1. 动态变量控制
Teacher: What's your name?
XiaoMing: My name is XiaoMing.
Teacher: Pardon?
XiaoMing: My name is __
在程序当中，假设XiaoMing的name原来的值为XiaoMing，后来被Runtime偷换了一个名字叫Minggo。那么，Runtime是如何做到的呢？
①动态获取XiaoMing类中的所有属性[当然包括私有]
Ivar *ivar = class_copyIvarList([self.xiaoMing class], &count);
②遍历属性找到对应name字段
const char *varName = ivar_getName(var);
③修改对应的字段值成Minggo
object_setIvar(self.xiaoMing, var, @"Minggo");
-(void)answer{
unsigned int count = 0;
Ivar *ivar = class_copyIvarList([self.xiaoMing class], &count);
for (int i = 0; i<count; i++){
Ivar var = ivar[i];
const char *varName = ivar_getName(var);
NSString *name = [NSString stringWithUTF8String:varName];
if ([name isEqualToString:@"_englishName"]) {
object_setIvar(self.xiaoMing, var, @"Minggo");
break;
}
}
NSLog(@"XiaoMing first answer is %@",self.xiaoMing.englishName);
self.nameTf.text = self.xiaoMing.englishName;
}
