使用多个搜索字符串 ASP.NET Core Visual Studio 2017 添加分页链接到视图 - 搜索字符串未被接管

Question

我正在开发一个参考示例的分页索引视图 Sorting, filtering, paging, and grouping - EF Core with ASP.NET Core MVC tutorial (3 of 10)

在我的索引页面上，我使用了 3 个搜索字符串。

排序效果很好，但没有搜索参数。一旦我在输入搜索字符串后尝试排序，就没有任何效果。应该接管搜索字符串。它没有发生。

插入搜索字符串后的分页也无法正常工作。名为 CurrentFilterxxx 的 ViewData 元素为视图提供了当前过滤器字符串。该值必须包含在分页链接中，以便在分页期间保持过滤器设置，并且必须在重新显示页面时将其恢复到文本框中。就我而言，它不起作用。

这里是控制器的索引方法Class:

public async Task<IActionResult> Index(
        string sortOrder, 
        string searchStringComune, 
        string searchStringProvincia, 
        string searchStringRegione,
        string searchString,
        string currentFilter,
        int? page)
    {
        ViewData["CurrentSort"] = sortOrder;
        ViewData["ComuneSortParm"] = String.IsNullOrEmpty(sortOrder) ? "comune" : "";
        ViewData["ProvinciaSortParm"] = String.IsNullOrEmpty(sortOrder) ? "provincia" : "";
        ViewData["RegioneSortParm"] = String.IsNullOrEmpty(sortOrder) ? "regione" : "";
        ViewData["PostalCodeSortParm"] = String.IsNullOrEmpty(sortOrder) ? "CAP" : "";
        ViewData["AbitantsSortParm"] = String.IsNullOrEmpty(sortOrder) ? "abitanti" : "";

        if (searchStringComune != null ||
            searchStringProvincia != null ||
            searchStringRegione != null ||
            searchString != null)
        {
            page = 1;
            if (searchStringComune != null)
            {
                searchString = searchStringComune;
            }
            if (searchStringProvincia != null)
            {
                searchString = searchStringProvincia;
            }
            if (searchStringRegione != null)
            {
                searchString = searchStringRegione;
            }
        }
        else
        {
            searchString = currentFilter;
        }

        ViewData["CurrentFilterComune"] = searchStringComune;
        ViewData["CurrentFilterProvincia"] = searchStringProvincia;
        ViewData["CurrentFilterRegione"] = searchStringRegione;
        ViewData["CurrentFilter"] = searchString;

        var comuni = from s in _context.Listacomuniitaliani
                       select s;

        if (!String.IsNullOrEmpty(searchStringComune) ||
            !String.IsNullOrEmpty(searchStringProvincia) ||
            !String.IsNullOrEmpty(searchStringRegione))
        {

            comuni = comuni.Where(s => s.Comune.Equals(searchStringComune) ||
                                       s.Provincia.Equals(searchStringProvincia) ||
                                       s.Regione.Equals(searchStringRegione));
        }

        switch (sortOrder)
        {
            case "comune":
                comuni = comuni.OrderByDescending(s => s.Comune);
                break;
            case "provincia":
                comuni = comuni.OrderBy(s => s.Provincia);
                break;
            case "regione":
                comuni = comuni.OrderBy(s => s.Regione);
                break;
            case "CAP":
                comuni = comuni.OrderBy(s => s.Cap);
                break;
            case "abitanti":
                comuni = comuni.OrderBy(s => s.Abitanti);
                break;
            default:
                comuni = comuni.OrderBy(s => s.Comune);
                break;
        }

        int pageSize = 7;
        return View(await PaginatedList<Listacomuniitaliani>.CreateAsync(comuni.AsNoTracking(), page ?? 1, pageSize));
    }

这是我的索引代码：

@model PaginatedList<MyProjectName.Models.Listacomuniitaliani>

@{ViewData["Title"] = "Index";}

<h2>Index</h2>

<p>
<a asp-action="Create">Create New</a>
</p>

<form asp-action="Index" method="get">
    <div class="form-actions no-color">
        <p>
            Cerca un comune: <input type="text" name="SearchStringComune" value="@ViewData["currentFilterComune"]" />
            <input type="submit" value="trova" class="btn btn-default" />
        </p>
    </div>
</form>

<form asp-action="Index" method="get">
<div class="form-actions no-color">
    <p>
        Seleziona una provincia: <input type="text" name="SearchStringProvincia" value="@ViewData["currentFilterProvincia"]" />
        <input type="submit" value="trova" class="btn btn-default" />
    </p>
</div>

<form asp-action="Index" method="get">
<div class="form-actions no-color">
    <p>
        Seleziona una regione: <input type="text" name="SearchStringRegione" value="@ViewData["currentFilterRegione"]" />
        <input type="submit" value="trova" class="btn btn-default" />
    </p>
</div>

<form asp-action="Index" method="get">
<div class="form-actions no-color">
    <p>
        <a asp-action="Index">Torna indietro alla lista</a>
    </p>
</div>

<table class="table">
<thead>
    <tr>
            <th>
                Istat
            </th>
            <th>
                    <a asp-action="Index" asp-route-sortOrder="@ViewData["ComuneSortParm"]"
                       asp-route-currentFilterComune="@ViewData["CurrentFilterComune"]">Comune</a>                       
    </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["ProvinciaSortParm"]"
                   asp-route-currentFilterProvincia="@ViewData["CurrentFilterProvincia"]">Provincia</a>
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["RegioneSortParm"]"
                   asp-route-currentFilterRegione="@ViewData["CurrentFilterRegione"]">Regione</a>
            </th>
            <th>
                Prefisso
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["PostalCodeSortParm"]">CAP</a>
            </th>
            <th>
                CodFisco
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["AbitantsSortParm"]">Abitanti</a>
            </th>
            <th>
                Link
            </th>
        <th></th>
    </tr>
</thead>
<tbody>
@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Istat)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Comune)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Provincia)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Regione)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Prefisso)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Cap)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.CodFisco)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Abitanti)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Link)
        </td>
        <td>
            <a asp-action="Edit" asp-route-id="@item.Id">Edit</a> |
            <a asp-action="Details" asp-route-id="@item.Id">Details</a> |
            <a asp-action="Delete" asp-route-id="@item.Id">Delete</a>
        </td>
    </tr>
     }
</tbody>
</table>

@{
var prevDisabled = !Model.HasPreviousPage ? "disabled" : "";
var nextDisabled = !Model.HasNextPage ? "disabled" : "";
}


<a asp-action="Index"
asp-route-sortOrder="@ViewData["CurrentSort"]"
asp-route-page="@(Model.PageIndex - 1)"
@*asp-route-currentFilter="@ViewData["CurrentFilter"]"*@
asp-route-currentFilterComune="@ViewData["CurrentFilterComune"]"
asp-route-currentFilterRegione="@ViewData["CurrentFilterRegione"]"
asp-route-currentFilterProvincia="@ViewData["CurrentFilterProvincia"]"
class="btn btn-default @prevDisabled">
Previous
</a>

<a asp-action="Index"
asp-route-sortOrder="@ViewData["CurrentSort"]"
asp-route-page="@(Model.PageIndex + 1)"
@*asp-route-currentFilter="@ViewData["CurrentFilter"]"*@
asp-route-currentFilterComune="@ViewData["CurrentFilterComune"]"
asp-route-currentFilterRegione="@ViewData["CurrentFilterRegione"]"
asp-route-currentFilterProvincia="@ViewData["CurrentFilterProvincia"]"
class="btn btn-default ifextDisabled">
Next
</a>

标签助手 asp-route-currentFilter 还没有 used.Instead，我使用了更具体的标签助手；例如 asp-route-currentFilterComune.

感谢任何帮助。

Answer 1

我已经开始工作了。为此，我必须重新设计控制器的一部分并对视图代码进行一些修改。处理多个搜索字符串对我来说非常具有挑战性。

这是我的新控制器索引方法：

public async Task<IActionResult> Index(
        string sortOrder, 
        string searchStringComune, 
        string searchStringProvincia, 
        string searchStringRegione,
        string searchString,
        string currentFilter,
        int? page)
    {
        ViewData["CurrentSort"] = sortOrder;
        ViewData["ComuneSortParm"] = String.IsNullOrEmpty(sortOrder) ? "comune" : "";
        ViewData["ProvinciaSortParm"] = String.IsNullOrEmpty(sortOrder) ? "provincia" : "";
        ViewData["RegioneSortParm"] = String.IsNullOrEmpty(sortOrder) ? "regione" : "";
        ViewData["PostalCodeSortParm"] = String.IsNullOrEmpty(sortOrder) ? "CAP" : "";
        ViewData["AbitantsSortParm"] = String.IsNullOrEmpty(sortOrder) ? "abitanti" : "";


        if (searchStringComune != null ||
            searchStringProvincia != null ||
            searchStringRegione != null ||
            searchString != null)
        {
            page = 1;
        }
        else
        {
            searchStringProvincia = currentFilter;
            searchStringRegione = currentFilter;

            foreach (ItalianRegions itemRegion in Enum.GetValues(typeof(ItalianRegions)))
            {
                if (searchStringRegione == itemRegion.ToString())
                {
                    searchStringProvincia = null;
                }
            }

            foreach (ItalianComunes itemComune in Enum.GetValues(typeof(ItalianComunes)))
            {
                if (searchStringProvincia == itemComune.ToString())
                {
                    searchStringRegione = null;
                }
            }

        }


        ViewData["CurrentFilterComune"] = searchStringComune;
        ViewData["CurrentFilterProvincia"] = searchStringProvincia;
        ViewData["CurrentFilterRegione"] = searchStringRegione;
        ViewData["CurrentFilter"] = searchString;

        var comuni = from s in _context.Listacomuniitaliani
                       select s;

        if (!String.IsNullOrEmpty(searchStringComune) ||
            !String.IsNullOrEmpty(searchStringProvincia) ||
            !String.IsNullOrEmpty(searchStringRegione))
        {
            comuni = comuni.Where(s => s.Comune.Equals(searchStringComune) ||
                                       s.Provincia.Equals(searchStringProvincia) ||
                                       s.Regione.Equals(searchStringRegione));
        }

        switch (sortOrder)
        {
            case "comune":
                comuni = comuni.OrderByDescending(s => s.Comune);
                break;
            case "provincia":
                comuni = comuni.OrderBy(s => s.Provincia);
                break;
            case "regione":
                comuni = comuni.OrderBy(s => s.Regione);
                break;
            case "CAP":
                comuni = comuni.OrderBy(s => s.Cap);
                break;
            case "abitanti":
                comuni = comuni.OrderBy(s => s.Abitanti);
                break;
            default:
                comuni = comuni.OrderBy(s => s.Comune);
                break;
        }


        int pageSize = 7;
        return View(await PaginatedList<Listacomuniitaliani>.CreateAsync(comuni.AsNoTracking(), page ?? 1, pageSize));
    }

我已经使用 2 个不同的 enum 循环进入搜索字符串，以便能够在分页时正确设置搜索字段中的搜索字符串文本。

这里是 Index 代码：

@model PaginatedList<MyProject.Models.Listacomuniitaliani>

@{
 ViewData["Title"] = "Index";
}

<h2>Index</h2>

<p>
 <a asp-action="Create">Create New</a>
</p>

<form asp-action="Index" method="get">
    <div class="form-actions no-color">
        <p>
            Cerca un comune: <input type="text" name="searchStringComune"    value="@ViewData["CurrentFilterComune"]" />
            <input type="submit" value="trova" class="btn btn-default" />
        </p>
    </div>
</form>


<form asp-action="Index" method="get">
 <div class="form-actions no-color">
    <p>
        Seleziona una provincia: <input type="text" name="searchStringProvincia" value="@ViewData["CurrentFilterProvincia"]" />
        <input type="submit" value="trova" class="btn btn-default" />
    </p>
  </div>
</form>

<form asp-action="Index" method="get">
  <div class="form-actions no-color">
    <p>
        Seleziona una regione: <input type="text" name="searchStringRegione" value="@ViewData["CurrentFilterRegione"]" />
        <input type="submit" value="trova" class="btn btn-default" />
    </p>
  </div>
</form>

<form asp-action="Index" method="get">
  <div class="form-actions no-color">
    <p>
        <a asp-action="Index">Torna indietro alla lista</a>
    </p>
  </div>
 </form>


 <table class="table">
  <thead>
    <tr>
            <th>
                Istat
            </th>
            <th>
                    <a asp-action="Index" asp-route-sortOrder="@ViewData["ComuneSortParm"]">Comune</a>
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["ProvinciaSortParm"]"
                   asp-route-currentFilter="@ViewData["CurrentFilterProvincia"]">Provincia</a>
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["RegioneSortParm"]"
                   asp-route-currentFilter="@ViewData["CurrentFilterRegione"]">Regione</a>
            </th>
            <th>
                Prefisso
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["PostalCodeSortParm"]">CAP</a>
            </th>
            <th>
                CodFisco
            </th>
            <th>
                <a asp-action="Index" asp-route-sortOrder="@ViewData["AbitantsSortParm"]">Abitanti</a>
            </th>
            <th>
                Link
            </th>
        <th></th>
     </tr>
    </thead>
  <tbody>

   @foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Istat)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Comune)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Provincia)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Regione)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Prefisso)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Cap)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.CodFisco)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Abitanti)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Link)
        </td>
        <td>
            <a asp-action="Edit" asp-route-id="@item.Id">Edit</a> |
            <a asp-action="Details" asp-route-id="@item.Id">Details</a> |
            <a asp-action="Delete" asp-route-id="@item.Id">Delete</a>
        </td>
    </tr>
     }
   </tbody>
  </table>

   @{
     var prevDisabled = !Model.HasPreviousPage ? "disabled" : "";
     var nextDisabled = !Model.HasNextPage ? "disabled" : "";
    }


 <a asp-action="Index"
    asp-route-sortOrder="@ViewData["CurrentSort"]"
    asp-route-page="@(Model.PageIndex - 1)"
    asp-route-currentFilter=@if (@ViewData["CurrentFilterRegione"] != null)
    {
      @ViewData["CurrentFilterRegione"]
    } else
    {
      @ViewData["CurrentFilterProvincia"]
    }
    class="btn btn-default @prevDisabled">
    Previous
 </a>
 <a asp-action="Index"
    asp-route-sortOrder="@ViewData["CurrentSort"]"
    asp-route-page="@(Model.PageIndex + 1)"
    asp-route-currentFilter=@if (@ViewData["CurrentFilterRegione"] != null)
    {
      @ViewData["CurrentFilterRegione"]
    } else
    {
    @ViewData["CurrentFilterProvincia"]
    }
    class="btn btn-default @nextDisabled">
    Next
</a>

现在可以完美运行了。排序工作。分页也有效，维护搜索字符串文本。

使用多个搜索字符串 ASP.NET Core Visual Studio 2017 添加分页链接到视图 - 搜索字符串未被接管

Add paging links to View using multiple search strings ASP.NET Core Visual Studio 2017 - search string is not taken over

razor

entity-framework-core

asp.net-core-mvc

visual-studio-2017

asp.net-core-1.1