c# - ReturnUrl 在使用 ASP.NET Core 6 MVC 的 POST 上始终为 null

Question

我无法使用 ASP.NET Core 6 MVC 让 ReturnUrl 在 HttpPost 上工作。

在POST 方法中添加断点时，returnurl 始终为null。但是对于 .NET 5，除了 .NET 6 之外，它使用相同的代码设置，我需要使 returnurl 参数可为空，这样我就不会收到错误“returnurl field is required” .

这是我正在使用的代码 - 任何帮助将不胜感激。

谢谢。

型号:

namespace IdentityManagerDotNet6.Models
{
    public class LoginViewModel
    {
        [Required]
        [EmailAddress]
        public string Email { get; set; } = string.Empty;

        [Required]
        [DataType(DataType.Password)]
        public string Password { get; set; } = string.Empty;

        [Display(Name = "Remember me?")]
        public bool RememberMe { get; set; }
    }
}

Controller

[HttpGet]
public IActionResult Login(string? returnurl)
{
    ViewData["ReturnUrl"] = returnurl;
    return View();
}

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Login(LoginViewModel loginViewModel, string? returnurl)
{
    ViewData["ReturnUrl"] = returnurl;
    returnurl = returnurl ?? Url.Content("~/");

    if (ModelState.IsValid)
    {
        var result = await _signInManager.PasswordSignInAsync(loginViewModel.Email, loginViewModel.Password, loginViewModel.RememberMe, lockoutOnFailure: true);

        if (result.Succeeded)
        {
            return LocalRedirect(returnurl);
        }

        if (result.IsLockedOut)
        {
            return View("Lockout");
        }
        else
        {
            ModelState.AddModelError(string.Empty, "Invalid login attempt.");
            return View(loginViewModel);
        }
    }

    return View(loginViewModel);
}

查看:

@model LoginViewModel

<h1 class="text-info">Log in</h1>
<div class="row">
    <div class="col-md-8">
        <form asp-controller="Account" asp-action="Login" asp-route-returnurl="@ViewData["ReturnUrl"]" method="post" role="form">
            <h4>Use a local account to log in</h4>
            <hr />
            <div asp-validation-summary="All" class="text-danger"></div>
            <div class="form-group">
                <label asp-for="Email" class="col-md-2"></label>
                <div class="col-md-10">
                    <input asp-for="Email" class="form-control" />
                    <span asp-validation-for="Email" class="text-danger"></span>
                </div>
            </div>
            <div class="form-group mt-3">
                <label asp-for="Password" class="col-md-2"></label>
                <div class="col-md-10">
                    <input asp-for="Password" class="form-control" />
                    <span asp-validation-for="Password" class="text-danger"></span>
                </div>
            </div>
            <div class="form-check mt-3">
                <input class="form-check-input" asp-for="RememberMe" type="checkbox" value="" id="flexCheckChecked">
                <label class="form-check-label" asp-for="RememberMe" for="flexCheckChecked">
                    Remember me?
                </label>
            </div>
            <div class="form-group">
                <div class=" col-1 my-3">
                    <button type="submit" asp-controller="Account" asp-action="Login" class="btn btn-success form-control">Login</button>
                </div>
            </div>
            <p>
                <a asp-action="Register">Register as a new user?</a>
            </p>
            <p>
                <a asp-action="ForgotPassword">Forgot your passord?</a>
            </p>
        </form>
    </div>
</div>

Answer 1

“我无法使用 ASP.NET Core 6 MVC 让 ReturnUrl 在 HttpPost 上工作。”:

I have checked your code between the line. It doesn't has anythingwrong with [FromQuery] So you don't need to do anything on [FromQuery] as other answer I've seen, may be deleted now.

问题复制:

我已成功重现您的问题，如下所示:

导致问题的原因:

If you investigate your code again you would noticed that you areusing asp-controller="Login" asp-action="Login" twice on yourLogin.cshtml at the begining of the form and at the point of submit button this causing the data loss while you are submitting the form.

在表单的开头:

   <form asp-controller="Login" asp-action="Login" asp-route-returnurl="@ViewData["ReturnUrl"]" method="post" role="form">

在您的按钮上提交::

 <button type="submit" asp-controller="Login" asp-action="Login" class="btn btn-success form-control">Login</button>

解决方案:

最简单的解决方案就是像下面这样修改您的提交按钮代码，这将解决您的问题:

            <div class="form-group">
                <div class=" col-1 my-3">
                    <button type="submit" class="btn btn-success form-control">Login</button>
                </div>
            </div>

输出:

希望它能彻底解决您的returnurl null 问题。