IOS高级开发～Runtime（一）
一些公用类：
@interface CustomClass : NSObject
- (void) fun1;
@end
@implementation CustomClass
- (void) fun1
{
NSLog(@"fun1");
}
@end
@interface TestClass : NSObject
@end
@implementation TestClass
@end
别忘记引入库：#include<objc/runtime.h>
1、对象拷贝：id object_copy(id obj, size_t size)
- (void) copyObj
{
CustomClass *obj = [CustomClassnew];
NSLog(@"%p", &obj);
id objTest = object_copy(obj,sizeof(obj));
NSLog(@"%p", &objTest);
[objTest fun1];
}
打印结果：
2013-07-26 15:35:11.547 HighOC[6859:c07] 0xbfffdf64
2013-07-26 15:35:11.547 HighOC[6859:c07] 0xbfffdf60
2013-07-26 15:35:11.547 HighOC[6859:c07] 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)
- (void) objectDispose
{
CustomClass *obj = [CustomClassnew];
object_dispose(obj);
[obj release];
[obj fun1];
}
打印结果：程序crash
malloc: *** error for object 0x758e6d0: 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)
- (void) setClassTest
{
CustomClass *obj = [CustomClassnew];
[obj fun1];
Class aClass =object_setClass(obj, [CustomClassOtherclass]);
//obj 对象的类被更改了 swap the isa to an isa
NSLog(@"aClass:%@",NSStringFromClass(aClass));
NSLog(@"obj class:%@",NSStringFromClass([objclass]));
[obj fun2];
}
- (void) getClassTest
{
CustomClass *obj = [CustomClassnew];
Class aLogClass =object_getClass(obj);
NSLog(@"%@",NSStringFromClass(aLogClass));
}
4、获取对象的类名 constchar *object_getClassName(id obj)
- (void) getClassName
{
CustomClass *obj = [CustomClassnew];
NSString *className = [NSStringstringWithCString:object_getClassName(obj)encoding:NSUTF8StringEncoding];
NSLog(@"className:%@", className);
}
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);
}
/**
* 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);
}
相关文档及说明：
Obj-C的方法（method）就是一个至少需要两个参数（self，_cmd）的C函数
IMP有点类似函数指针，指向具体的Method实现。
向一个类动态添加方法
BOOL class_addMethod(Class cls, SEL name, IMP imp, const char *types)
参数说明：
cls：被添加方法的类
name：可以理解为方法名
imp：实现这个方法的函数
types：一个定义该函数返回值类型和参数类型的字符串
class_addMethod([TestClass class], @selector(ocMethod:), (IMP)testFunc, "i@:@");
其中types参数为"i@:@“，按顺序分别表示：
i：返回值类型int，若是v则表示void
@：参数id(self)
:：SEL(_cmd)
@：id(str)
官方文档：
https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/ObjCRuntimeRef/Reference/reference.html
https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html