1   Class cls = [self class];
 2   while (cls != [NSObject class])
 3   {
 4        unsigned int numberOfIvars = 0;
 5        Ivar* ivars = class_copyIvarList(cls, &numberOfIvars);//获取cls 类成员变量列表
 6        for(const Ivar* p = ivars; p < ivars+numberOfIvars; p++)//采用指针+1 来获取下一个变量
 7        {
 8            Ivar const ivar = *p;//取得这个变量
 9            const char *type = ivar_getTypeEncoding(ivar); //取得这个变量的类型
10            NSString *key = [NSString stringWithUTF8String:ivar_getName(ivar)];//取得这个变量的名称
11                 
12            NSLog(@"++ Name=\"%@\" Type=%@ Value=%@",key,[NSString stringWithUTF8String:type],[self valueForKey:key]);
13         }
14             cls = class_getSuperclass(cls);
15   }