ASP.NET 核心模型绑定错误消息本地化

Question

我正在使用 ASP.NET Core，并尝试对应用程序进行本地化。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 old 资源来本地化模型验证的错误消息. 但是，当错误消息未链接到模型字段注释（如 "Required"）并且模型绑定的数据不正确（如需要数字的文本）时，我收到如下错误，我无法本地化：

"The value 'abc' is not valid for ID."

当我在 View 中为 ID 属性输入 abc 时，由于无法对该字段进行模型绑定，并且它在附近显示验证消息字段，说 "The value 'abc' is not valid for ID."。这是我正在使用的 class：

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*/
}

我在网上找到的类似问题要么是针对旧的asp .net 版本，要么没有帮助我解决问题。

Answer 1

自定义框架模型绑定错误信息，需要为ModelBindingMessageProvider的不同错误信息访问器设置自定义访问器。

例子

在这里您可以下载 post 中描述的完整源代码。该存储库包含 ASP.NET Core 2.0 (VS 2017.3) 和 ASP.NET Core 1.1 (VS 2015) 的示例：

r-aghaei/AspNetCoreLocalizationSample

你也可以在这里看到这个例子，live:

aspnetcorelocalizationsample.azurewebsites.net

默认错误消息

这些是框架在模型绑定到属性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.

除了以上信息，ASP.NETCore 2.0 还有这些信息：

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 核心模型绑定错误消息，请执行以下步骤：

创建资源文件 - 在解决方案的 Resources 文件夹下创建一个资源文件，并将文件命名为 ModelBindingMessages.fa.resx。名称可以是任何其他名称，但我们将使用它来创建本地化程序。在示例中，我使用了 fa（波斯）文化。
添加资源键 - 打开资源文件并添加要用于本地化错误消息的键和值。我使用了如下图所示的键和值：

我使用的密钥与原始消息一样，除了 ValueMustNotBeNull 的密钥与 ValueIsInvalid 相同，所以我使用 Null value is invalid. 为之。

配置选项 - 在ConfigureServices方法中，添加Mvc时，配置其选项以设置[=15的消息访问器=]:

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

同时在 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

In ASP.NET Core 2.0, model binding message provider properties has got read only, but a setter method for each property has been added.

For example, to set ValueIsInvalidAccessor, you should use SetValueIsInvalidAccessor() method this way:
options.ModelBindingMessageProvider.SetValueIsInvalidAccessor (
    (x) => L["The value '{0}' is invalid.", x]);

Answer 2

参考这个 post 详细描述 , and to this answer regarding , last but not least, considering the refered improved answer by Andrew Lock，本地化模型绑定错误消息的正确方法应该是创建一个实现 [=12] 的自定义配置 class =] 然后在启动时注册它如下：

public class ConfigureModelBindingLocalization : IConfigureOptions<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配置class：

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

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

    // ...
}

Answer 3

已在 .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

ASP.NET Core Model Binding Error Messages Localization

.net

c#

localization

asp.net-core

asp.net-core-localization

例子

默认错误消息

本地化 ASP.NET 核心模型绑定错误消息

ASP.NET Core 2.0