teachersubmit.aspx.cs

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using System;
using System.Data;
using System.Data.SqlClient;
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 teachersubmit : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Session["Username"] == null)//如果没有登录，转向登录界面
        {
            Response.Redirect("Login.aspx");
        }
        else
        {
            if (!IsPostBack)
            {
                ImageButton1.Attributes.Add("OnClick", "javascript:return confirm('您只能提交一次成绩，确实要提交吗？')");        //成绩只能提交一次，给出提示
                BindDDL();
                bind();
            }//绑定GridView         
        }
    }
    private void bind()
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["web"]);//创建连接对象
        string ValidateStr = "select max(Score) as score from SC where Cno='" + ddlCourse.SelectedValue + "' and Teaid='" + Session["Username"].ToString() + "'";
        if (conn.State.ToString() == "Closed")              //连接如果关闭，打开
            conn.Open();

        SqlCommand cmd = new SqlCommand(ValidateStr, conn);  //创建操作数据库对象
        SqlDataReader sdr = cmd.ExecuteReader();            //执行查询
        if (sdr.Read())
        {
            if (sdr["score"].ToString() != "")   //判断成绩是否提交
            {
                GridView1.Visible = false;
                Response.Write("<script language=javascript>alert('该课程成绩已经提交，不能再次提交！');window.location.href='teacher.aspx';</script>");
               
                
            }
            else
            {
                sdr.Close();
                GridView1.Visible = true;
                string SqlStr = "SELECT student.*,SC.* FROM Student ,SC where Student.Sno=SC.Sno and SC.Cno='" + ddlCourse.SelectedValue + "'order by Student.Sno, Student.Grade,Student.Class";
                DataSet ds = new DataSet();
                try
                {
                    if (conn.State.ToString() == "Closed")          //连接如果关闭，打开
                        conn.Open();
                    SqlDataAdapter da = new SqlDataAdapter(SqlStr, conn);
                    da.Fill(ds);                                    //向DataSet数据集填充数据

                    GridView1.DataSource = ds.Tables[0].DefaultView;//为GridView指名数据源
                    GridView1.DataBind();                           //绑定数据
                }
                catch (Exception ex)                                //异常处理
                {
                    Response.Write("数据库错误，错误原因：" + ex.Message);
                    Response.End();
                }
                finally
                {
                    if (conn.State.ToString() == "Open")            //如果连接打开，关闭
                        conn.Close();
                    //}
                }
            }

        }
    }
    private void BindDDL()
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["web"]);
        string SqlStr = "SELECT distinct Course.Cno,Course.Cname from SC,Course where SC.Cno=Course.Cno and SC.Teaid='" + Session["userName"].ToString() + "'";
        DataSet ds = new DataSet();
        if (conn.State.ToString() == "Closed")              //如果连接关闭,打开
            conn.Open();
        SqlDataAdapter da = new SqlDataAdapter(SqlStr, conn);
        da.Fill(ds);                                        //从数据库中取数据放到DataSet数据集中
        if (conn.State.ToString() == "Open")
            conn.Close();

        ddlCourse.DataSource = ds.Tables[0].DefaultView;
        ddlCourse.DataTextField = "Cname";             //下拉列表框每项显示课程名称
        ddlCourse.DataValueField = "Cno";              //下拉列表框每项的值为课程编号
        ddlCourse.DataBind();
    }
    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["web"]);
        string strUpdate = "";
        int score;
        string stuID = "";
        string courceID = ddlCourse.SelectedValue;      //课程编号
        int flag = 0;                                     //标志
        string Teaid = Session["Username"].ToString();
        if (conn.State.ToString() == "Closed")          //连接如果关闭，打开
            conn.Open();
        int i;
        for (i = 0; i < GridView1.Rows.Count; i++)
        {
            score = int.Parse(((TextBox)GridView1.Rows[i].FindControl("txtScore")).Text.Trim());//取出学生成绩
            stuID = GridView1.Rows[i].Cells[0].Text;
            strUpdate = "update SC set Score=" + score + " where Sno='" + stuID + "' and Cno='" + courceID + "' and Teaid='" + Teaid + "'";
            try
            {
                SqlCommand cmd = new SqlCommand(strUpdate, conn);//创建Command对象
                flag = cmd.ExecuteNonQuery();                   //执行添加成绩操作
            }
            catch (Exception ex)                                //异常处理
            {
                Response.Write("数据库错误，错误原因：" + ex.Message);
                Response.End();
            }
        }
        if (conn.State.ToString() == "Open")            //如果连接打开，关闭
            conn.Close();
        if ((flag == 1) && (i == GridView1.Rows.Count))
        {
            Response.Write("成功录入学生成绩！此后将不能再修改！");
            Response.Redirect("teacher.aspx");
        }
    }
    protected void ddlCourse_SelectedIndexChanged(object sender, EventArgs e)
    {
        bind();
    }
}