为什么我的查询无法正常工作？

Question

您好我用这个查询更新我的数据库，但不工作：

if (Request["mode"] != null) 
     { 
      Int32 ID = Int32.Parse(Request["Id"].ToString()); 
      using (NoavaranModel.NoavaranEntities1 dbContext = new NoavaranModel.NoavaranEntities1()) 
      { 
       var ToEdit = (from n in dbContext.Packages 
            where n.Id == ID 
            select n).FirstOrDefault(); 
       ToEdit.Name = txtName.Text; 
       ToEdit.Level = txtLevel.Text; 
       ToEdit.Description = txtDescription.Text; 
       ToEdit.ForAge = ddlAgeFor.SelectedItem.Text; 
       ToEdit.CatId = ddlCategory.SelectedIndex + 1; 
       dbContext.SaveChanges(); 
       //Response.Redirect("Packages.aspx"); 
       //return;*/ 
      } 
     } 

Answer 1

我解决我的问题，我是忘记了我使用的IsPostBack：

if (!IsPostBack) 
     { 
      if (Request["Id"] != null) 
      { 
       Int32 ID = Int32.Parse(Request["Id"].ToString()); 
       using (NoavaranModel.NoavaranEntities1 dbContext = new NoavaranModel.NoavaranEntities1()) 
       { 
        var query = (from list in dbContext.Packages 
           where list.Id == ID 
           select list).FirstOrDefault(); 
        txtName.Text = query.Name; 
        txtLevel.Text = query.Level; 
        txtDescription.Text = query.Description; 
        Image2.ImageUrl = "PackageImages/" + query.Image; 
        ddlAgeFor.Text = query.ForAge; 
        //ddlCategory.Text = query.CatId.ToString(); 
       } 
      } 
     } 

Answer 2

尝试增加SaveOptions.DetectChangesBeforeSave参数SaveChanges()：

dbContext.SaveChanges(SaveOptions.DetectChangesBeforeSave);