Description格式化

runtime class 属性

// ...
#import <objc/runtime.h>
// ...

- (NSString *)description{
   unsigned int count ,i;
   objc_property_t *propertyArray = class_copyPropertyList([self class], &count);
   NSMutableDictionary *tmpDic = [NSMutableDictionary dictionary];
   for (i = 0; i < count; i++) {
       objc_property_t property = propertyArray[i];
       NSString *proKey = [NSString stringWithCString:property_getName(property) encoding:NSUTF8StringEncoding];
       id proValue = [self valueForKey:proKey];
       
       if (proValue) {
           [tmpDic setObject:proValue forKey:proKey];
       } else {
           [tmpDic setObject:@"" forKey:proKey];
       }
   }
   free(propertyArray);
   return  [NSString stringWithFormat:@"%@: %p, \n%@", [self class], self, tmpDic];
}