Runtime, 一套比较底层的C语言的库, 是OC的底层实现
使用场景:
- 利用RunTimer,在程序运行的时候, 动态创建一个类
- 利用RunTimer,在程序运行的时候, 动态为某个类添加,修改属性 / 方法
- 遍历一个类的属性, 方法, 成员变量
导入头文件 #import<objc/RunTime.h>
typedef struct objc_method *Method; //代表方法
typedef struct objc_ivar *Ivar; 代表成员变量
1. 对象归档/接档
自定义对象归档必须遵守协议<NSCoding>
- (instancetype)initWithCoder:(NSCoder*)coder
{
self= [superinit];
if(self) {
NSArray*array = [selfgetAllproperty];
for(NSString*propertyinarray) {
[selfsetValue:[coderdecodeObjectForKey:property]forKey:property];
}
//self.name = [coder decodeObjectForKey:@"name"];
//self.age = [[coder decodeObjectForKey:@"age"] intValue];
}
returnself;
}
- (void)encodeWithCoder:(NSCoder*)coder
{
//[coder encodeObject:self.name forKey:@"name"];
//[coder encodeObject:@(self.age) forKey:@"age"];
NSArray*array = [selfgetAllproperty];
for(NSString*propertyinarray) {
[coderencodeObject:[selfvalueForKey:property]forKey:property];
}
}
- (NSArray*)getAllproperty{
NSMutableArray*arr = [NSMutableArrayarray];
unsignedintcount =0;
objc_property_t*ivars =class_copyPropertyList([Personclass], &count);
for(inti =0; i
objc_property_tvar = ivars[i];
constchar*name =property_getName(var);
[arraddObject:[NSStringstringWithFormat:@"%s",name]];
}
returnarr;
}
Person*p = [[Personalloc]init];
p.name=@"eqefadv";
NSString*tempPath =NSTemporaryDirectory();
//存的是二进制,什么格式无所谓
NSString*fileP = [tempPathstringByAppendingPathComponent:@"xueshan.txt"];
//归档
[NSKeyedArchiver archiveRootObject: ptoFile:fileP];
//解档
Person*p = [NSKeyedUnarchiver unarchiveObjectWithFile:fileP];
2. 方法欺骗
//改变方法指针的指向, 从而交换方法实现
//load方法在main方法之前调用
+ (void)load{
Methodm1 =class_getClassMethod([NSURLclass],@selector(URLWithString:));
Methodm2 =class_getClassMethod([NSURLclass],@selector(xs_URLWithString:));
method_exchangeImplementations(m1, m2);
}
+ (instancetype)xs_URLWithString:(NSString*)URLString{
NSURL*url = [NSURL xs_URLWithString:URLString];
if(!url) {
NSLog(@"url为空的");
}
return url;
}
runtime的始终用法大全: http://www.jianshu.com/p/3182646001d1
