protected void GridViewBind()
    {
        MultiProblem multiproblem = new MultiProblem();                                                 //创建多选题对象
        DataSet      ds           = multiproblem.QueryMultiProblem(int.Parse(ddlCourse.SelectedValue)); //根据试卷科目查询多选题信息

        GridView1.DataSource = ds.Tables[0].DefaultView;                                                //为GridView控件指名数据源
        GridView1.DataBind();                                                                           //绑定数据
    }