获取DisplayName属性的值

Question

public class Class1
{
    [DisplayName("Something To Name")]
    public virtual string Name { get; set; }
}

如何在C#中获取DisplayName属性的值？

Answer 1

尝试我的这些实用方法:

using System.ComponentModel;
using System.Globalization;
using System.Linq;


public static T GetAttribute<T>(this MemberInfo member, bool isRequired)
    where T : Attribute
{
    var attribute = member.GetCustomAttributes(typeof(T), false).SingleOrDefault();

    if (attribute == null && isRequired)
    {
        throw new ArgumentException(
            string.Format(
                CultureInfo.InvariantCulture, 
                "The {0} attribute must be defined on member {1}", 
                typeof(T).Name, 
                member.Name));
    }

    return (T)attribute;
}

public static string GetPropertyDisplayName<T>(Expression<Func<T, object>> propertyExpression)
{
    var memberInfo = GetPropertyInformation(propertyExpression.Body);
    if (memberInfo == null)
    {
        throw new ArgumentException(
            "No property reference expression was found.",
            "propertyExpression");
    }

    var attr = memberInfo.GetAttribute<DisplayNameAttribute>(false);
    if (attr == null)
    {
        return memberInfo.Name;
    }

    return attr.DisplayName;
}

public static MemberInfo GetPropertyInformation(Expression propertyExpression)
{
    Debug.Assert(propertyExpression != null, "propertyExpression != null");
    MemberExpression memberExpr = propertyExpression as MemberExpression;
    if (memberExpr == null)
    {
        UnaryExpression unaryExpr = propertyExpression as UnaryExpression;
        if (unaryExpr != null && unaryExpr.NodeType == ExpressionType.Convert)
        {
            memberExpr = unaryExpr.Operand as MemberExpression;
        }
    }

    if (memberExpr != null && memberExpr.Member.MemberType == MemberTypes.Property)
    {
        return memberExpr.Member;
    }

    return null;
}

用法是:

string displayName = ReflectionExtensions.GetPropertyDisplayName<SomeClass>(i => i.SomeProperty);

Answer 2

您需要获取PropertyInfo与属性相关联(例如,通过typeof(Class1).GetProperty("Name")),然后调用GetCustomAttributes.

由于返回多个值,它有点混乱 - 如果您需要从几个地方需要它,您可能想要编写一个帮助方法来执行此操作.(在某个框架中可能已经有一个帮助方法,但是如果有我不知道的话.)

编辑:由于leppie指出的那样,是这样的方法:Attribute.GetCustomAttribute(MemberInfo, Type)

Answer 3

首先,您需要获取MemberInfo表示该属性的对象.你需要做一些反思:

MemberInfo property = typeof(Class1).GetProperty("Name");

(我正在使用"旧式"反射,但如果您在编译时可以访问该类型,也可以使用表达式树)

然后,您可以获取属性并获取属性的值DisplayName:

var attribute = property.GetCustomAttributes(typeof(DisplayNameAttribute), true)
      .Cast<DisplayNameAttribute>().Single();
string displayName = attribute.DisplayName;

()括号是必需的拼写错误

Answer 4

从具有Class1的视图中,因为它是强类型视图模型:

ModelMetadata.FromLambdaExpression<Class1, string>(x => x.Name, ViewData).DisplayName;

Answer 5

如果有人有兴趣使用DisplayAttribute和ResourceType从属性获取本地化字符串,如下所示:

[Display(Name = "Year", ResourceType = typeof(ArrivalsResource))]
public int Year { get; set; }

之后使用以下内容displayAttribute != null(如上面@alex'答案所示):

ResourceManager resourceManager = new ResourceManager(displayAttribute.ResourceType);
var entry = resourceManager.GetResourceSet(Thread.CurrentThread.CurrentUICulture, true, true)
                           .OfType<DictionaryEntry>()
                           .FirstOrDefault(p => p.Key.ToString() == displayAttribute.Name);

return entry.Value.ToString();

Answer 6

Rich Tebb的精彩课程!我一直在使用DisplayAttribute,代码对我不起作用.我唯一添加的是处理DisplayAttribute.简短的搜索产生了这个属性对于MVC3和.Net 4来说是新的,并且几乎完全相同.这是该方法的修改版本:

 public static string GetPropertyDisplayString<T>(Expression<Func<T, object>> propertyExpression)
    {
        var memberInfo = GetPropertyInformation(propertyExpression.Body);
        if (memberInfo == null)
        {
            throw new ArgumentException(
                "No property reference expression was found.",
                "propertyExpression");
        }

        var displayAttribute = memberInfo.GetAttribute<DisplayAttribute>(false);

        if (displayAttribute != null)
        {
            return displayAttribute.Name;
        }
        else
        {
            var displayNameAttribute = memberInfo.GetAttribute<DisplayNameAttribute>(false);
            if (displayNameAttribute != null)
            {
                return displayNameAttribute.DisplayName;
            }
            else
            {
                return memberInfo.Name;
            }
        }
    }

Answer 7

var propInfo = typeof(Class1).GetProperty("Name");
var displayNameAttribute = propInfo.GetCustomAttributes(typeof(DisplayNameAttribute), false);
var displayName = displayNameAttribute[0] as DisplayNameAttribute).DisplayName;

displayName 变量现在保存属性的值。