st_student_course.aspx.cs

学生管理系统（asp.net+sql server）

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Configuration;

namespace STGROUP
{
	/// <summary>
	/// student_course 的摘要说明。
	/// </summary>
	public class ST_student_course : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Button st_btn_student;
		protected System.Web.UI.WebControls.DataGrid st_dtg_sort;
		protected System.Web.UI.WebControls.Label st_lbl_all;
		protected System.Web.UI.WebControls.TextBox st_tbx_year;
		protected System.Web.UI.WebControls.Label st_lbl_note;
		protected System.Web.UI.WebControls.DropDownList st_ddl_course;
		protected System.Web.UI.WebControls.DropDownList st_ddl_teacher;
		protected System.Web.UI.WebControls.Button st_btn_exit;
	    SqlConnection st_conn;
		private void Page_Load(object sender, System.EventArgs e)
		{   //教师名称下拉列表框绑定
			string st_connstr= ConfigurationSettings.AppSettings["st_dbconn"];
			//连接本地计算机的sms数据库
			SqlConnection st_conn1= new SqlConnection (st_connstr);
			if(!IsPostBack)
			{
				st_conn1.Open ();
				string mysql="select * from ST_teacher";
				SqlCommand st_comm1=new SqlCommand  (mysql,st_conn1);
				SqlDataReader st_dr1=st_comm1.ExecuteReader ();
				while(st_dr1.Read ())
				{
					st_ddl_teacher.Items .Add (new ListItem(st_dr1["ST_Teacher_name"].ToString(),st_dr1["ST_Teacher_id"].ToString()) );
				}
				st_conn1.Close ();
				//课程名称下拉列表框绑定
				st_conn1.Open ();
				string st_sqlstr2="select * from ST_course";
				SqlCommand st_comm2=new SqlCommand  (st_sqlstr2,st_conn1);
				SqlDataReader st_dr2=st_comm2.ExecuteReader ();
				while(st_dr2.Read ())
				{
					st_ddl_course.Items .Add (new ListItem(st_dr2["ST_Course_name"].ToString() ,st_dr2["ST_Course_id"].ToString()) );
				}
				st_conn1.Close ();
			}
			// 在此处放置用户代码以初始化页面
			st_conn=new SqlConnection(st_connstr);
			
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN：该调用是 ASP.NET Web 窗体设计器所必需的。
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// 设计器支持所需的方法 - 不要使用代码编辑器修改
		/// 此方法的内容。
		/// </summary>
		private void InitializeComponent()
		{    
			this.st_btn_student.Click += new System.EventHandler(this.st_btn_student_Click);
			this.st_btn_exit.Click += new System.EventHandler(this.st_btn_exit_Click);
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion

		private void st_btn_student_Click(object sender, System.EventArgs e)
		{
			ST_BindGrid();		  
		}
		public void DataGrid_Page(object sender,DataGridPageChangedEventArgs e)
		{
			st_dtg_sort.CurrentPageIndex=e.NewPageIndex;
			ST_BindGrid();
		}
		public void DataGrid_delete(object sender,DataGridCommandEventArgs e)
		{
			
			string st_sqlstr="delete from ST_student_course where ST_ID=@id";
			SqlCommand st_comm=new SqlCommand(st_sqlstr,st_conn);
			st_comm.Parameters.Add(new SqlParameter("@id",SqlDbType.BigInt,8));
			st_comm.Parameters["@id"].Value=st_dtg_sort.DataKeys[(int)e.Item.ItemIndex];
			st_comm.Connection.Open();
			try
			{
				st_comm.ExecuteNonQuery();
				st_lbl_note.Text="删除成功";
				
			}
			catch(SqlException)
			{
				st_lbl_note.Text="删除失败";
				st_lbl_note.Style["color"]="red";
			}
			st_comm.Connection.Close();			
			ST_BindGrid();
		}
		
		public void ST_BindGrid()
		{
			//查询 sql语句字符串
			string st_sqlstr="select ST_student_course.ST_ID,ST_student.ST_Student_id,ST_student.ST_Student_classid from ST_student_course,ST_student,ST_teacher_course where ST_student_course.ST_Course_id='"+st_ddl_course.SelectedItem.Value+"' and ST_student_course.ST_Course_year=ST_teacher_course.ST_Course_year and ST_student_course.ST_Course_year='"+st_tbx_year.Text+"'and ST_teacher_course.ST_Teacher_id='"+st_ddl_teacher.SelectedItem.Value+"'and ST_student_course.ST_Course_id=ST_teacher_course.ST_Course_id and ST_student.ST_Student_id=ST_student_course.ST_Student_id";
			SqlDataAdapter st_da=new SqlDataAdapter(st_sqlstr,st_conn);
			DataSet st_ds=new DataSet();
			st_da.Fill(st_ds);
			st_dtg_sort.DataSource=st_ds;
			st_dtg_sort.DataBind();
			string strsq="select COUNT(*) from ST_student_course,ST_student,ST_teacher_course where ST_student_course.ST_Course_id='"+st_ddl_course.SelectedItem.Value+"' and ST_student_course.ST_Course_year=ST_teacher_course.ST_Course_year and ST_student_course.ST_Course_year='"+st_tbx_year.Text+"'and ST_teacher_course.ST_Teacher_id='"+st_ddl_teacher.SelectedItem.Value+"'and ST_student_course.ST_Course_id=ST_teacher_course.ST_Course_id and ST_student.ST_Student_id=ST_student_course.ST_Student_id";
			SqlCommand st_comm1=new SqlCommand(strsq,st_conn);		
			st_conn.Open();
			SqlDataReader dr=st_comm1.ExecuteReader();
			if(dr.Read())
			{
					st_lbl_all.Text="选课总人数为："+dr[0].ToString();
			}
			else
			{
				st_lbl_all.Text="无人选此课";
			}
			st_conn.Close();
		}

		private void st_btn_exit_Click(object sender, System.EventArgs e)
		{
			Response.Redirect("default.aspx");
		}

		
	}
}