.net中的反射

.Net单元测试工具Nunit就是使用的反射机制,在写测试用例的时候规定包含测试方法的类附加上"TestFixture"属性，测试方法附加"Test"属性。

NUnit首先从指定的Assembly中找到标记有"TestFixture"的Type.然后再遍历每一个Type找出标记有"Test"的方法MemberInfo. 调用方法只需使用 MemberInfo 实例的Invoke方法。

反射的一些常用功能

1. 获取实例的类型。例如

int i = 16;
Type type = i.GetType();
Console.WriteLine(type);

输出为 "System.Int32".

2.获取程序集的完整的名称

foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
{
     Console.WriteLine(assembly.FullName);
}

3.访问标记在类上的属性

Teacher teacher = new Teacher();
            Type type = teacher.GetType();
            Author author = Attribute.GetCustomAttribute(type, typeof(Author)) as Author;
            if (author != null)
            {
                Console.WriteLine(author.BookName);
            }

4. 访问标记在类中的方法上的属性以及调用方法

Teacher teacher = new Teacher();
            Type type = teacher.GetType();
            MethodInfo[] methodInfoArr = type.GetMethods(BindingFlags.Public | BindingFlags.DeclaredOnly | BindingFlags.Instance);
            Console.WriteLine(methodInfoArr.Length);
            foreach (MethodInfo methodInfo in methodInfoArr)
            {
                Console.WriteLine(methodInfo.Name);
                Usage Usage = Attribute.GetCustomAttribute(methodInfo, typeof(Usage)) as Usage;
                if (Usage != null)
                {

methodInfo.Invoke(Activator.CreateInstance(type), null);
                    Console.WriteLine(Usage.Description);
                }
            }

下面是定义的属性类和使用属性类的Teacher类

[Author("God is a girl")]
    public class Teacher
    {
        public string name;
        public string Name
        {
            get { return name; }
            set { name = value; }
        }

        public Teacher()
        {

        }

        [Usage("Invoke by a instance")]
        public void CallStudent()
        {
            Console.WriteLine("Calling student.....");
        }

        public static void CallSpeficStudent()
        {
            Console.WriteLine("Calling specific student.....");
        }
    }

    public class Author : Attribute
    {
        private string bookName;
        public string BookName
        {
            get { return bookName; }
            set { bookName = value; }
        }

        public Author(string bookName)
        {
            this.bookName = bookName;
        }
    }

    public class Usage : Attribute
    {
        private string description;
        public string Description
        {
            get { return description; }
            set { description = value; }
        }

        public Usage(string description)
        {
            this.description = description;
        }
    }

.Net单元测试工具Nunit就是使用的反射机制,字写测试用例的时候规定包含测试方法的类附加上"TestFixture"属性，测试方法附加"Test"属性。

NUnit首先从指定的Assembly中找到标记有"TestFixture"的Type.然后再遍历每一个Type找出标记有"Test"的方法MemberInfo. 调用方法只需使用 MemberInfo 实例的Invoke方法。