我有一个对象,其属性可能为零.我应该如何在encodeWithCoder(和decodeWithCoder)中实现它？
- (void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:_duration forKey:kDuration]; //_duration could be nil
}
解决方法
- (void)encodeWithCoder:(NSCoder *)aCoder
{
if (_duration) {
[aCoder encodeObject:_duration forKey:kDuration]; //_duration could be nil
}
}
(如果密钥不存在,您的对象将在解码时为零.)
