iOS反射机制：objc_property_t的使用

#import <objc/runtime.h>

需要导入这个头文件。

• 动态获取一个自定义类对象中的所有属性

  - (NSDictionary *)allProperties
  {
      NSMutableDictionary *props = [NSMutableDictionary dictionary];
      unsigned int outCount, i;
      objc_property_t *properties = class_copyPropertyList([self class], &outCount);
      for (i = 0; i<outCount; i++)
      {
          objc_property_t property = properties[i];
          const char *char_f =property_getName(property);
          NSString *propertyName = [NSString stringWithUTF8String:char_f];
          id propertyValue = [self valueForKey:(NSString *)propertyName];
          if (propertyValue)
              [props setObject:propertyValue forKey:propertyName];
      }
      free(properties);
      return props;
  }
  

• 实现对象的自动赋值

  - (BOOL)reflectDataFromOtherObject:(NSObject*)dataSource
  
  {
      BOOL ret = NO;
      //propertyKeys 其实就是上面的方法的变形，上面方法回传一个可变字典，这里是得到一个可变数组的一个处理
      for (NSString *key in [self propertyKeys])
      {
      if ([dataSource isKindOfClass:[NSDictionary class]])
        {
      ret = ([dataSource valueForKey:key]==nil)?NO:YES;
        }
      else
        {
      ret = [dataSource  respondsToSelector:NSSelectorFromString(key)];
        }
      if (ret)
        {
      id propertyValue = [dataSource valueForKey:key];
      //该值不为NSNULL，并且也不为nil
      if (![propertyValue isKindOfClass:[NSNull class]] && propertyValue!=nil)
           {
      [self setValue:propertyValue forKey:key];
           }
         }
      }
  return ret;
  }