Question

我有三个asp mvc模型

单元 [DatabaseGeneratedAttribute（DatabaseGeneratedOption.Identity）] public int UnitId {get;组; } [需要] [StringLength（25）] public string UnitName {get;组; } 的银行

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int BankId { get; set; }
    [Required]
    [StringLength(25)]
   public string BankName { get; set; }

的BankAccount

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int BankAccountId { get; set; }
    [Required]
    public int BankId { get; set; }
    [Required]
    public int UnitId { get; set; }
    [Required]
    [StringLength(25)]
    public string BankAccountNumber { get; set; }
    public virtual Bank Bank { get; set; }
    public virtual Unit Unit { get; set; }

BankAccountsController

// GET: BankAccounts/Create
    public IActionResult Create()
    {
        ViewData["BankId"] = new SelectList(_context.Bank, "BankId", "Bank");
        ViewData["UnitId"] = new SelectList(_context.Unit, "UnitId", "Unit");
        return View();
    }

**在创建视图VS 2015脚手架代码**

    <div class="form-group">
        <label asp-for="UnitId" class="col-md-2 control-label"></label>
        <div class="col-md-10">
            <select asp-for="UnitId" class="form-control"></select>
        </div>
    </div>
    <div class="form-group">
        <label asp-for="BankId" class="col-md-2 control-label"></label>
        <div class="col-md-10">
            <select asp-for="BankId" class ="form-control"></select>
        </div>
    </div>

下拉列表为空如何解决？

Answer 1

我认为问题在于缺少ViewData和选择列表之间的关联。

可以看到here，我认为您需要使用asp-items将ViewData与select列表绑定。

<select asp-for="UnitId" class="form-control" asp-items="HereGoesViewDataOrViewBagForUnits"></select>

Answer 2

控制器新代码

//ViewData["BankId"] = new SelectList(_context.Bank, "BankId", "Bank");
//ViewData["UnitId"] = new SelectList(_context.Unit, "UnitId", "Unit");
ViewData["BankId"] = new SelectList(_context.Set<Bank>(), "BankId", "BankName");
ViewData["UnitId"] = new SelectList(_context.Set<Unit>(), "UnitId", "UnitName");

新视图代码

<select class="form-control"
                    asp-for="UnitId"
                    asp-items="ViewBag.UnitId"></select>
<select class ="form-control" 
                    asp-for="BankId" 
                    asp-items="ViewBag.BankId"></select>

ASP Core MVC Scaffolding SelectList（RC1）不填充数据

2 个答案: