Question

我有一个IEnumerable View.this视图页面（cshtml）包含一个模型数据和一些form.it列出数据的所有数据。我想通过多个过滤器选项过滤这些数据，例如按城市，区域，楼层，道路过滤，没有e.t.c所有那些过滤器都在我的表格字段中。我的动作如下：



                                                                                            [HttpPost]
  public ViewResult SearchPost()
      {

        var posts =db.posts.Include("user").ToList();

        if (Request.Form["searchString"] != null)
        {
           posts = (from posts in db.posts where posts.area   
           ==Request .Form["searchString"]).ToList();                      
        }
         if (Request.Form["searchString2"] != null)
        {
            posts = (from posts in db.posts where posts.city 
            ==Request.Form["searchString2"]).ToList();
        }
          if (Request.Form["searchString3"] != null)
        {
            posts = (from posts in db.posts where posts.floor 
            ==Request.Form["searchString3"]).ToList();
        }


        return View(posts);
       }

[HttpPost] public ViewResult SearchPost() { var posts =db.posts.Include("user").ToList(); if (Request.Form["searchString"] != null) { posts = (from posts in db.posts where posts.area ==Request .Form["searchString"]).ToList(); } if (Request.Form["searchString2"] != null) { posts = (from posts in db.posts where posts.city ==Request.Form["searchString2"]).ToList(); } if (Request.Form["searchString3"] != null) { posts = (from posts in db.posts where posts.floor ==Request.Form["searchString3"]).ToList(); } return View(posts); }

我的观看页面：

   @using (Html.BeginForm()){   
     <p> Area: @Html.TextBox("SearchString") 
     <p> City: @Html.TextBox("SearchString2") 
     <p> Floor: @Html.TextBox("SearchString3") 
     <input type="submit" value="Filter" /></p>
    }


   >.....list of Model Data

我的所有过滤器选项都是可选的。可以选择一个或多个过滤器选项，或者可以不选择它们。它给出错误范围变量帖子我希望在每个if条件块中过滤我的结果集。可能吗？？？如果可能的话请给我一些想法.....提前致谢

Answer 1

检查null＆amp;＆amp;＆amp;运行查询之前的任何（）结果。过滤器1和/或2可能会排除您的所有结果。

if (Request.Form["searchString"] != null)          
{
    if ((posts!=null) && (posts.Any()))
         {
                posts = (from posts in db.posts where posts.area
                ==Request .Form["searchString"]).ToList();                                
         }
}           
if (Request.Form["searchString2"] != null)          
{              
    if ((posts!=null) && (posts.Any()))   
         {
                posts = (from posts in db.posts where posts.area
                ==Request .Form["searchString2"]).ToList();                                
         }
}            
if (Request.Form["searchString3"] != null)          
{
    if ((posts!=null) && (posts.Any()))   
         {
                posts = (from posts in db.posts where posts.area
                ==Request .Form["searchString3"]).ToList();                                
         }
}

在asp.net mvc3中过滤结果集

1 个答案: