ASP.NET Core 5如何本地化数据注解校验错误响应中自动生成的标题

问题根因 #

One or more validation errors occurred.是ASP.NET Core为校验失败的API响应自动生成的ValidationProblemDetails对象的默认Title字段值，由框架内置的InvalidModelStateResponseFactory硬编码生成，不会走常规DataAnnotation的本地化逻辑，因此直接在SharedResource.resx添加对应键的翻译条目无法生效。

解决步骤 #

1. 保留你已完成的DataAnnotation本地化配置、以及SharedResource.resx中键为One or more validation errors occurred.的翻译条目
2. 在服务注册阶段替换框架默认的无效模型状态响应工厂，手动读取本地化资源替换默认标题

.NET 6及以上版本示例代码 #

using Microsoft.AspNetCore.Localization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Localization;
using System.Globalization;

var builder = WebApplication.CreateBuilder(args);

// 保留你原有本地化服务注册逻辑
builder.Services.AddLocalization(opt => opt.ResourcesPath = "Resources");

builder.Services.AddControllers()
    .AddDataAnnotationsLocalization(opt =>
    {
        // 保留你原有DataAnnotation本地化配置
        opt.DataAnnotationLocalizerProvider = (type, factory) => 
            factory.Create(typeof(SharedResource));
    })
    .ConfigureApiBehaviorOptions(opt =>
    {
        // 替换默认响应工厂
        opt.InvalidModelStateResponseFactory = context =>
        {
            // 获取本地化服务
            var localizer = context.HttpContext.RequestServices
                .GetRequiredService<IStringLocalizer<SharedResource>>();
            
            var validationProblem = new ValidationProblemDetails(context.ModelState)
            {
                // 替换为本地化后的标题
                Title = localizer["One or more validation errors occurred."],
                Status = StatusCodes.Status400BadRequest
            };

            return new BadRequestObjectResult(validationProblem)
            {
                ContentTypes = { "application/problem+json", "application/problem+xml" }
            };
        };
    });

// 保留你原有请求本地化中间件配置
var app = builder.Build();
var supportedCultures = new[] { new CultureInfo("de"), new CultureInfo("en"), new CultureInfo("zh-CN") };
app.UseRequestLocalization(new RequestLocalizationOptions
{
    DefaultRequestCulture = new RequestCulture("de"),
    SupportedCultures = supportedCultures,
    SupportedUICultures = supportedCultures
});

app.MapControllers();
app.Run();

.NET 5及更早版本示例代码（Startup.cs） #

在ConfigureServices方法中添加如下配置：

public void ConfigureServices(IServiceCollection services)
{
    // 保留你原有本地化、控制器服务注册逻辑
    services.AddLocalization(opt => opt.ResourcesPath = "Resources");
    services.AddControllers()
        .AddDataAnnotationsLocalization(opt =>
        {
            opt.DataAnnotationLocalizerProvider = (type, factory) => 
                factory.Create(typeof(SharedResource));
        })
        .ConfigureApiBehaviorOptions(opt =>
        {
            opt.InvalidModelStateResponseFactory = context =>
            {
                var localizer = context.HttpContext.RequestServices
                    .GetRequiredService<IStringLocalizer<SharedResource>>();
                
                var validationProblem = new ValidationProblemDetails(context.ModelState)
                {
                    Title = localizer["One or more validation errors occurred."],
                    Status = StatusCodes.Status400BadRequest
                };

                return new BadRequestObjectResult(validationProblem)
                {
                    ContentTypes = { "application/problem+json", "application/problem+xml" }
                };
            };
        });
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // 保留你原有请求本地化中间件配置
    var supportedCultures = new[] { new CultureInfo("de"), new CultureInfo("en"), new CultureInfo("zh-CN") };
    app.UseRequestLocalization(new RequestLocalizationOptions
    {
        DefaultRequestCulture = new RequestCulture("de"),
        SupportedCultures = supportedCultures,
        SupportedUICultures = supportedCultures
    });

    // 其他中间件配置...
    app.UseRouting();
    app.UseEndpoints(endpoints => endpoints.MapControllers());
}

内容的提问来源于stack exchange，提问作者MJBZA