带有 IEnumerable 字段的 ASP.NET Core MVC 后模型答案

【问题标题】：ASP.NET Core MVC post model with IEnumerable field带有 IEnumerable 字段的 ASP.NET Core MVC 后模型
【发布时间】：2020-10-06 07:20:50
【问题描述】：

我正在尝试发布带有几个隐藏字段的模型（基本上是保存用户输入）。

此视图的模型：

public class LoanModel
{
    public LoanCalendarDTO LoanCalendar { get; set; }
    public EnterLoanParams LoanParams { get; set; }
}

我尝试发回的模型：

public class EnterLoanParams
{
    [Required]
    [DataType(DataType.Currency)]
    public double TotalLoanAmount { get; set; }

    [Required]
    [RegularExpression(@"([0-9]{0,2}(,{0,1}([0-9]{0,2})))", ErrorMessage = "Please enter in format as xx,xx")]
    public string Rate { get; set; }

    [Required]
    [RegularExpression(@"([0-9]{0,2})", ErrorMessage = "2 digits ")]
    public int YearsToPay { get; set; }

    [Required] [DataType(DataType.Date)] public DateTime Start { get; set; }
    public List<DecreaseModel> Decreases { get; set; } = new List<DecreaseModel>();
}

而DecreaseModel 是：

public class DecreaseModel
{
    [Required] 
    public string DecreaseType { get; set; }

    [Required] 
    public double Amount { get; set; }

    [Required] 
    public DateTime? Start { get; set; }

    public DateTime? End { get; set; }
    public Guid ID { get; set; }

    public DecreaseModel()
    {
        ID = Guid.NewGuid();
    }
}

在视图中我将它们显示为：

@model Front.Models.LoanModel

@{
    ViewBag.Title = "title";
    Layout = "_Layout";
}
<form method="post" asp-controller="Home" id="form">
    <input class="form-control" name="TotalLoanAmount" type="number" asp-for="LoanParams.TotalLoanAmount" hidden/>
    <input class="form-control" name="Rate" type="text" asp-for="LoanParams.Rate" hidden/>
    <input class="form-control"  name="YearsToPay" type="text" asp-for="LoanParams.YearsToPay" hidden/>
    <input class="form-control" name="Start" type="date" asp-for="LoanParams.Start" hidden/>

    @for (int index = 0; index < Model.LoanParams.Decreases.Count; index++)
          {
              @Html.HiddenFor(m => @Model.LoanParams.Decreases[index].Amount)
              @Html.HiddenFor(m => @Model.LoanParams.Decreases[index].Start)
              @Html.HiddenFor(m => @Model.LoanParams.Decreases[index].End)
              @Html.HiddenFor(m => @Model.LoanParams.Decreases[index].DecreaseType)
              @Html.HiddenFor(m => @Model.LoanParams.Decreases[index].ID)
          }

    <button class="btn col-12 btn-success align-content-center btn-lg"
            asp-action="Index" asp-controller="Home" type="submit">Return Back</button>
</form>

我可以看到隐藏字段在浏览器调试器中填充了正确的值：

发布操作：

[HttpPost]
public IActionResult Index(EnterLoanParams loan)
{
    return View(loan);
}

但在帖子中我收到空列表：

Assign IENumerable<int> to a hiddenfor

编辑：视图的工作代码：

 @for (int index = 0; index < Model.LoanParams.Decreases.Count; index++)
          {
              <input class="form-control" name="Decreases[@index].Amount" type="number"
                     asp-for="LoanParams.Decreases[index].Amount" hidden/>
              <input class="form-control" name="Decreases[@index].DecreaseType" type="text" 
                     asp-for="LoanParams.Decreases[index].DecreaseType" hidden/>
              <input class="form-control" name="Decreases[@index].Start" type="date" 
                     asp-for="LoanParams.Decreases[index].Start" hidden/>
              <input class="form-control" name="Decreases[@index].End" type="date" 
                     asp-for="LoanParams.Decreases[index].End" hidden/>
              <input class="form-control" name="Decreases[@index].ID" 
                     asp-for="LoanParams.Decreases[index].ID" hidden/>           
          }

【问题讨论】：

标签： class post asp.net-core-mvc ienumerable

【解决方案1】：

Decreases 的隐藏字段的name 属性具有LoanParams. 前缀，这意味着它们将寻找绑定到名称为LoanParams 的模型。

您需要创建name Decreases[index].{Prop}（就像您对其他隐藏字段所做的那样）。你可以像<input type='hidden' name='Decreases[index].{Prop}' value='your-value'>那样做

【讨论】：