");");
return 0;
}
SqlConnection con = new SqlConnection(@"Data Source=.;Initial Catalog=Books;User ID=sa;Password=123");
con.Open();
SqlCommand com = new SqlCommand();
com.Connection = con;
= sqlStr;
com.Parameters.AddRange(sqlParameterList.ToArray());
int rel = com.ExecuteNonQuery();
return rel;
}
}
这算个模糊查询删除记录的一个小程序吧，HTML代码就不写了，这个是一般处理程序，问题就是我明明已经把要删除的记录删除了，并且上述做标记处代码中的rel变量是大于0的，但是调试过程中不知道什么原因，（我在if判断出设了断点），走到if判断处，按F11，语句往下执行，但是再按F11 又回到if判断处了，并且rel变量为0，求解释。期待中。。。。。。[ 本帖最后由 lxb932979339 于 2013-5-30 21:33 编辑 ]
