使用linq选择冒号值

本文关键字：选择 linq 使用 | 更新日期: 2023-09-27 18:08:06

我想选择一个冒号具有where条件的值(它从idlist的值变成)。然后这些值将被添加到列表中。我试过的代码如下。

怎么做?

public ActionResult Create(string UrunId, List<String> idlist)
{
       List<String> fiyatList = new List<string>();
       if (idlist != null)
       {
           ViewBag.abc = idlist;
           int i;
           for(i=0;i<idlist.Count();i++)
           {
               var sorgu = from a in db.Urunlers where a.UrunId == Int32.Parse(idlist[i]) select new { a.UrunFiyat};
               fiyatList.Add(sorgu.ToString());
           }
           ViewBag.fiyat = fiyatList;
        }
        return View();
}

但是返回的是查询而不是值

<<p> UrunList视图/strong> 
@foreach (BillApplication.Models.Urunler con in Model)
        {
            <tr>
                <td>
                    <input id="urunsec" type="checkbox" name="cbList" value="@con.UrunId.ToString()" onchange="ClickMe(this)" />
                </td>
                <td>@con.UrunId</td>
                <td>@con.UrunAdi</td>
                <td><div id="=fiyatdiv"> @con.UrunFiyat </div></td>
                <td>@con.AltkategoriId</td>
                <td colspan="4"></td>
            </tr>
        }
        <tr>
            <td>
                <input id="submit" type="submit" value="Gönder" name="Command" />
            </td>
        </tr>
<<p> 创建视图/strong> 
 <td>
                <textarea id="txt_urunler" rows="2" cols="20" style="border-style:inset; width:150px; border-width:0.2em; border-color:gainsboro">
                    @if (@ViewBag.abc != null)
                    {
                        foreach (var i in ViewBag.abc)
                        {
                            @i
                        }
                    }
                </textarea>
            </td>
            <td>
                <textarea id="txt_fiyat" rows="2" cols="20" style="border-style:inset; width:150px; border-width:0.2em; border-color:gainsboro">
                    @if (@ViewBag.fiyat != null)
                    {
                        foreach (var i in ViewBag.fiyat)
                        {
                            @i
                        }
                    }
                </textarea>
            </td>

创建动作

public ActionResult Create(string UrunId, List<String> idlist, List<String> fiyatList)
    {
       if (idlist != null)
        {
            ViewBag.abc = idlist;
        }
       if (fiyatList != null)
       {
           ViewBag.fiyat = fiyatList;
       }
           return View();
    }
    [HttpPost]
    public ActionResult Create(Faturalar mReg, string Command, string txt_cari)
    {
        if (Command == "hesapla") { }
        else if (Command == "Ürün Seç") { return RedirectToAction("UrunList"); }

        return View();
    }

使用linq选择冒号值

您不应该创建额外的对象，在本例中(sorgu)

你正在创建一个sorgu，它不会被用来做任何进一步的计算。

for(i = 0; i < idlist.Count(); i++)
{ 
     fiyatList.Add(db.Urunlers.Where(a => a.UrunId == int.Parse(idlist[i])
                     .FirstOrDefault()).ToString()); 
}

为干净的代码创建一个lambda。这是你的选择。

你也应该使用Model而不是ViewBag。

试试这个

foreach(var item in idlist)
{
     int reqInt;
     if(!int.TryParse(item.Trim(), out reqInt)
     {
         throw new Exception("Invalid Value");
     }
     var sorgu = (from a in db.Urunlers 
                 where a.UrunId == reqInt 
                 select a.UrunFiyat).FirstOrDefault();
     fiyatList.Add(sorgu.ToString());
}

或

var finalList = db.Urunlers.Where(x => idlist.Select(int.Parse).ToList().Contains(x.UrunId)).Select(v => v.UrunFiyat).ToList();
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