举例说明，我们定义一个Person类，在一个ViewController 调用，获取该类的成员变量，属性列表，方法列表
定义Person类如下
#import <Foundation/Foundation.h>
@interface Person : NSObject
@property(nonatomic,copy) NSString *name;
@property(nonatomic,copy) NSString *sex;
-(NSString *)sayName;
-(NSString *)saySex;
-(void)updatePrivateName:(NSString *)name;
@end
//--------------------------------------
#import "Person.h"
/* Person.m 的实现
这里我对Person 进行了Class Extension
为了说明，属性和成员变量是两种不同的东西 */
@interface Person ()
{
NSString *privateName;
}
@end
@implementation Person
- (NSString *)saySex
{
return @"i am a boy";
}
- (NSString *)sayName
{
return @"my name is pengpeng";
}
/* 调用扩展属性必须的 -> 函数*/
-(void)updatePrivateName:(NSString *)name{
self ->privateName = name;
NSLog(@"NSLog privateName Value is %@",self->privateName);
}
/* 私有方法*/
-(void)private_func{
NSLog(@"privte function");
}
@end
然后在ViewController 引入Person，并创建一个对象，展示代码如下，应该都能看得懂；
上面Person 的定义还能延伸一下 Category 和Extension的区别， 以及@Property 自动帮我们实现了Set 、Get 方法;
- (void)viewDidLoad {
[super viewDidLoad];
self.person = [Person new];
_person.name = @"big pengpeng";
self.person.sex = @"man";
/* 调用方法*/
[self getPropertyList];
[self getMethodList];
[self getIvarList];
/* 延伸，扩展属性的调用*/
[self.person updatePrivateName:@"pengpeng"];
}
/* 获取属性列表*/
-(void)getPropertyList{
unsigned int count;
objc_property_t *propertyList = class_copyPropertyList([Person class], &count);
for (unsigned int i=0; i<count; i++) {
const char *propertyName = property_getName(propertyList[i]);
NSLog(@"property---->%@", [NSString stringWithUTF8String:propertyName]);
}
}
/* 运行结果*/
runtime[41582:1275679] property---->name
runtime[41582:1275679] property---->sex
/* */
-(void)getMethodList{
unsigned int count;
Method *methodList = class_copyMethodList([Person class], &count);
for (unsigned int i; i<count; i++) {
Method method = methodList[i];
NSLog(@"method---->%@", NSStringFromSelector(method_getName(method)));
}
}
/* 运行结果*/
runtime[41582:1275679] method---->sayName
runtime[41582:1275679] method---->saySex
runtime[41582:1275679] method---->updatePrivateName:
runtime[41582:1275679] method---->private_func
runtime[41582:1275679] method---->.cxx_destruct
runtime[41582:1275679] method---->name
runtime[41582:1275679] method---->setName:
runtime[41582:1275679] method---->setSex:
runtime[41582:1275679] method---->sex
出现这个结果应该也没有什么问题；sayName、saySex、updatePrivateName都是对象方法,private_func是私有方法；
属性name、sex 因为是Property声明的默认实现了set 和get方法；
.cxx_destruct 是ARC下将所有的成员变量变成nil的方法（系统加的）
/* 获取成员变量列表*/
-(void)getIvarList{
unsigned int count;
Ivar *ivarList = class_copyIvarList([Person class], &count);
for (unsigned int i; i<count; i++) {
Ivar myIvar = ivarList[i];
const char *ivarName = ivar_getName(myIvar);
NSLog(@"Ivar---->%@", [NSString stringWithUTF8String:ivarName]);
}
}
/* 运行结果*/
runtime[45997:1632709] Ivar---->privateName
runtime[45997:1632709] Ivar---->_name
runtime[45997:1632709] Ivar---->_sex
/* 在该ViewController 实现一个AlertView 的代理方法*/
-(void)createAlertView{
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"title" message:@"message" delegate:self cancelButtonTitle:@"cancel" otherButtonTitles:@"comfirm", nil];
[alertView show];
}
-(void)getProtocolList{
unsigned int count;
__unsafe_unretained Protocol **protocolList = class_copyProtocolList([self class], &count);
for (unsigned int i; i<count; i++) {
Protocol *myProtocal = protocolList[i];
const char *protocolName = protocol_getName(myProtocal);
NSLog(@"protocol---->%@", [NSString stringWithUTF8String:protocolName]);
}
}
/*运行结果*/
runtime[17235:552811] protocol---->UIAlertViewDelegate
进入runtime 的头文件，可以看到runtime 提供了很多API 给我们使用，其中就有可以动态的给一个Class添加方法;
这里同样给Person 类，添加一个-(void)syGoodBye{} 方法
其实还有关于动态添加方法的另一种形势，链接如下 链接
/* 定义一个方法*/
- (void)sayFrom
{
class_addMethod([self.person class], @selector(guess), (IMP)guessAnswer, "v@:");
if ([self.person respondsToSelector:@selector(guess)]) {
[self.person performSelector:@selector(guess)];
} else{
NSLog(@"Sorry,I don't know");
}
self.textview.text = @"beijing";
}
void guessAnswer(id self,SEL _cmd){
NSLog(@"i am from beijing");
}
/* 调用该方法*/
- (void)viewDidLoad {
[super viewDidLoad];
self.person = [Person new];
[self sayFrom];
}
/* 运行结果*/
runtime[45997:1632709] i am from beijing
还是以Person 对象为例子，正常情况调用Person 对象的sayName 方法和saySex 都没毛病，如果我们在load方法或者在viewDidLoad 方法中，将两个方法交换，那么就能实现方法交换；
- (void)viewDidLoad {
[super viewDidLoad];
self.person = [Person new];
NSLog(@"%@",_person.sayName);
NSLog(@"%@",_person.saySex);
Method m1 = class_getInstanceMethod([self.person class], @selector(sayName));
Method m2 = class_getInstanceMethod([self.person class], @selector(saySex));
method_exchangeImplementations(m1, m2);
}
- (IBAction)sayName:(id)sender {
NSLog(@"方法交换后 sayName : %@",[_person sayName]);
}
- (IBAction)saySex:(id)sender {
NSLog(@"方法交换后 saySex : %@",[_person saySex]);
}
/*运行结果*/
runtime[45997:1632709] my name is pengpeng
runtime[45997:1632709] i am a boy
//方法交换后
runtime[46307:1667781] 方法交换后 sayName : i am a boy
runtime[46307:1667781] 方法交换后 saySex : my name is pengpeng
举例，这里给UIImageview 添加一个属性 URLkey；
创建一个 UIImageView+Extension 分类;
代码如下
#import <UIKit/UIKit.h>
#import <objc/runtime.h>
@interface UIImageView (extension)
@property (nonatomic,copy) NSString *URLkey;
@end
//---------------------------
#import "UIImageView+extension.h"
static char * UrlKey = "imageUrlKey";
@implementation UIImageView (extension)
-(NSString *)URLkey{
return objc_getAssociatedObject(self, UrlKey);
}
-(void)setURLkey:(NSString *)URLkey{
objc_setAssociatedObject(self, UrlKey, URLkey, OBJC_ASSOCIATION_COPY_NONATOMIC);
}
/* 运行 */
- (void)viewDidLoad {
[super viewDidLoad];
UIImageView *imageview = [[UIImageView alloc]init];
imageview.URLkey = @"我是一个假的URL";
NSLog(@" %@",imageview.URLkey);
}
/*运行结果*/
runtime[49010:1741011] 我是一个假的URL
利用runtime完成字典转模型的功能，其实就是给 NSObject 扩展一个字典转模型的方法，因为所有的类都是NSObject的子类，获取字典内部ivar成员变量，字典通过成员变量对应的Key取出Value ,然后把value 赋值给模型相映的属性；
如果属性是另一个自定义Class，则再次递归直到解析完毕；
如果属性是一个数组，则便利数组的每个对象循环解析处理成模型数组 赋值给相映的属性值；
// 字典转模型
+ (instancetype)objectWithDict:(NSDictionary *)dict
{
// 创建对应模型对象
id objc = [[self alloc] init];
unsigned int count = 0;
// 1.获取成员属性数组
Ivar *ivarList = class_copyIvarList(self, &count);
// 2.遍历所有的成员属性名,一个一个去字典中取出对应的value给模型属性赋值
for (int i = 0; i < count; i++) {
// 2.1 获取成员属性
Ivar ivar = ivarList[i];
// 2.2 获取成员属性名 C -> OC 字符串
NSString *ivarName = [NSString stringWithUTF8String:ivar_getName(ivar)];
// 2.3 _成员属性名 => 字典key
NSString *key = [ivarName substringFromIndex:1];
// 2.4 去字典中取出对应value给模型属性赋值
id value = dict[key];
// 获取成员属性类型
NSString *ivarType = [NSString stringWithUTF8String:ivar_getTypeEncoding(ivar)];
// 二级转换,字典中还有字典,也需要把对应字典转换成模型
//
// 判断下value,是不是字典
if ([value isKindOfClass:[NSDictionary class]] && ![ivarType containsString:@"NS"]) { // 是字典对象,并且属性名对应类型是自定义类型
// user User
// 处理类型字符串 @\"User\" -> User
ivarType = [ivarType stringByReplacingOccurrencesOfString:@"@" withString:@""];
ivarType = [ivarType stringByReplacingOccurrencesOfString:@"\"" withString:@""];
// 自定义对象,并且值是字典
// value:user字典 -> User模型
// 获取模型(user)类对象
Class modalClass = NSClassFromString(ivarType);
// 字典转模型
if (modalClass) {
// 字典转模型 user
value = [modalClass objectWithDict:value];
}
}
// 三级转换：NSArray中也是字典，把数组中的字典转换成模型.
// 判断值是否是数组
if ([value isKindOfClass:[NSArray class]]) {
// 判断对应类有没有实现字典数组转模型数组的协议
if ([self respondsToSelector:@selector(arrayContainModelClass)]) {
// 转换成id类型，就能调用任何对象的方法
id idSelf = self;
// 获取数组中字典对应的模型
NSString *type = [idSelf arrayContainModelClass][key];
// 生成模型
Class classModel = NSClassFromString(type);
NSMutableArray *arrM = [NSMutableArray array];
// 遍历字典数组，生成模型数组
for (NSDictionary *dict in value) {
// 字典转模型
id model = [classModel objectWithDict:dict];
[arrM addObject:model];
}
// 把模型数组赋值给value
value = arrM;
}
}
// 2.5 KVC字典转模型
if (value) {
[objc setValue:value forKey:key];
}
}
// 返回对象
return objc;
}
我们直到 要实现自定义对象，归档和解档的功能，只需给类，实现 协议即可，但是每次都要给归档的对象写这些协议的实现，是不是有点费劲，那么今天我们来看一下runtime如何实现自动归档解档；
首先没有对比就没有伤害，我们来看之前是怎么实现归档解档的
/* 手动实现-没什么好说的是吧*/
@interface Movie : NSObject<NSCoding>
@property (nonatomic, copy) NSString *movieId;
@property (nonatomic, copy) NSString *movieName;
@property (nonatomic, copy) NSString *pic_url;
@end
//-----------
@implementation Movie
- (void)encodeWithCoder:(NSCoder *)encoder
{
[encoder encodeObject:self.movieId forKey:@"movieId"];
[encoder encodeObject:self.movieName forKey:@"movieName"];
[encoder encodeObject:self.pic_url forKey:@"pic_url"];
}
- (id)initWithCoder:(NSCoder *)decoder
{
self.movieId = [aDecoder decodeObjectForKey:@"movieId"];
self.movieName = [aDecoder decodeObjectForKey:@"movieName"];
self.pic_url = [aDecoder decodeObjectForKey:@"pic_url"];
}
利用Runtime 实现实现Movie对象的 自动归档和解档；
demo 中该实现方法写在Moive的 .m 文件中，实际项目中，给需要归档和解档的对象定义一个基类BaseArchiveModel实现该Runtime的 - (void)encodeWithCoder:(NSCoder *)encoder和- (id)initWithCoder:(NSCoder *)decoder方法自动归档接档，项目中需要归档解档的类只需继承该BaseArchiveModel就可以了；
@implementation Movie
- (void)encodeWithCoder:(NSCoder *)encoder
{
unsigned int count = 0;
Ivar *ivars = class_copyIvarList([Movie class], &count);
for (int i = 0; i<count; i++) {
Ivar ivar = ivars[i];
const char *name = ivar_getName(ivar);
NSString *key = [NSString stringWithUTF8String:name];
id value = [self valueForKey:key];
[encoder encodeObject:value forKey:key];
}
free(ivars);
}
- (id)initWithCoder:(NSCoder *)decoder
{
if (self = [super init]) {
unsigned int count = 0;
Ivar *ivars = class_copyIvarList([Movie class], &count);
for (int i = 0; i<count; i++) {
Ivar ivar = ivars[i];
const char *name = ivar_getName(ivar);
NSString *key = [NSString stringWithUTF8String:name];
id value = [decoder decodeObjectForKey:key];
[self setValue:value forKey:key];
}
free(ivars);
}
return self;
}
项目链接 https://github.com/hunter858/runtime
https://github.com/CoderMJLee/MJExtension
https://github.com/ibireme/YYModel
https://github.com/SDWebImage/SDWebImage
https://github.com/chenfanfang/AvoidCrash
未完待续，整理中...