调用 POST 方法时 ASP.NET MVC Model 属性为 null

Question

在 Controller 操作中，我进行了以下调用，其中 userId 是已知的非空值:

return View("ChangePassword", new ChangePasswordBindingModel(userId));

以下是 ChangePasswordBindingModel 的定义:

public class ChangePasswordBindingModel
{
    private string currentUserId;
    [Required]
    [DataType(DataType.Password)]
    //[Display(Name = "Current password")]
    public string OldPassword { get; set; }

    [Required]
    //[StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]
    [DataType(DataType.Password)]
    [Display(Name = "New password")]
    public string NewPassword { get; set; }

    [Required]
    [DataType(DataType.Password)]
    //[Display(Name = "Confirm new password")]
    [Compare("NewPassword", ErrorMessage = "The new password and confirmation password do not match.")]
    public string ConfirmPassword { get; set; }

    public ChangePasswordBindingModel()
    {

    }
    public ChangePasswordBindingModel(string userId)
    {
        this.currentUserId = userId;
    }

    public string GetUserId()
    {
        return this.currentUserId;
    }
}

以下是绑定(bind)到 ChangePassword 模型的 View :

@model IdentityDevelopment.Models.ChangePasswordBindingModel
@{ ViewBag.Title = "ChangePassword";
}

@Html.ValidationSummary(false)
<h2>Change Password</h2>


@using (Html.BeginForm("ChangePassword","Account", FormMethod.Post))
{
   @Html.AntiForgeryToken();
    <input type="hidden" name="returnUrl" value="@ViewBag.returnUrl" />

    <div class="form-group">
        <label>Current Password</label>
        @Html.PasswordFor(x => x.OldPassword, new { @class = "form-control" })
    </div>

    <div class="form-group">
        <label>New Password</label>
        @Html.PasswordFor(x => x.NewPassword, new { @class = "form-control" })
    </div>


    <div class="form-group">
        <label>Re-enter New Password</label>
        @Html.PasswordFor(x => x.ConfirmPassword, new { @class = "form-control" })
    </div>

    <!-- <button class="btn btn-primary" type="submit">Save</button> -->
    <input class="btn btn-primary" type="submit" value="Save" />
}

最后，这是用于在上述表单上单击Save 的 Post 方法:

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> ChangePassword(ChangePasswordBindingModel loginChange)
{
    if (ModelState.IsValid)
    {
        IdentityResult result = null;
        try
        {
            string userid = loginChange.GetUserId();
            result = await UserManager.ChangePasswordAsync(userid, loginChange.OldPassword, loginChange.NewPassword);

        }
        catch (Exception ex)
        {

        }
        if (result != null && result.Succeeded)
        {
            return RedirectToAction("Index");
        }
        else
        {
            if(result != null)
            {
                AddErrorsFromResult(result);
            }

        }
    }

    return View(loginChange);
}

问题是 userid 没有设置为非空值，正如我认为 GetUserId() 会做的那样。为什么发送到 post 方法的 Model 的 currentUserId 属性不包含该值？我通过在调试期间单步调用 GetUserId() 来确认这一点。

Answer 1

首先将 currentUserId 公开，然后将其放入 View 中的隐藏字段中。

 @Html.HiddenFor(x => x.currentUserId )