Question

我正在使用ASP.NET Core，并尝试本地化该应用程序。我设法使用 new asp .net核心资源来本地化控制器和视图，并使用旧资源来本地化错误消息以进行模型验证。但是，当错误消息未链接到模型字段注释（例如＆＃34;必需＆＃34;）并且模型绑定的数据不正确时（如预期数字的文本），我收到如下错误，我无法本地化：

＆＃34;价值＆＃39; abc＆＃39;对于ID无效。＆＃34;

当我在abc中为ID属性输入View时，因为无法对该字段进行模型绑定，并且在该字段附近显示验证消息，说 ＆＃34;价值＆＃39; abc＆＃39;对于ID无效。＆＃34; 。以下是我使用的课程：

public class Country : IHasID
{
    public int ID { get; set; }

    [Required(ErrorMessageResourceType = typeof(L.Val),
    ErrorMessageResourceName = "NameR")]
    [MaxLength(100, ErrorMessageResourceType = typeof(L.Val), 
    ErrorMessageResourceName = "Max")]
    public string Name { get; set; }

    /*Some other properties*/
}

我在互联网上发现的类似问题是针对较旧的asp .net版本，否则无法帮助我解决问题。

Answer 1

要自定义框架模型绑定错误消息，您需要为ModelBindingMessageProvider的不同错误消息访问器设置自定义访问者。

实施例

您可以在此处下载本文所述内容的完整源代码。存储库包含 ASP.NET Core 2.0（VS 2017.3）和 ASP.NET Core 1.1（VS 2015）的示例：

r-aghaei/AspNetCoreLocalizationSample

此外，您还可以看到示例：live：

aspnetcorelocalizationsample.azurewebsites.net

默认错误消息

这些是框架在绑定到属性的模型失败时显示的默认错误消息：

MissingBindRequiredValueAccessor    A value for the '{0}' property was not provided.
MissingKeyOrValueAccessor           A value is required.
ValueMustNotBeNullAccessor          The value '{0}' is invalid. 
AttemptedValueIsInvalidAccessor     The value '{0}' is not valid for {1}.
UnknownValueIsInvalidAccessor       The supplied value is invalid for {0}.
ValueIsInvalidAccessor              The value '{0}' is invalid.
ValueMustBeANumberAccessor          The field {0} must be a number.

除上述消息外，ASP.NET Core 2.0还包含以下消息：

MissingRequestBodyRequiredValueAccessor       A non-empty request body is required.
NonPropertyAttemptedValueIsInvalidAccessor    The value '{0}' is not valid.
NonPropertyUnknownValueIsInvalidAccessor      The supplied value is invalid.
NonPropertyValueMustBeANumberAccessor         The field must be a number.

本地化ASP.NET核心模型绑定错误消息

要本地化ASP.NET Core模型绑定错误消息，请按照下列步骤操作：

创建资源文件 - 在解决方案的 Resources 文件夹下创建资源文件，并将文件命名为 ModelBindingMessages.fa.resx 。名称可以是其他任何名称，但我们将使用它来创建本地化程序。在这个例子中，我使用了 fa （波斯语）文化。
添加资源键 - 打开资源文件，添加要用于本地化错误消息的键和值。我使用了键和值，如下图所示：

我使用的密钥与原始邮件类似，但ValueMustNotBeNull的密钥与ValueIsInvalid相同，所以我使用 Null值无效。。

配置选项 - 在ConfigureServices方法中，在添加Mvc时，配置其选项以设置ModelBindingMessageProvider的消息访问者：

public void ConfigureServices(IServiceCollection services)
{
    services.AddLocalization(options => { options.ResourcesPath = "Resources"; });
    services.AddMvc(options =>
    {
        var F = services.BuildServiceProvider().GetService<IStringLocalizerFactory>();
        var L = F.Create("ModelBindingMessages", "AspNetCoreLocalizationSample");
        options.ModelBindingMessageProvider.ValueIsInvalidAccessor =
            (x) => L["The value '{0}' is invalid."];
        options.ModelBindingMessageProvider.ValueMustBeANumberAccessor =
            (x) => L["The field {0} must be a number."];
        options.ModelBindingMessageProvider.MissingBindRequiredValueAccessor =
            (x) => L["A value for the '{0}' property was not provided.", x];
        options.ModelBindingMessageProvider.AttemptedValueIsInvalidAccessor =
            (x, y) => L["The value '{0}' is not valid for {1}.", x, y];
        options.ModelBindingMessageProvider.MissingKeyOrValueAccessor =
            () => L["A value is required."];
        options.ModelBindingMessageProvider.UnknownValueIsInvalidAccessor =
            (x) => L["The supplied value is invalid for {0}.", x];
        options.ModelBindingMessageProvider.ValueMustNotBeNullAccessor =
            (x) => L["Null value is invalid.", x];
    })
    .AddDataAnnotationsLocalization()
    .AddViewLocalization();
    services.Configure<RequestLocalizationOptions>(options =>
    {
        var supportedCultures = new[]{new CultureInfo("en"), new CultureInfo("fa")};
        options.DefaultRequestCulture = new RequestCulture("en", "en");
        options.SupportedCultures = supportedCultures;
        options.SupportedUICultures = supportedCultures;
    });
}

还要在Configure方法的开头添加此代码：

var supportedCultures = new[] { new CultureInfo("en"), new CultureInfo("fa") };
app.UseRequestLocalization(new RequestLocalizationOptions()
{
    DefaultRequestCulture = new RequestCulture(new CultureInfo("en")),
    SupportedCultures = supportedCultures,
    SupportedUICultures = supportedCultures
});

ASP.NET Core 2.0的重要说明

在ASP.NET Core 2.0中，模型绑定消息提供程序属性已获得   只读，但已添加每个属性的setter方法。

例如，要设置   ValueIsInvalidAccessor，您应该使用SetValueIsInvalidAccessor()   方法这样：
options.ModelBindingMessageProvider.SetValueIsInvalidAccessor (
    (x) => L["The value '{0}' is invalid."]);

Answer 2

参考详细描述the side effects for using BuildServiceProvider inside ConfigureServices的帖子以及有关resolving services inside ConfigureServices的答案，最后但并非最不重要的是，考虑到refered improved answer by Andrew Lock，定位模型绑定错误的正确方法消息应该通过创建实现IConfigureOptions<T>的自定义配置类，然后在启动时按如下所示进行注册：

public class ConfigureModelBindingLocalization : IConfigurationOptions<MvcOptions>
{
    private readonly IServiceScopeFactory _serviceFactory;
    public ConfigureModelBindingLocalization(IServiceScopeFactory serviceFactory)
    {
        _serviceFactory = serviceFactory;
    }

    public void Configure(MvcOptions options)
    {
        using(var scope = _serviceFactory.CreateScope())
        {
            var provider = scope.ServiceProvider;
            var localizer = provider.GetRequiredService<IStringLocalizer>();

            options.ModelBindingMessageProvider.SetAttemptedValueIsInvalidAccessor((x, y) => 
                localizer["The value '{0}' is not valid for {1}.", x, y]);

            options.ModelBindingMessageProvider.SetMissingBindRequiredValueAccessor((x) => 
                localizer["A value for the '{0}' parameter or property was not provided.", x]);

            options.ModelBindingMessageProvider.SetMissingKeyOrValueAccessor(() => 
                localizer["A value is required."]);

           options.ModelBindingMessageProvider.SetMissingRequestBodyRequiredValueAccessor(() =>
               localizer["A non-empty request body is required."]);

           options.ModelBindingMessageProvider.SetNonPropertyAttemptedValueIsInvalidAccessor((x) =>
               localizer["The value '{0}' is not valid.", x]);

           options.ModelBindingMessageProvider.SetNonPropertyUnknownValueIsInvalidAccessor(() =>
               localizer["The supplied value is invalid."]);

           options.ModelBindingMessageProvider.SetNonPropertyValueMustBeANumberAccessor(() =>
               localizer["The field must be a number."]);

           options.ModelBindingMessageProvider.SetUnknownValueIsInvalidAccessor((x) =>
               localizer["The supplied value is invalid for {0}.", x]);

           options.ModelBindingMessageProvider.SetValueIsInvalidAccessor((x) =>
               localizer["The value '{0}' is invalid.", x]);

           options.ModelBindingMessageProvider.SetValueMustBeANumberAccessor((x) =>
               localizer["The field {0} must be a number.", x]);

           options.ModelBindingMessageProvider.SetValueMustNotBeNullAccessor((x) =>
               localizer["The value '{0}' is invalid.", x]);
        }
    }
}

最后在启动时注册新的配置类：

public void ConfigureServices(IServiceCollection services)
{
    // ...

    services.AddSingleton<IConfigureOptions<MvcOptions>, ConfigureModelBindingLocalization>();

    // ...
}

Answer 3

在 .NET Core 3.1 和 .NET 5 中测试。创建一个确定 UICulture 的私有方法

private string GetStringValidationError()
    {
        CultureInfo uiCultureInfo = Thread.CurrentThread.CurrentUICulture;

        string errorMessaeg = string.Empty;

        errorMessaeg = uiCultureInfo.ToString() == "ar" ? "هذا الحقل مطلوب" : "This field is required";
        return errorMessaeg;
    }

之后，您可以将此方法附加到 Func 委托作为 SetValueMustNotBeNullAccessor 方法的第一个参数，如下所示：

options.ModelBindingMessageProvider.SetValueMustNotBeNullAccessor(value => GetStringValidationError());

ASP.NET核心模型绑定错误消息本地化

3 个答案:

实施例

默认错误消息

本地化ASP.NET核心模型绑定错误消息