如何在 C# 中本地化属性描述？

Question

我正在编写一门课程，该课程将被其他国家的一些人使用。我必须本地化每条消息，警告 e.c.以便他们能够理解我们的意思。在许多情况下，我实现了我的目标。但是这些像描述这样的属性属性实在是太让人头疼了。

这是我现在拥有的：

[Category("Editable Values"), Description("Sets the minimum select...")]
    public Ampere Simin
    {
        get
        {...}
        set
        {...}
    }

和

[Category("Editable Values"), Description(Localisation.Simin)] // "Localisation" here is the internal resource file that i wrote for messages, warnings, exceptions and -unfortunately- descriptions
        public Ampere Simin
        {
            get
            {...}
            set
            {...}
        }

这就是我想要做的。但是以这种方式使用本地化是不可能的。对我可以使用的东西有什么建议吗？

Answer 1

子类：

[STAThread]
static void Main()
{   // just some example code to show it working in winforms, but
    // anything using System.ComponentModel should see the change
    Application.EnableVisualStyles();        
    Application.Run(new Form {Controls = {new PropertyGrid {Dock = DockStyle.Fill, SelectedObject = new Foo()}}});
}

class Foo
{   // assume the following literals are keys, for example to a RESX
    [LocalizedCategory("cat")]
    [LocalizedDescription("desc")]
    [LocalizedDisplayName("disp name")]
    public string Bar { get; set; }
}
[AttributeUsage(AttributeTargets.Assembly | AttributeTargets.Module | AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum | AttributeTargets.Constructor | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Interface | AttributeTargets.Parameter | AttributeTargets.Delegate | AttributeTargets.ReturnValue | AttributeTargets.GenericParameter)]
class LocalizedDescriptionAttribute : DescriptionAttribute
{
    static string Localize(string key)
    {
        // TODO: lookup from resx, perhaps with cache etc
        return "Something for " + key;
    }
    public LocalizedDescriptionAttribute(string key)
        : base(Localize(key))
    {
    }
}
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Event)]
class LocalizedDisplayNameAttribute : DisplayNameAttribute
{
    static string Localize(string key)
    {
        // TODO: lookup from resx, perhaps with cache etc
        return "Something for " + key;
    }
    public LocalizedDisplayNameAttribute(string key)
        : base(Localize(key))
    {
    }
}
[AttributeUsage(AttributeTargets.Assembly | AttributeTargets.Module | AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum | AttributeTargets.Constructor | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Interface | AttributeTargets.Parameter | AttributeTargets.Delegate | AttributeTargets.ReturnValue | AttributeTargets.GenericParameter)]
class LocalizedCategoryAttribute : CategoryAttribute
{
    public LocalizedCategoryAttribute(string key) : base(key) { }
    protected override string  GetLocalizedString(string value)
    {
            // TODO: lookup from resx, perhaps with cache etc
        return "Something for " + value;
    }
}

Answer 2

我结合了Marc Gravell 和dsmith 的答案：

首先：创建一个名为 LocalizedDescriptionAttribute 的 Attribute 类

public class LocalizedDescriptionAttribute : DescriptionAttribute
{
    static string Localize(string key)
    {
        return YourResourceClassName.ResourceManager.GetString(key);
    }

    public LocalizedDescriptionAttribute(string key)
        : base(Localize(key))
    {
    }
}

将其用作LocalizedDescription（“属性”一词不是必需的）

public class Foo
{   
    // myString is a key that exists in your Resources file
    [LocalizedDescription("myString")]
    public string Bar { get; set; }
}

Answer 3

[Required(ErrorMessageResourceName = "LogOnModel_UserName_Required",     
      ErrorMessageResourceType = typeof(Resources.Global))]    
[Display(Name = "LogOnModel_UserName_Required",resourceType = typeof(Resources.Global))]  
public string UserName { get; set; }

见：http://geekswithblogs.net/shaunxu/archive/2010/05/06/localization-in-asp.net-mvc-ndash-3-days-investigation-1-day.aspx

Answer 4

让我们以这个示例类为例：

// ------------------------------------------------------------------------
public class Customer
{
    // ----------------------------------------------------------------------
    [Category( "Editable Values" ), LocDescription( "FirstName", "Sets the first name..." )]
    public string FirstName { get; set; }

    // ----------------------------------------------------------------------
    [Category( "Editable Values" ), LocDescription(  Key = "LastName", DefaultDescription = "Sets the last name..." )]
    public string LastName { get; set; }
} // class Customer

现在可以实现自定义属性类了：

// ------------------------------------------------------------------------
public class LocDescriptionAttribute : DescriptionAttribute
{
    // ----------------------------------------------------------------------
    public LocDescriptionAttribute()
    {
    } // LocDescriptionAttribute

    // ----------------------------------------------------------------------
    public LocDescriptionAttribute( string key, string defaultDescription ) :
        base( defaultDescription )
    {
        Key = key;
        DefaultDescription = defaultDescription;
    } // LocDescriptionAttribute

    // ----------------------------------------------------------------------
    public string Key { get; set; }

    // ----------------------------------------------------------------------
    public string DefaultDescription { get; set; }

    // ----------------------------------------------------------------------
    public override string Description
    {
        get
        {
            // load from resx
            string description = Strings.GetString( Key );
            if ( string.IsNullOrEmpty( description ) )
            {
                description = DefaultDescription;
            }
            return description;
        }
    } // Description
} // class LocDescriptionAttribute

现在您有了本地化描述：

AttributeCollection attributes = TypeDescriptor.GetProperties( customer )[ "FirstName" ].Attributes;
DescriptionAttribute myAttribute = (DescriptionAttribute)attributes[ typeof( DescriptionAttribute ) ];
ConsoleWiterLine( myAttribute.Description );

Answer 5

对 Jani 的回答稍作扩展（对我来说效果很好）：

string description = Strings.GetString( Key );

可以更清楚地做到

ResourceManager rm = YourResourceClassName.ResourceManager;
string description = rm.GetString(Key);

含糊其辞，但不清楚原始代码中缺少什么。资源类的.ResourceManager 属性是自动生成的。

然后，要访问它，请使用 Glennular 在此处描述的扩展方法：StackOverflow 而不是在字段/类名称中进行硬编码（只需使用 LocDescriptionAttribute 而不是 DescriptionAttribute）。

我所做的唯一其他调整是基于this IComparable enum 使其成为静态，以允许它被任何枚举使用，而不是被锁定为特定类型；这是我能做的最好的事情，因为我无法应用接口将其限制为我添加了描述的枚举。

Answer 6

CategoryAttribute 似乎有根据内部资源查找本地化字符串的代码，但DescriptionAttribute 没有本地化。

来自反射器：

public string Category
{
    get
    {
        if (!this.localized)
        {
            this.localized = true;
            string localizedString = this.GetLocalizedString(this.categoryValue);
            if (localizedString != null)
            {
                this.categoryValue = localizedString;
            }
        }
        return this.categoryValue;
     }
}

我认为您会扩展属性并创建自己的实现，传入 ResourceType。像这样的东西，模糊地基于DataAnnotation 逻辑。显然需要更多的清理。

public class LocaleDescriptionAttribute : DescriptionAttribute
{
    ...

    public LocaleDescriptionAttribute(string resourceKey, Type resourceType)
        : base(resourceKey)
    {
        this.resourceType = resourceType;
    }

    public override string  Description
    {
        get 
        { 
            var description = base.Description;
            PropertyInfo property = resourceType.GetProperty(
                       description, BindingFlags.Public | BindingFlags.Static);
            if (property == null)
            {
                return description;
            }
            return property.GetValue(null, null) as string;
        }
    }    
}