最近在使用initWithCoder中遇到了野指针的问题;
情形如下：
父类的initwithcoder:
- (id)initWithCoder:(NSCoder *)aDecoder{
NSDictionary *info = [aDecoder decodeObjectForKey:@"info"];
self = [[YFModel alloc]initWithInfo:info];
return self;
}
子类的initithcoder:
- (id)initWithCoder:(NSCoder *)aDecoder{
self = [super initWithCoder:aDecoder];
if (self){
_newsTitle = [aDecoder decodeObjectForKey:@"newstitle"];
_newsDescription = [aDecoder decodeObjectForKey:@"newsDescription"];
_newsID = [aDecoder decodeObjectForKey:@"newsID"];
_thumb = [aDecoder decodeObjectForKey:@"thumb"];
_newsEditor = [aDecoder decodeObjectForKey:@"newsEditro"];
_newsDetail = [aDecoder decodeObjectForKey:@"newsDetail"];
}
return self;
}
调试中出现如下错误：
执行
_newsTitle = [aDecoder decodeObjectForKey:@"newstitle"];
时遇到野指针问题。原因是父类的初始话方法中执行了
self = [[YFModel alloc]initWithInfo:info];
，对内存空间重新分配，子类
self = [super initWithCoder:aDecoder];
得到的指针为父类类型，内存中没有
_newsTitle_newsDescription_newsID_thumb_newsEditor_newsDetail
这些实例变量，所以报错。更改方法，在父类的初始化方法中万万不能alloc
- (id)initWithCoder:(NSCoder *)aDecoder{
self = [super init];
_info = [aDecoder decodeObjectForKey:@"info"];
return self;
}
改正这样既可。