要获取一个属性在字典中的所有属性，请使用以下命令:

typeof(Book)
  .GetProperty("Name")
  .GetCustomAttributes(false) 
  .ToDictionary(a => a.GetType().Name, a => a);

如果您还想包含继承的属性，请记住从false更改为true。

如果你的意思是“对于带有一个参数的属性，列出属性名称和参数值”，那么在。net 4.5中通过CustomAttributeData API会更容易:

using System.Collections.Generic;
using System.ComponentModel;
using System.Reflection;

public static class Program
{
    static void Main()
    {
        PropertyInfo prop = typeof(Foo).GetProperty("Bar");
        var vals = GetPropertyAttributes(prop);
        // has: DisplayName = "abc", Browsable = false
    }
    public static Dictionary<string, object> GetPropertyAttributes(PropertyInfo property)
    {
        Dictionary<string, object> attribs = new Dictionary<string, object>();
        // look for attributes that takes one constructor argument
        foreach (CustomAttributeData attribData in property.GetCustomAttributesData()) 
        {

            if(attribData.ConstructorArguments.Count == 1)
            {
                string typeName = attribData.Constructor.DeclaringType.Name;
                if (typeName.EndsWith("Attribute")) typeName = typeName.Substring(0, typeName.Length - 9);
                attribs[typeName] = attribData.ConstructorArguments[0].Value;
            }

        }
        return attribs;
    }
}

class Foo
{
    [DisplayName("abc")]
    [Browsable(false)]
    public string Bar { get; set; }
}

我把它写进一个动态方法中，因为我在整个应用程序中使用了很多属性。方法:

public static dynamic GetAttribute(Type objectType, string propertyName, Type attrType)
    {
        //get the property
        var property = objectType.GetProperty(propertyName);

        //check for object relation
        return property.GetCustomAttributes().FirstOrDefault(x => x.GetType() == attrType);
    }

用法:

var objectRelAttr = GetAttribute(typeof(Person), "Country", typeof(ObjectRelationAttribute));

var displayNameAttr = GetAttribute(typeof(Product), "Category", typeof(DisplayNameAttribute));

希望这对大家有所帮助

这里有一些静态方法，可以用来获取MaxLength或任何其他属性。

using System;
using System.Linq;
using System.Reflection;
using System.ComponentModel.DataAnnotations;
using System.Linq.Expressions;

public static class AttributeHelpers {

public static Int32 GetMaxLength<T>(Expression<Func<T,string>> propertyExpression) {
    return GetPropertyAttributeValue<T,string,MaxLengthAttribute,Int32>(propertyExpression,attr => attr.Length);
}

//Optional Extension method
public static Int32 GetMaxLength<T>(this T instance,Expression<Func<T,string>> propertyExpression) {
    return GetMaxLength<T>(propertyExpression);
}


//Required generic method to get any property attribute from any class
public static TValue GetPropertyAttributeValue<T, TOut, TAttribute, TValue>(Expression<Func<T,TOut>> propertyExpression,Func<TAttribute,TValue> valueSelector) where TAttribute : Attribute {
    var expression = (MemberExpression)propertyExpression.Body;
    var propertyInfo = (PropertyInfo)expression.Member;
    var attr = propertyInfo.GetCustomAttributes(typeof(TAttribute),true).FirstOrDefault() as TAttribute;

    if (attr==null) {
        throw new MissingMemberException(typeof(T).Name+"."+propertyInfo.Name,typeof(TAttribute).Name);
    }

    return valueSelector(attr);
}

}

使用静态方法…

var length = AttributeHelpers.GetMaxLength<Player>(x => x.PlayerName);

或者在实例上使用可选的扩展方法…

var player = new Player();
var length = player.GetMaxLength(x => x.PlayerName);

或者对任何其他属性使用完整的静态方法(例如StringLength)…

var length = AttributeHelpers.GetPropertyAttributeValue<Player,string,StringLengthAttribute,Int32>(prop => prop.PlayerName,attr => attr.MaximumLength);

受到Mikael Engver回答的启发。

虽然上面得到最多好评的答案肯定有效，但我建议在某些情况下使用稍微不同的方法。

如果你的类有多个具有相同属性的属性，并且你想要将这些属性排序到字典中，下面是如何做的:

var dict = typeof(Book).GetProperties().ToDictionary(p => p.Name, p => p.GetCustomAttributes(typeof(AuthorName), false).Select(a => (AuthorName)a).FirstOrDefault());

这仍然使用强制转换，但确保强制转换始终有效，因为您将只获得“AuthorName”类型的自定义属性。 如果你有多个以上的属性，答案将得到一个强制转换异常。

private static Dictionary<string, string> GetAuthors()
{
    return typeof(Book).GetProperties()
        .SelectMany(prop => prop.GetCustomAttributes())
        .OfType<AuthorAttribute>()
        .ToDictionary(a => a.GetType().Name.Replace("Attribute", ""), a => a.Name);
}

使用泛型的示例(目标框架4.5)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

private static Dictionary<string, string> GetAttribute<TAttribute, TType>(
    Func<TAttribute, string> valueFunc)
    where TAttribute : Attribute
{
    return typeof(TType).GetProperties()
        .SelectMany(p => p.GetCustomAttributes())
        .OfType<TAttribute>()
        .ToDictionary(a => a.GetType().Name.Replace("Attribute", ""), valueFunc);
}

使用

var dictionary = GetAttribute<AuthorAttribute, Book>(a => a.Name);