Question

我是MVC和软件开发的新手，我想在我的应用程序中实现按日期搜索功能。在索引视图中，我希望用户能够通过网页上提供的两个日期字段进行搜索，＆＃34;日期＆＃34;和＆＃34;订单日期＆＃34;。目前这是我在视图中的代码，它基本上指定了页面的布局。

using (Html.BeginForm("Index","PurchaseOrder",FormMethod.Get))
{
    <p>
        Search by Date: &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;@Html.TextBox("searchBy","dateSearchBegin") to: @Html.TextBox("searchBy","dateSearchEnd")
        <input type="submit" value="Search" /> <br /><br />
        Search by Order Date: &nbsp;@Html.TextBox("searchBy","dateOrderedBegin") to: @Html.TextBox("searchBy","dateOrderedEnd")
        <input type="submit"  value="Search" />
        <br /> <br />
        Search by: @Html.RadioButton("searchBy","Requestor", true) Requestor
        @Html.RadioButton("searchBy","Vendor") Vendor
        @Html.RadioButton("searchBy","workOrder") Work Order # <br />
        @Html.TextBox("search","", new { style = "width:10000px" })
        <input type="submit" value="Search"  />
    </p>

}

在控制器中，我有这个代码。这是我试图提供能够按不同字段过滤的逻辑。

// GET: PurchaseOrder
public ActionResult Index(string searchBy, string search,  int? page)
{

    if (searchBy == "Requestor")
    {
        return View(db.PurchaseOrders.Where(x => x.Requestor.ToUpper().Contains(search)).OrderBy(i => i.DateOrdered).ToPagedList(page ?? 1, 15));
    }
    else if (searchBy == "Vendor")
    {
        return View(db.PurchaseOrders.Where(x => x.Vendor.ToUpper().Contains(search)).OrderBy(i=>i.DateOrdered).ToPagedList(page??1,15));
    }
    else if (searchBy == "workOrder")
    {
        return View(db.PurchaseOrders.Where(x => x.PurchaseRequest_.ToUpper().Contains(search)).OrderBy(i => i.DateOrdered).ToPagedList(page ?? 1, 15));
    }
    else if (searchBy == "dateSearchBegin")
    {
        return View(db.PurchaseOrders.Where(x => x.Date > "dateSearchBegin" && x.Date < "dateSearchEnd").OrderBy(i => i.Date).ToPagedList(page ?? 1,15));
    }
    else if (searchBy == "dateSearchEnd")
    {
        return View(db.PurchaseOrders.Where(x => x.Date > "dateOrderedBegin" && x.Date < "dateOrderedEnd").OrderBy(i => i.Date).ToPagedList(page ?? 1,15));
    }
    int pageSize = 15;
    int pageNumber = (page ?? 1);
    pageNumber = page == null ? (ViewBag.pageData == null ? 1 : (int)ViewBag.pageData) : page.Value;
    ViewBag.pageData = page;
    return View(db.PurchaseOrders.OrderBy(i => i.DateOrdered).ToPagedList(pageNumber, pageSize));
}

我收到一条错误消息，指出＆＃34;运营商＆＃39;＆lt;＆＃39;不能应用于类型＆＃39; System.DateTime？＆＃39;的操作数？和＆＃39;字符串＆＃39;。我该如何解决这个错误，是否有更有效的方法对其进行编码以实现我的目标？

Answer 1

您需要从查询（DateTime）构造string search对象，然后在linq查询中使用它。

var dtFrom = DateTime.Parse(search)
var dtTo ...

return View(db.PurchaseOrders.Where(x => x.Date > dtFrom && x.Date < dtTo).OrderBy(i => i.Date).ToPagedList(page ?? 1,15));

但您还需要引入一次性搜索多个属性的功能。您只需从linq查询中返回IQueryable并对其进行后续查询即可实现此目的。这样您就可以连接多个查询：

var filtered = db.PurchaseOrders.Where(x => ...).AsQueryable(); 
filtered = filtered.Where(x => ...).AsQueryable();

等

然后返回

filtered.ToPagedList()

如何在ASP.NET Web应用程序中的日期之间进行筛选

1 个答案: