.NET 8 Blazor项目：基于.NET Identity的OTP自动登录重定向报错处理

我正在开发一个基于.NET 8 Blazor、采用.NET Identity认证的项目，需求是在OnInitializedAsync方法中，通过查询参数传入的OTP实现用户自动登录并完成重定向。

原实现代码 #

[SupplyParameterFromQuery]
private string Otp { get; set; } = default!;

[Inject]
SignInManager<ApplicationUser> SignInManager { get; set; } = default!;

protected override async Task OnInitializedAsync()
{
    try
    {
        if (HttpMethods.IsGet(HttpContext.Request.Method))
        {
            await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
        }

        if (!string.IsNullOrEmpty(Otp))
        {
            // 验证OTP并获取用户和声明
            await SignInManager.SignInWithClaimsAsync(user, isPersistent: false, claims);
            NavigationManager.NavigateTo("/test");
        }
        else
        {
            NavigationManager.NavigateTo("/error");
        }

        await base.OnInitializedAsync();
    }
    catch (Exception)
    {
        NavigationManager.NavigateTo("/error");
    }
}

遇到的异常 #

执行重定向时抛出以下异常：

Microsoft.AspNetCore.Components.NavigationException: 'Exception of type 'Microsoft.AspNetCore.Components.NavigationException' was thrown.'

可行解决方案 #

问题出在Blazor SSR场景下，NavigationManager.NavigateTo不适合在服务端初始化阶段直接使用。通过扩展HttpContext实现服务端原生重定向，兼容Blazor增强导航：

扩展方法代码 #

public static class BlazorSsrRedirectManagerExtensions
{
    public static void RedirectTo(this HttpContext httpContext, string redirectionUrl)
    {
        ArgumentNullException.ThrowIfNull(httpContext);

        httpContext.Response.Headers.Append("blazor-enhanced-nav-redirect-location", redirectionUrl);
        httpContext.Response.StatusCode = 200;
        httpContext.Response.Redirect(redirectionUrl);
    }
}

修改原逻辑 #

将原代码中的NavigationManager.NavigateTo调用替换为HttpContext.RedirectTo，并在重定向后直接返回，避免后续代码执行：

protected override async Task OnInitializedAsync()
{
    try
    {
        if (HttpMethods.IsGet(HttpContext.Request.Method))
        {
            await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
        }

        if (!string.IsNullOrEmpty(Otp))
        {
            // 验证OTP并获取用户和声明
            await SignInManager.SignInWithClaimsAsync(user, isPersistent: false, claims);
            HttpContext.RedirectTo("/test");
            return; // 重定向后退出方法
        }
        else
        {
            HttpContext.RedirectTo("/error");
            return;
        }

        await base.OnInitializedAsync();
    }
    catch (Exception)
    {
        HttpContext.RedirectTo("/error");
        return;
    }
}

内容的提问来源于stack exchange，提问作者Coder3000