使用 Html.BeginCollectionItem 帮助器传递集合的部分视图

Question

我做了一个小项目来了解 Stephen Muecke 的答案：Submit same Partial View called multiple times data to controller?

几乎一切正常。 javascript 从局部视图中添加新字段，我可以通过控制器方法为局部视图插入的“临时”值来判断它们已绑定到模型。

但是，当我提交新字段时，AddRecord() 方法会引发异常，表明模型没有被传入（“对象引用未设置为对象的实例”）。

另外，当我查看页面源代码时，BeginCollectionItem 助手正在插入一个隐藏标记，因为它应该在显示预先存在的记录的主视图中的表周围插入一个隐藏标记，而不是在 javascript 添加的新字段周围。

我做错了什么？我对此很陌生，所以感谢您的耐心等待！

我的主要观点：

@model IEnumerable<DynamicForm.Models.CashRecipient>

@using (Html.BeginForm("AddDetail", "CashRecipients", FormMethod.Post))
{
    @Html.AntiForgeryToken()
    <div id="CSQGroup">
    </div>
}

<div>
    <input type="button" value="Add Field" id="addField" onclick="addFieldss()" />
</div>

<script>
    function addFieldss()
    {   
        //alert("ajax call");
        $.ajax({
            url: '@Url.Content("~/CashRecipients/RecipientForm")',
            type: 'GET',
            success:function(result) {
                //alert("Success");
                var newDiv = document.createElement("div"); 
                var newContent = document.createTextNode("Hi there and greetings!"); 
                newDiv.appendChild(newContent);  
                newDiv.innerHTML = result;
                var currentDiv = document.getElementById("div1");  
                document.getElementById("CSQGroup").appendChild(newDiv);
            },
            error: function(result) {
                alert("Failure");
            }
        });
    }
</script>

我的部分观点：

@model DynamicForm.Models.CashRecipient
@using HtmlHelpers.BeginCollectionItem

@using (Html.BeginCollectionItem("recipients"))
{
    <div class="editor-field">
        @Html.LabelFor(model => model.Id)
        @Html.LabelFor(model => model.cashAmount)
        @Html.TextBoxFor(model => model.cashAmount)
        @Html.LabelFor(model => model.recipientName)
        @Html.TextBoxFor(model => model.recipientName)
    </div>
    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Save" class="btn btn-default" />
        </div>
    </div>
}

我的模特：

public class CashRecipient
{
    public int Id { get; set; }
    public string cashAmount { get; set; }
    public string recipientName { get; set; }  
}

在我的控制器中：

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult AddDetail([Bind(Include = "Id,cashAmount,recpientName")] IEnumerable<CashRecipient> cashRecipient)
{
    if (ModelState.IsValid)
    {
        foreach (CashRecipient p in cashRecipient) {
            db.CashRecipients.Add(p);
        }
        db.SaveChanges();
        return RedirectToAction("Index");

    }

    return View(cashRecipient);
}

public ActionResult RecipientForm()
{
    var data = new CashRecipient();
    data.cashAmount = "temp";
    data.recipientName = "temp";
    return PartialView(data);
}

Answer 1

首先创建一个视图模型来表示您要编辑的内容。我假设cashAmount 是货币值，因此应该是小数（根据需要添加其他验证和显示属性）

public class CashRecipientVM
{
    public int? ID { get; set; }
    public decimal Amount { get; set; }
    [Required(ErrorMessage = "Please enter the name of the recipient")]
    public string Recipient { get; set; }  
}

然后创建一个局部视图（比如）_Recipient.cshtml

@model CashRecipientVM
<div class="recipient">
    @using (Html.BeginCollectionItem("recipients"))
    {
        @Html.HiddenFor(m => m.ID, new { @class="id" })
        @Html.LabelFor(m => m.Recipient)
        @Html.TextBoxFor(m => m.Recipient)
        @Html.ValidationMesssageFor(m => m.Recipient)
        @Html.LabelFor(m => m.Amount)
        @Html.TextBoxFor(m => m.Amount)
        @Html.ValidationMesssageFor(m => m.Amount)
        <button type="button" class="delete">Delete</button>
    }
</div>

以及返回部分的方法

public PartialViewResult Recipient()
{
    return PartialView("_Recipient", new CashRecipientVM());
}

那么你的主要 GET 方法将是

public ActionResult Create()
{
    List<CashRecipientVM> model = new List<CashRecipientVM>();
    .... // add any existing objects that your editing
    return View(model);
}

它的视图将是

@model IEnumerable<CashRecipientVM>
@using (Html.BeginForm())
{
    <div id="recipients">
        foreach(var recipient in Model)
        {
            @Html.Partial("_Recipient", recipient)
        }
    </div>
    <button id="add" type="button">Add</button>
    <input type="submit" value="Save" />
}

并将包含一个脚本来为新的CashRecipientVM 添加 html

var url = '@Url.Action("Recipient")';
var form = $('form');
var recipients = $('#recipients');
$('#add').click(function() {
    $.get(url, function(response) {
        recipients.append(response);
        // Reparse the validator for client side validation
        form.data('validator', null);
        $.validator.unobtrusive.parse(form);
    });
});

以及删除项目的脚本

$('.delete').click(function() {
    var container = $(this).closest('.recipient');
    var id = container.find('.id').val();
    if (id) {
        // make ajax post to delete item
        $.post(yourDeleteUrl, { id: id }, function(result) {
            container.remove();
        }.fail(function (result) {
            // Oops, something went wrong (display error message?)
        }
    } else {
        // It never existed, so just remove the container
        container.remove();
    }
});

表格会发回给

public ActionResult Create(IEnumerable<CashRecipientVM> recipients)