C# s、 GroupID=g.GroupID 选择new{//您可以定义一个模型视图，其中包含您想要的任何属性，但我假设您需要以下内容 Nume=s.名称， Prenume=s.Prenume， Nota=s.Nota， GrupaID=g.Name，//在这里输入组的名称 ConducatorID=s.ConducatorID， TPracticaID=s.TPracticaID， Periodaid=s.Periodaid， StudentID=StudentID， }; var gv=新的GridView（）； gv.DataSource=result.ToList（）；//你把结果放在这里 gv.DataBind（）； Response.ClearContent（）； Response.Buffer=true； AddHeader（“内容处置”、“附件；文件名=DemoExcel.xls”）； Response.ContentType=“应用程序/ms excel”； 响应。Charset=“”； StringWriter objStringWriter=新StringWriter（）； HtmlTextWriter objHtmlTextWriter=新的HtmlTextWriter（objStringWriter）； gv.渲染控制（objHtmlTextWriter）； Response.Output.Write（objStringWriter.ToString（））； Response.Flush（）； Response.End（）； }

希望这将对您有所帮助

这是上述问题的解决方案：

public void ExportToExcel(string grupString)
       {
            var student = (List<Student>)Session["student"];
            var groups = db.Grupa.ToList();
            var result = (from e in student
                          select new
                          {
                              Nume = e.Nume,
                              Prenume = e.Prenume,
                              Nota = e.Nota,
                              Grupa = e.Grupa.Specialitate + " " + e.Grupa.Numar,
                              Conducator = e.Conducator.Nume+" "+ e.Conducator.Prenume,
                              Tpractica = e.Tpractica.Tip,
                              Perioada = e.Perioada.An,
                              LocPractica = e.LocPractica.Denumire,
                          }).ToList();



            var gv = new GridView();

            gv.DataSource = result;


            gv.DataBind();


            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=DemoExcel.xls");
            Response.ContentType = "application/ms-excel";

            Response.Charset = "";
            StringWriter objStringWriter = new StringWriter();
            HtmlTextWriter objHtmlTextWriter = new HtmlTextWriter(objStringWriter);

            gv.RenderControl(objHtmlTextWriter);

            Response.Output.Write(objStringWriter.ToString());
            Response.Flush();
            Response.End();



        }

public void ExportToExcel（字符串grupString）
{
var student=（列表）会话[“student”]；
var groups=db.Grupa.ToList（）；
var结果=（来自学生中的e）
选择新的
{
努姆，
Prenume=e.Prenume，
Nota=e.Nota，
Grupa=e.Grupa.Specialitate+“”+e.Grupa.Numar，
Conducator=e.Conducator.Nume+“”+e.Conducator.Prenume，
tpracica=e.tpracica.Tip，
perioda=e.perioda.An，
Locpreaca=e.Locpreaca.Denumire，
}).ToList（）；
var gv=新的GridView（）；
gv.DataSource=结果；
gv.DataBind（）；
Response.ClearContent（）；
Response.Buffer=true；
AddHeader（“内容处置”、“附件；文件名=DemoExcel.xls”）；
Response.ContentType=“应用程序/ms excel”；
响应。Charset=“”；
StringWriter objStringWriter=新StringWriter（）；
HtmlTextWriter objHtmlTextWriter=新的HtmlTextWriter（objStringWriter）；
gv.渲染控制（objHtmlTextWriter）；
Response.Output.Write（objStringWriter.ToString（））；
Response.Flush（）；
Response.End（）；
}

我可以导出所有数据并过滤到excel

---

感谢哈迪·哈桑的帮助。

这是上述问题的解决方案：

public void ExportToExcel(string grupString)
       {
            var student = (List<Student>)Session["student"];
            var groups = db.Grupa.ToList();
            var result = (from e in student
                          select new
                          {
                              Nume = e.Nume,
                              Prenume = e.Prenume,
                              Nota = e.Nota,
                              Grupa = e.Grupa.Specialitate + " " + e.Grupa.Numar,
                              Conducator = e.Conducator.Nume+" "+ e.Conducator.Prenume,
                              Tpractica = e.Tpractica.Tip,
                              Perioada = e.Perioada.An,
                              LocPractica = e.LocPractica.Denumire,
                          }).ToList();



            var gv = new GridView();

            gv.DataSource = result;


            gv.DataBind();


            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=DemoExcel.xls");
            Response.ContentType = "application/ms-excel";

            Response.Charset = "";
            StringWriter objStringWriter = new StringWriter();
            HtmlTextWriter objHtmlTextWriter = new HtmlTextWriter(objStringWriter);

            gv.RenderControl(objHtmlTextWriter);

            Response.Output.Write(objStringWriter.ToString());
            Response.Flush();
            Response.End();



        }

public void ExportToExcel（字符串grupString）
{
var student=（列表）会话[“student”]；
var groups=db.Grupa.ToList（）；
var结果=（来自学生中的e）
选择新的
{
努姆，
Prenume=e.Prenume，
Nota=e.Nota，
Grupa=e.Grupa.Specialitate+“”+e.Grupa.Numar，
Conducator=e.Conducator.Nume+“”+e.Conducator.Prenume，
tpracica=e.tpracica.Tip，
perioda=e.perioda.An，
Locpreaca=e.Locpreaca.Denumire，
}).ToList（）；
var gv=新的GridView（）；
gv.DataSource=结果；
gv.DataBind（）；
Response.ClearContent（）；
Response.Buffer=true；
AddHeader（“内容处置”、“附件；文件名=DemoExcel.xls”）；
Response.ContentType=“应用程序/ms excel”；
响应。Charset=“”；
StringWriter objStringWriter=新StringWriter（）；
HtmlTextWriter objHtmlTextWriter=新的HtmlTextWriter（objStringWriter）；
gv.渲染控制（objHtmlTextWriter）；
Response.Output.Write（objStringWriter.ToString（））；
Response.Flush（）；
Response.End（）；
}

我可以导出所有数据并过滤到excel

---

感谢哈迪·哈桑的帮助。

受您回复的启发哈迪·哈桑，我修改了这样的代码，如果它对您有帮助，请将其标记为答案并投赞成票，谢谢您受您回复的启发哈迪·哈桑，我修改了这样的代码，如果它对您有帮助，请将其标记为答案并投赞成票，谢谢，请在我的答案旁边的复选标记上打勾并投上一票，因为这有助于你这样做，但我不能投票，因为我的代表数不足15。请在我的答案旁边的复选标记上打勾并投上一票，因为它有助于你这样做，但我不能投票，因为我的代表数不足15。

     if (!string.IsNullOrEmpty(grupString))
                {
    //Filter
                    student = student.Where(s => (s.Grupa.Specialitate + s.GrupaID).Contains(grupString));

                }
//Session storing student        
                Session["student"] = student.ToList<Student>(); ;
                return View(student);

public void ExportToExcel(string grupString)
       {
            var student = (List<Student>)Session["student"];



            var gv = new GridView();

           gv.DataSource =(from e in db.Student
                           select new 
                            {
                                Nume = e.Nume,
                                Prenume = e.Prenume,
                                Nota = e.Nota,
                                Grupa = e.Grupa.Specialitate+" "+e.Grupa.Numar,
/* The problem with cell space happens here ->**Conducator = e.Conducator.Nume+" "e.Conducator.Prenume ** when i try to make this cell made from adition of 2 string like i did before 
here **Grupa = e.Grupa.Specialitate+" "+e.Grupa.Numar,** -here the string are short and fit in the cell but when i try to do the same here 
 **Conducator = e.Conducator.Nume+" "e.Conducator.Prenume **, the strings are a little longer and throws and exception
 */
                                Conducator = e.Conducator.Nume, 
                                Tpractica = e.Tpractica.Tip,
                                Perioada =e.Perioada.An,
                                LocPractica= e.LocPractica.Denumire,
                               }
                               ).ToList(); 


            gv.DataBind();


            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=DemoExcel.xls");
            Response.ContentType = "application/ms-excel";

            Response.Charset = "";
            StringWriter objStringWriter = new StringWriter();
            HtmlTextWriter objHtmlTextWriter = new HtmlTextWriter(objStringWriter);

            gv.RenderControl(objHtmlTextWriter);

            Response.Output.Write(objStringWriter.ToString());
            Response.Flush();
            Response.End();       
        }

public void ExportToExcel()
        {
            var student = (List<Student>)Session["student"];
            var groups  = **YourDBContextGoesHere**.Groups.ToList();

            // extract new result from the student dbset and join it 
            // with groups dbset to get the name
            // Note: only one trip to the db to get the group names since
            //       the student already stored in the session
            var result  = from s in student
                          join g in groups on s.GroupID = g.GroupID
                          select new { // you can define a ModelView with whatever properties you want inside, but I will assume that you want the following
                             Nume = s.Name,
                             Prenume = s.Prenume,
                             Nota= s.Nota,
                             GrupaID = g.Name, // here you put the name of the group
                             ConducatorID =s.ConducatorID,
                             TPracticaID = s.TPracticaID,
                             PerioadaID = s.PerioadaID ,
                             StudentID = StudentID,
                          };
            var gv = new GridView();
            gv.DataSource =result.ToList(); // here you put the result
            gv.DataBind(); 

            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=DemoExcel.xls");
            Response.ContentType = "application/ms-excel";
            Response.Charset = "";
            StringWriter objStringWriter = new StringWriter();
            HtmlTextWriter objHtmlTextWriter = new HtmlTextWriter(objStringWriter);
            gv.RenderControl(objHtmlTextWriter);
            Response.Output.Write(objStringWriter.ToString());
            Response.Flush();
            Response.End();
        } 

public void ExportToExcel(string grupString)
       {
            var student = (List<Student>)Session["student"];
            var groups = db.Grupa.ToList();
            var result = (from e in student
                          select new
                          {
                              Nume = e.Nume,
                              Prenume = e.Prenume,
                              Nota = e.Nota,
                              Grupa = e.Grupa.Specialitate + " " + e.Grupa.Numar,
                              Conducator = e.Conducator.Nume+" "+ e.Conducator.Prenume,
                              Tpractica = e.Tpractica.Tip,
                              Perioada = e.Perioada.An,
                              LocPractica = e.LocPractica.Denumire,
                          }).ToList();



            var gv = new GridView();

            gv.DataSource = result;


            gv.DataBind();


            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=DemoExcel.xls");
            Response.ContentType = "application/ms-excel";

            Response.Charset = "";
            StringWriter objStringWriter = new StringWriter();
            HtmlTextWriter objHtmlTextWriter = new HtmlTextWriter(objStringWriter);

            gv.RenderControl(objHtmlTextWriter);

            Response.Output.Write(objStringWriter.ToString());
            Response.Flush();
            Response.End();



        }