PropertyInfo如何實現(xiàn)深層屬性訪問

在C#中，可以使用PropertyInfo類實現(xiàn)深層屬性訪問。首先，獲取對象的類型信息，然后使用GetProperty方法獲取指定屬性的PropertyInfo對象，再遞歸地獲取嵌套屬性的PropertyInfo對象，直到達到需要訪問的深層屬性。

以下是一個示例代碼，演示如何使用PropertyInfo實現(xiàn)深層屬性訪問：

using System;
using System.Reflection;

public class Person
{
    public string Name { get; set; }
    public Address Address { get; set; }
}

public class Address
{
    public string Street { get; set; }
    public string City { get; set; }
}

class Program
{
    static void Main()
    {
        Person person = new Person
        {
            Name = "John Doe",
            Address = new Address
            {
                Street = "123 Main St",
                City = "City"
            }
        };

        PropertyInfo propertyInfo = GetDeepPropertyInfo(person, "Address.City");
        if (propertyInfo != null)
        {
            object propertyValue = GetDeepPropertyValue(person, "Address.City");
            Console.WriteLine(propertyInfo.Name + ": " + propertyValue);
        }
    }

    static PropertyInfo GetDeepPropertyInfo(object obj, string propertyName)
    {
        Type type = obj.GetType();
        string[] propertyNames = propertyName.Split('.');

        PropertyInfo propertyInfo = null;
        foreach (string name in propertyNames)
        {
            propertyInfo = type.GetProperty(name);
            if (propertyInfo != null)
            {
                type = propertyInfo.PropertyType;
            }
            else
            {
                return null;
            }
        }

        return propertyInfo;
    }

    static object GetDeepPropertyValue(object obj, string propertyName)
    {
        Type type = obj.GetType();
        string[] propertyNames = propertyName.Split('.');

        object propertyValue = null;
        foreach (string name in propertyNames)
        {
            PropertyInfo propertyInfo = type.GetProperty(name);
            if (propertyInfo != null)
            {
                propertyValue = propertyInfo.GetValue(obj);
                obj = propertyValue;
                type = propertyInfo.PropertyType;
            }
            else
            {
                return null;
            }
        }

        return propertyValue;
    }
}

在上面的示例中，GetDeepPropertyInfo和GetDeepPropertyValue方法分別用于獲取深層屬性的PropertyInfo對象和屬性值。通過使用這兩個方法，可以實現(xiàn)對任意深層屬性的訪問。