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我们已经编写了一个自定义TagHelper来以通用方式处理自动完成。它有一个 asp-for 属性，定义为 ModelExpression 变量。

自动完成TagHelper写出一个隐藏字段（Id 字段），以及一个供自动完成 js 代码工作的输入字段。它最终将所选项目的 Id 值保存到隐藏字段。此自动完成功能非常适用于表单上的多个字段。

但是当自动完成功能TagHelper被合并到一个项目列表中时，使用 anEditorTemplate来显示所有项目相同（EditorFor在模型中的 List 上使用），那么我们需要在隐藏字段上设置基于 Z 索引的名称，以便它返回到控制器作为项目列表。例如z0__*Field*, Z1__*Field*, ...

  • 我们如何获得需要添加到所有字段名称前面的基于 Z 索引的名称前缀？
  • 我们必须自己弥补吗？
  • 还是我们从ModelExpression某种方式中提取？
  • 标准输入TagHelper是否得到正确处理？
  • EditorFor/是EditorTemplate处理 ASP.NET Core 1 中可编辑对象列表的正确方法吗？

自动完成 TagHelper

public class AutocompleteTagHelper : TagHelper
{
    public ModelExpression AspFor { get; set; }

    public ModelExpression AspValue { get; set; }

    //public string AspFor { get; set; }

    public string Route { get; set; }
    public string RouteParameters { get; set; }
    public string TargetWrapper { get; set; }
    public string DisplayFormat { get; set; }
    public string ValueFormat { get; set; }

    public string ManageListCallback { get; set; }
    public string ListWrapper { get; set; }

    public string Placeholder { get; set; }

    private SkillDbContext _context;
    private readonly UserManager<ApplicationUser> _userManager;
    private IMemoryCache cache;
    public AutocompleteTagHelper(SkillDbContext Context, UserManager<ApplicationUser> userManager, IMemoryCache cache)
    {
        _context = Context;
        _userManager = userManager;
        this.cache = cache;
    }

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        var hiddenVal = "";
        var displayVal = "";
        //asp-for="LandingPointId" 
        //route="/Lookups/GetLandingPoint" 
        //route-parameter="SomeOtherId" 
        //target-wrapper="form" key="Id" 
        //label="{Name} ({Code})" 
        //output="{code}"
        //AspFor.

        //get parent model from AspFor

        object thisModel = null;

        //get value properties
        if (AspValue != null)
        {
            hiddenVal = ValueFormat;
            displayVal = DisplayFormat;

            thisModel = AspValue.Model;

        }
        else if (AspFor.Model != null && !AspFor.Model.Equals((object)0))
        {
            Object Id = AspFor.Model;
            string routeMethod = Route.Split('/').Last<string>();
        }

        if(thisModel != null)
        {
            PropertyInfo[] propertyInfo = thisModel.GetType().GetProperties();
            foreach (var info in propertyInfo)
            {
                var val = info.GetValue(thisModel);
                if (val != null)
                {
                    hiddenVal = hiddenVal.Replace(("{" + info.Name + "}"), val.ToString());
                    displayVal = displayVal.Replace(("{" + info.Name + "}"), val.ToString());
                }

            }
        }
        var isAcList = ManageListCallback != null && ListWrapper != null;

        string aspForName = AspFor.Name.Replace(".", "_");
        output.TagName = "input";    // replaces <email> with <a> tag
        inputId = inputName = aspForName;
        output.Attributes["id"] = aspForName;
        output.Attributes["name"] = aspForName;
        output.Attributes["type"] = "text";

        output.Attributes["route"] = Route;
        output.Attributes["route-parameters"] = RouteParameters;
        output.Attributes["target-wrapper"] = TargetWrapper;

        output.Attributes["placeholder"] = Placeholder;

        output.Attributes["value-format"] = ValueFormat;
        output.Attributes["display-format"] = DisplayFormat;
        output.Attributes["value"] = displayVal;

        output.Attributes["class"] = "autocomplete form-control" + (isAcList?" hasList":"");

        TagBuilder HiddenValue = new TagBuilder("input");
        HiddenValue.Attributes["name"] = inputName;
        HiddenValue.Attributes["id"] = inputId + "_hidden";
        HiddenValue.Attributes["type"] = "hidden";
        HiddenValue.Attributes["value"] = hiddenVal;

        output.PreElement.SetContent(HiddenValue);

        if (isAcList)
        {
            TagBuilder AddBtn = new TagBuilder("a");

            AddBtn.Attributes["id"] = AspFor.Name.Replace(".", "_") + "_submit";
            AddBtn.Attributes["class"] = "moana-autocomplete-list-manager disabled btn btn-primary";
            AddBtn.Attributes["listwrapper"] = ListWrapper;
            AddBtn.Attributes["href"] = ManageListCallback;

            AddBtn.InnerHtml.AppendHtml("Add");
            output.PostElement.SetContent(AddBtn);
        }

    }

这是模型

public class AddressEditorModel 
{

    public  int Id { get; set; }

    public string AddressLinkTo { get; set; }

    public int AddressLink { get; set; }

    public string AddressLine { get; set; }

    public int ContactTypeId { get; set; }

    public string Suburb { get; set; }

    public string City { get; set; }

    public string Postcode { get; set; }

    public int? CountryId { get; set; }

    public string ContactTypeName { get; set; }

    public string CountryCode { get; set; }
    public string CountryName { get; set; }
}

这是cshtml

@model List<Skill.ViewModels.AddressEditorModel>

<div class="address-info-wrapper">
    @Html.EditorFor(m => m)
<div>

这是控制器方法调用 

public async Task<IActionResult> UpdateAddressInfo(List<AddressEditorModel> addresses)

最后这是 EditorTemplate

@model Skill.ViewModels.AddressEditorModel

<input type="hidden" asp-for="Id" />
<input type="hidden" asp-for="ContactTypeId" />
<input type="hidden" asp-for="AddressLink" />
<input type="hidden" asp-for="AddressLinkTo" />
<input type="hidden" asp-for="CountryId" />

<label class="col-md-12 control-label" style="padding-bottom:20px;">@Model.ContactTypeName</label>
<div class="form-group">
    <label asp-for="AddressLine" class="col-md-2 control-label">Address</label>
    <div class="col-md-10">
        <input asp-for="AddressLine" class="form-control" style="resize:both" />
        <span asp-validation-for="AddressLine" class="text-danger" />
    </div>
</div>
<div class="form-group">
    <label asp-for="Suburb" class="col-md-2 control-label">Suburb</label>
    <div class="col-md-10">
        <input asp-for="Suburb" class="form-control" />
        <span asp-validation-for="Suburb" class="text-danger" />
    </div>
</div>
<div class="form-group">
    <label asp-for="City" class="col-md-2 control-label">City</label>
    <div class="col-md-10">
        <input asp-for="City" class="form-control" />
        <span asp-validation-for="City" class="text-danger" />
    </div>
</div>
<div class="form-group">
    <label class="col-md-2 control-label">Country</label>
    <div class="col-md-10">
        <autocomplete asp-for="CountryId" route="/Lookups/GetCountry" target-wrapper="form" display-format="{Name} ({Code})" value-format="{Id}"></autocomplete>
        <span asp-validation-for="CountryId" class="text-danger" />
    </div>
</div>
<div class="form-group">
    <label asp-for="Postcode" class="col-md-2 control-label">Post Code</label>
    <div class="col-md-10">
        <input asp-for="Postcode" class="form-control" />
        <span asp-validation-for="Postcode" class="text-danger" />
    </div>
</div>

请注意， EditorTemplate 中的上述自动完成标签会生成自己的内部标签（作为标签助手的一部分）。

这是第一个地址信息页面的一部分（如firefox中所示）

<input id="z0__Id" type="hidden" value="5" name="[0].Id" data-val-required="The Id field is required." data-val="true">
<input id="z0__ContactTypeId" type="hidden" value="1" name="[0].ContactTypeId" data-val-required="The ContactTypeId field is required." data-val="true">
<input id="z0__AddressLink" type="hidden" value="1" name="[0].AddressLink" data-val-required="The AddressLink field is required." data-val="true">
<input id="z0__AddressLinkTo" type="hidden" value="F" name="[0].AddressLinkTo">
<label class="col-md-12 control-label" style="padding-bottom:20px;">Work</label>
<div class="form-group">
<label class="col-md-2 control-label" for="z0__AddressLine">Address</label>
<div class="col-md-10">
<input id="z0__AddressLine" class="form-control" type="text" value="4a Lansdowne Street" name="[0].AddressLine" style="resize:both">
<span class="text-danger field-validation-valid" data-valmsg-replace="true" data-valmsg-for="[0].AddressLine"> </span>
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="z0__Suburb">Suburb</label>
<div class="col-md-10">
<input id="z0__Suburb" class="form-control" type="text" value="Bayswater" name="[0].Suburb">
<span class="text-danger field-validation-valid" data-valmsg-replace="true" data-valmsg-for="[0].Suburb"> </span>
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="z0__City">City</label>
<div class="col-md-10">
<input id="z0__City" class="form-control" type="text" value="Auckland" name="[0].City">
<span class="text-danger field-validation-valid" data-valmsg-replace="true" data-valmsg-for="[0].City"> </span>
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label">Country</label>
<div class="col-md-10">
<input id="CountryId_hidden" type="hidden" value="1" name="CountryId">
<input id="CountryId" class="moana-autocomplete form-control ui-autocomplete-input" type="text" value="New Zealand (NZ)" display-format="{Name} ({Code})" value-format="{Id}" placeholder="" target-wrapper="form" route-parameters="" route="/Lookups/GetCountry" name="CountryId" autocomplete="off">
<span class="text-danger field-validation-valid" data-valmsg-replace="true" data-valmsg-for="[0].CountryId"> </span>
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="z0__Postcode">Post Code</label>
<div class="col-md-10">
<input id="z0__Postcode" class="form-control" type="text" value="0604" name="[0].Postcode">
<span class="text-danger field-validation-valid" data-valmsg-replace="true" data-valmsg-for="[0].Postcode"> </span>
</div>
</div>

请注意，Html.EditorFor 生成输入名称属性的 Z n __字段名前缀以及 [ n ]。输入 id 属性的fieldname名称

问题是如何访问索引值，或获取此前缀以附加到从 TagHelper 内部生成的输入，即 Z n __* 或 [ n ] 值，它本质上是 EditorFor 的索引器，因为它生成重复的字段

谢谢你的帮助

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1 回答 1

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好的，我一直在努力工作。我最终不得不查看来自 Asp.Net 核心源项目的 TagHelpers。

我发现我们需要访问 ViewContext.ViewData.TemplateInfo; 从 TagHelper 内部。

或者，我们可以使用 IHtmlGenerator 对象 - 调用 GenerateTextBox、GenerateHidden 等来根据需要构建 TageHelpers

于 2016-03-04T07:25:11.013 回答