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我有一个视图模型对象，其中包含另一个模型对象类型List。当用户在页面上进行查询时，如果返回的List包含超过300条记录，我们希望使用分页来减少加载时间（某些搜索结果可能会返回超过14k条记录）。我们正在使用的分页插件can be found here.无法创建接口的实例（PagedList）
一旦结果显示在页面上，用户就可以点击特定结果旁边的复选框，在输入文本框中键入一些信息，点击提交，并使用文本框中的信息编辑选定的记录。
因为我们需要的，以便使分页使用一个IPagedList<>，然而，当你点击提交（和之前的页面，甚至打控制器），我们得到以下错误：
Cannot create an instance of an interface.
视图模型
这些是我们用于分页的两个列表对象。 zipCodeTerritory对象保存查询的结果。 pagedTerritoryList用于仅显示用户所在的特定页面上的结果。
//Paging List objects
public IPagedList<ZipCodeTerritory> pagedTerritoryList { get; set; }
public List<ZipCodeTerritory> zipCodeTerritory { get; set; }
public IPagedList PagingMetaData { get; set; }
控制器
这是我们的基本搜索。 .ToPagedList方法用于指定我们要显示的结果范围，并将它们放在pagedTerritoryList对象中。
//set Paged List counter variables
int pageNumber = page ?? 1;
int pageSize = 300;
//Determine if Territory present?
if (string.IsNullOrWhiteSpace(search.searchTerritory))
{
//State Code ONLY search
search.zipCodeTerritory = (from z in db.ZipCodeTerritory
where z.StateCode.Equals(search.searchState)
select z).ToList();
}
else if(string.IsNullOrWhiteSpace(search.searchState))
{
//Territory ONLY search
search.zipCodeTerritory = (from z in db.ZipCodeTerritory
where z.IndDistrnId.Equals(search.searchTerritory)
select z).ToList();
}
else
{
//Territory AND state search
search.zipCodeTerritory = (from z in db.ZipCodeTerritory
where z.IndDistrnId.Equals(search.searchTerritory) &&
z.StateCode.Equals(search.searchState)
select z).ToList();
}
//Convert list to IPagedList for pagining on Index
search.pagedTerritoryList = search.zipCodeTerritory.ToPagedList(pageNumber, pageSize);
//Set Paged List objects
search.PagingMetaData = new StaticPagedList<ZipCodeTerritory>(search.zipCodeTerritory, pageNumber, pageSize,
search.zipCodeTerritory.Count).GetMetaData();
return View(search);
查看
这是一个显示搜索结果的形式。如果用户选中该复选框，然后点击clone或delete按钮，则结果应该被回送到控制器的Update方法并执行适当的编辑或删除。用户想要在编辑中叠加的信息以格式输入到newTerritory/Description/etc字段中（在table之上）。
关于@Html.PagedListPager我发现我不得不从页面传回给索引方法相同的搜索条件，因此RouteValueDictionary中的参数数量过大。
@if (Model.zipCodeTerritory.Count > 0)
{
using (Html.BeginForm("Update", "ZipCodeTerritory", FormMethod.Post))
{
@Html.HiddenFor(model => model.searchZip)
@Html.HiddenFor(model => model.searchDate)
@Html.HiddenFor(model => model.searchState)
<div id="cloneBox">
<div id="rw1">
@Html.LabelFor(model => model.newTerritory)
@Html.TextBoxFor(model => model.newTerritory, new { style = "width: 30px;padding-left:10px;", maxLength = 3 })
@Html.LabelFor(model => model.newDescription)
@Html.TextBoxFor(model => model.newDescription, new { style = "width: 250px;padding-left:10px;", maxLength = 30 })
@Html.LabelFor(model => model.newEffectiveDate)
@Html.TextBoxFor(model => model.newEffectiveDate, new { style = "width: 80px;padding-left:10px;" })
<div id="rw2" style="padding-top: 10px;">
@Html.LabelFor(model => model.newChannelCode)
@Html.DropDownListFor(model => model.newChannelCode, Model.ChannelCodes, " ")
@Html.LabelFor(model => model.newStateCode)
@Html.DropDownListFor(model => model.newStateCode, Model.StateCodes, " ")
</div>
</div>
</div>
<br/>
<div id="buttonDiv">
<button type="submit" id="CloneButton" name="button" value="clone">Apply New Data</button>
<button type="submit" id="deleteButton" name="button" value="delete">Delete Selected Items</button>
</div>
@*Display paging only if necessary*@
if (Model.pagedTerritoryList.Count >= 300)
{
<div id="pagingDiv">
@Html.PagedListPager(new StaticPagedList<Monet.Models.ZipCodeTerritory>(Model.zipCodeTerritory, Model.PagingMetaData) ,
Page => Url.Action("Index", new RouteValueDictionary()
{
{ "Page", Page},
{ "searchZip", Model.searchZip },
{ "searchActiveOnly", Model.searchActiveOnly },
{ "searchDate", Model.searchDate },
{ "searchState", Model.searchState },
{ "searchTerritory", Model.searchTerritory },
{ "searchChannel" , Model.searchChannelCode }
}), PagedListRenderOptions.DefaultPlusFirstAndLast)
</div>
}
<table id="thetable" class="tablesorter" >
<thead>
<th>@Html.CheckBox("SelectAll")</th>
<th>State</th>
<th>Territory</th>
<th>Zip</th>
<th>Description</th>
<th>Effective</th>
<th>End Date</th>
<th>Last Update Date</th>
<th>Channel</th>
<th></th>
</thead>
<tbody id="tableBody">
@for (int i = 0; i < Model.pagedTerritoryList.Count; i++)
{
<tr id="@(Model.lastEditedId == Model.pagedTerritoryList[i].Id ? "lastEdit" : "")">
<td>
@Html.CheckBoxFor(model => model.pagedTerritoryList[i].Update)
@Html.HiddenFor(model => model.pagedTerritoryList[i].Update)
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].StateCode)
@Html.HiddenFor(model => model.pagedTerritoryList[i].StateCode)
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].IndDistrnId)
@Html.HiddenFor(model => model.pagedTerritoryList[i].IndDistrnId)
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].ZipCode)
@Html.HiddenFor(model => model.zipCodeTerritory[i].ZipCode)
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].DrmTerrDesc)
@Html.HiddenFor(model => model.pagedTerritoryList[i].DrmTerrDesc)
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].EffectiveDate)
@Html.HiddenFor(model => model.pagedTerritoryList[i].EffectiveDate)
</td>
<td>
@if (Model.pagedTerritoryList[i].EndDate.Date != DateTime.MaxValue.Date)
{
@Html.DisplayFor(model => model.pagedTerritoryList[i].EndDate)
@Html.HiddenFor(model => model.pagedTerritoryList[i].EndDate)
}
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].LastUpdateDate)
@Html.HiddenFor(model => model.pagedTerritoryList[i].LastUpdateDate)
</td>
<td>
@Html.DisplayFor(model => model.pagedTerritoryList[i].ChannelCode)
@Html.HiddenFor(model => model.pagedTerritoryList[i].ChannelCode)
</td>
@if (ViewBag.SecurityLevel >= 4)
{
<td>
@Html.ActionLink("Edit", "Edit", new
{
id = Model.zipCodeTerritory[i].Id,
searchZip = Model.searchZip,
searchActiveOnly = Model.searchActiveOnly,
searchDate = Model.searchDate,
searchState = Model.searchState,
searchTerritory = Model.searchTerritory,
searchChannelCode = Model.searchChannelCode
})
@Html.HiddenFor(model => model.zipCodeTerritory[i].Id)
</td>
}
</tr>
}
</tbody>
</table>
}
}
编辑
每下面的评论，这里是形式发布给该方法的签名。它包含了获取网页上加载本来是ZipCodeIndex的实例，加上从button文本，以确定我们是否在做一个clone或delete
[HttpPost]
public ActionResult Update(ZipCodeIndex updateZip, string button)
{
第二个编辑
试过方法从this question，但仍然收到原始错误消息（“无法创建一个接口的实例”）。
如果错误的控制器之前，但之后会发生提交，那么我们可能需要在控制器之前的代码。可能是控制器和视图的签名。 –
好点，刚刚发布在上面的修改中。谢谢！ – NealR
你没有将页面传递给签名。 – DarthVader