OC获取UITextField的成员变量的方法

#import <objc/runtime.h>
	unsigned int count;
 	Ivar *ivarList =  class_copyIvarList([UITextField class], &count);
 	for (int i=0; i< count; i++) {
        Ivar ivar = ivarList[i];
        NSLog(@"%s",ivar_getName(ivar));
    }
    free(ivarList);