elect.aspx.cs

基于asp.net的网上选课系统

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Elect : System.Web.UI.Page
{
    string stuid;
     int num ;

    protected void Page_Load(object sender, EventArgs e)
    {
        
        DataSet ds = new DataSet();

        stuid = (string)Session["userid"];//"20060902";
        string str;
        StuSQL st = new StuSQL();
        st.Open();
        str = "select * from Elective where StudentID=" + "'" + Session["userid"] + "'";//=20060902";
        ds = st.GetDataSet(str, "cours");

        //获取学号为Session["userid"]的学生已选修课程的门数
        num =ds.Tables["cours"].Rows.Count;
        if (!IsPostBack)
        {
            //设置分页控件的数据源
            Pg1.datalist1 = DataList1;
            Pg1.CmdStr = "select Courses.*,Teachers.TeacherName from Courses inner join Teachers on Courses.TeacherID=Teachers.TeacherID";
            ViewState["str"] = Pg1.CmdStr;
        }
        Pg1.CmdStr = (string)ViewState["str"];
        Pg1.datalist1 = DataList1;
        
    }

   private void ElectCurs(string courseid)
   {   
       int aff;
       StuSQL st = new StuSQL();
       st.Open();
       if (st.IsValidPeriod())
       {
           if (st.CourseSelected(stuid, courseid)==0)
           {
               aff = st.ElectCourse(stuid, courseid);
               if (aff != 0 && num <= 2)
               {
                   num += 1;
                   Response.Write("<script>javascript:alert('选修课程成功');</script>");
                   DataList2.EditItemIndex = -1;
                   DataList2.DataBind();
               }
               else if (num > 2)
               {
                   Response.Write("<script>javascript:alert('选修课程失败!你最多可以选修两门课程，而您已经选择了两门课程');</script>");
               }
               else
               {
                   Response.Write("<script>javascript:alert('选修课程失败!);</script>");
               }
           }
           else
           {
               Response.Write("<script>javascript:alert('你已经选修了这门课程，请重新选择！');</script>");
           }
       }
       else
       {
           Response.Write("<script>javascript:alert('不在选课时期内，无法完成相关操作！');</script>");
       }
       st.Close();

    }

    private void deleteCurs(string courseid)
    {
       int aff;
       StuSQL st = new StuSQL();
       st.Open();

       if (st.IsValidPeriod())
       {
           aff = st.CancelCourse(stuid, courseid);
           if (aff > 0)
           {
               num -= 1;
               Response.Write("<script>javascript:alert('退选课程成功');</script>");

           }
           else
           {
               Response.Write("<script>javascript:alert('退选失败！');</script>");
           }
       }
       else
       {
           Response.Write("<script>javascript:alert('不在选课时期内，无法完成相关操作！');</script>");
       }

        DataList2.EditItemIndex = -1;
        DataList2.DataBind();
       st.Close();
    }
    protected void DataList1_ItemCommand(object source, DataListCommandEventArgs e)
    {
        string courseid;
        courseid = DataList1.DataKeys[e.Item.ItemIndex].ToString();
        ElectCurs(courseid);
    }
    protected void DataList2_ItemCommand(object source, DataListCommandEventArgs e)
    {
        string courseid;
        courseid = DataList2.DataKeys[e.Item.ItemIndex].ToString();
        deleteCurs(courseid);
    }

    //根据查询条件搜索数据库中的相应记录
    protected void Button1_Click(object sender, EventArgs e)
    {
        string str,coursname,teaname;
        StuSQL st = new StuSQL();
        st.Open();
        if (txtCourseName.Text != "" || txtTeacherName.Text != "")
        {
            coursname = txtCourseName.Text.Trim();
            teaname = txtTeacherName.Text.Trim();
            if (teaname== "")
            {
                str = "select c.*,t.TeacherName from Courses c inner join Teachers t on c.TeacherID=t.TeacherID where  c.CourseName="+"'"+coursname+"'";
                Pg1.CmdStr = str;
                ViewState["str"] = Pg1.CmdStr;
                Pg1.recordchanged();
               
            }
            else if (coursname == "")
            {
                str = "select c.*,t.TeacherName from Courses c inner join Teachers t on c.TeacherID=t.TeacherID and  t.TeacherName="+"'"+teaname+"'";
                Pg1.CmdStr = str;
                ViewState["str"] = Pg1.CmdStr;
                Pg1.recordchanged();
            }
            else
            {
                str = "select c.*,t.TeacherName from Courses c inner join Teachers t on c.TeacherID=t.TeacherID and  t.TeacherName=" + "'" + teaname + "'";
                str = str + " where  c.CourseName=" + "'" + coursname + "'";
                Pg1.CmdStr = str;
                ViewState["str"] = Pg1.CmdStr;
                Pg1.recordchanged();
            }
        }
        else
        {
            Response.Write("<script>javascript:alert('请输入查询条件！');</script>");
            str = "select Courses.*,Teachers.TeacherName from Courses inner join Teachers on Courses.TeacherID=Teachers.TeacherID";
            Pg1.CmdStr = str;
            ViewState["str"] = Pg1.CmdStr;
            Pg1.recordchanged();
        }
        txtCourseName.Text = "";
        txtTeacherName.Text  = "";
        st.Close();
    }
}