runtime講解<二>

runtime的應用（1）

前面對runtime有了一個簡單瞭解，可看了半天在應用在沒什麼用啊，那你就錯了

啊，我想起來了，你前面不就要說應用嗎，爲毛等到如今，我還傻傻看完前一頁，流量啊，其實我是來替網通作任務的

還記得歸檔解檔嗎，想一想就心碎的不行啊，那一大堆的=啊，有了runtime立刻心就熱乎了

首先遵循NSCoding協議

//歸檔
- (void)encodeWithCoder:(NSCoder *)aCoder
{
	unsigned int count;
	//得到指向當前類的全部屬性的指針
	objc_property_t *propertys = class_copyPropertyList([Student class], &count);
	for (int i = 0;  i < count; i++) {
		//得到指向屬性的指針
		objc_property_t property = propertys[i];
		
		const char *name = property_getName(property);
		
		NSString *properyName = [NSString stringWithUTF8String:name];
		
		
		//經過名稱取值
		NSString *propertyValue = [self valueForKey:properyName];
		//編碼屬性
		[aCoder encodeObject:propertyValue forKey:properyName];
	}
	free(propertys);
}
//解檔
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
	
	unsigned int count;
	//得到指向當前類的全部屬性的指針
	objc_property_t *propertys = class_copyPropertyList([Student class], &count);
	for (int i = 0;  i < count; i++) {
		//得到指向屬性的指針
		objc_property_t property = propertys[i];
		
		const char *name = property_getName(property);
		
		NSString *properyName = [NSString stringWithUTF8String:name];
		
		//解碼屬性值
		NSString *propertyValue = [aDecoder decodeObjectForKey:properyName];
		
		[self setValue:propertyValue forKey:properyName];

	}
   free(propertys);

	
	return self;
}