如何通过反射区分值类型、可空值类型、枚举、可空枚举、引用类型

Question

如何通过反射区分值类型、可空值类型、枚举、可空枚举、引用类型?

enum MyEnum
    {
        One,
        Two,
        Three
    }
    class MyClass
    {
        public int IntegerProp { get; set; }
        public int? NullableIntegerProp { get; set; }
        public MyEnum EnumProp { get; set; }
        public MyEnum? NullableEnumProp { get; set; }
        public MyClass ReferenceProp { get; set; }
    }
    class Program
    {
        static void Main(string[] args)
        {   
            Type classType = typeof(MyClass);
            PropertyInfo propInfoOne = classType.GetProperty("IntegerProp");
            PropertyInfo propInfoTwo = classType.GetProperty("NullableIntegerProp");
            PropertyInfo propInfoThree = classType.GetProperty("EnumProp");
            PropertyInfo propInfoFour = classType.GetProperty("NullableEnumProp");
            PropertyInfo propInfoFive = classType.GetProperty("ReferenceProp");
            propInfoOne.???
            ...............
            ...............
        }
    }

Where in the propInfo…这些信息可以检索吗?

Answer 1

如何检查枚举、可空类型、基本类型和值类型;

Console.WriteLine(propInfoOne.PropertyType.IsPrimitive); //true
Console.WriteLine(propInfoOne.PropertyType.IsValueType); //false, value types are structs
Console.WriteLine(propInfoThree.PropertyType.IsEnum); //true
var nullableType = typeof (Nullable<>).MakeGenericType(propInfoThree.PropertyType);
Console.WriteLine(nullableType.IsAssignableFrom(propInfoThree.PropertyType)); //true

注意值类型和原语是不同的东西。原语只是映射到类型的简写(例如bool> System.Boolean)。值类型按值传递;它们是结构体而不是类

Answer 2

    public void Test(Type desiredType, object value)
    {
        if (desiredType.IsGenericType)
        {
            if (desiredType.GetGenericTypeDefinition() == typeof(Nullable<>))
            {
                if (value == null)
                {
                }
            }
        }
    }

Answer 3

PropertyType.Name似乎为非空和可空类型提供了不同的输出。也许这能帮到你。

实际上它给出Nullable ' 1 Int32作为Nullable和Non Nullable的输出