创建公共类：

@interface CustomClass : NSObject

- (void) fun1;

@end

@implementation CustomClass

-(void)fun1

{

    NSLog(@"fun1");

}

@end

@interface TestClass : NSObject

@end

@implementation TestClass

@end

1、对象拷贝：id object_copy(id obj, size_t size)

CustomClass * obj = [CustomClass new];

        NSLog(@"%p",&obj);

        id objTest = object_copy(obj, sizeof(obj));

        NSLog(@"%p",&objTest);

        [objTest fun1];

打印结果：

2014-10-20 09:51:48.973 runtimetest[2573:303] 0x7fff5fbff818

2014-10-20 09:51:48.983 runtimetest[2573:303] 0x7fff5fbff810

2014-10-20 09:51:48.984 runtimetest[2573:303] fun1

说明：

object_copy 函数实现了对象的拷贝。

2、对象释放 id object_dispose(id obj)

object_dispose(objTest);

        [objTest release];

runtimetest(2791,0x7fff791b2310) malloc: *** error for object 0x100202950: pointer being freed was not allocated

3、更改对象的类／获取对象的类Class object_setClass(id obj, Class cls)  ／ Class object_getClass(id obj)

        CustomClass * obj = [CustomClass new];

        [obj fun1];

        Class aClass = object_setClass(obj, [CustomClassOther class]);

        NSLog(@"aClass:%@",NSStringFromClass(aClass));

        NSLog(@"obj class:%@",NSStringFromClass([obj class]));

        [obj fun2];

运行结果：

2014-10-20 10:09:24.619 runtimetest[3536:303] aClass:CustomClass

2014-10-20 10:09:24.619 runtimetest[3536:303] obj class:CustomClassOther

2014-10-20 10:09:24.620 runtimetest[3536:303] fun2

CustomClass * obj = [CustomClass new];

        Class objClass = object_getClass(obj);

        NSLog(@"%@",NSStringFromClass(objClass));

运行结果：

2014-10-20 10:12:34.047 runtimetest[3726:303] CustomClass

4、获取对象的类名  constchar *object_getClassName(id obj)

CustomClass * obj = [CustomClass new];

        NSString * className =[NSString stringWithCString:object_getClassName(obj) encoding:NSUTF8StringEncoding];

        NSLog(@"%@",className);

运行结果:

2014-10-20 10:22:54.514 runtimetest[4160:303] CustomClass

5、给一个类添加方法  

BOOL class_addMethod(Class cls,SEL name,IMP imp, 

const char *types)

/**

  * 一个参数

  *

  */

int cfunction(id self, SEL _cmd, NSString *str) {

    NSLog(@"%@", str);

    return10;//随便返回个值

}

- (void) oneParam {

    TestClass *instance = [[TestClassalloc]init];

    //    方法添加

    class_addMethod([TestClassclass],@selector(ocMethod:), (IMP)cfunction,"i@:@");

    if ([instance respondsToSelector:@selector(ocMethod:)]) {

        NSLog(@"Yes, instance respondsToSelector:@selector(ocMethod:)");

    } else

    {

        NSLog(@"Sorry");

    }

    int a = (int)[instanceocMethod:@"我是一个OC的method，C函数实现"];

    NSLog(@"a:%d", a);

}

2014-10-20 10:47:25.738 runtimetest[5333:303] Yes, instance respondsToSelector:@selector(ocMethod:)

2014-10-20 10:47:25.748 runtimetest[5333:303] 我是一个OC的method，C函数实现

2014-10-20 10:47:25.749 runtimetest[5333:303] a:10

 /**

  * 两个参数

  *

  */

int cfunctionA(id self, SEL _cmd, NSString *str, NSString *str1) {

    NSLog(@"%@-%@", str, str1);

    return20;//随便返回个值

}

- (void) twoParam {

    TestClass *instance = [[TestClassalloc]init];

    class_addMethod([TestClassclass],@selector(ocMethodA::), (IMP)cfunctionA,"i@:@@");

    if ([instance respondsToSelector:@selector(ocMethodA::)]) {

        NSLog(@"Yes, instance respondsToSelector:@selector(ocMethodA::)");

    } else

    {

        NSLog(@"Sorry");

    }

    int a = (int)[instanceocMethodA:@"我是一个OC的method，C函数实现" :@"-----我是第二个参数"];

    NSLog(@"a:%d", a);

}

ios高级开发，runtime（一）