objective-c – Obj-C,’self’未设置为'[(super或self)init
发布时间:2020-12-14 18:13:45 所属栏目:百科 来源:网络整理
导读:我知道我不久前问了一个类似的问题,但我仍然有点不确定.同样的事情发生在几个地方. ‘self’时使用的实例变量未设置为'[(super或self)init …]的结果 一个 - (id)initWithCoder:(NSCoder *)decoder { if (![super init]) return nil; red = [decoder decodeF
我知道我不久前问了一个类似的问题,但我仍然有点不确定.同样的事情发生在几个地方.
‘self’时使用的实例变量未设置为'[(super或self)init …]的结果 一个 - (id)initWithCoder:(NSCoder *)decoder { if (![super init]) return nil; red = [decoder decodeFloatForKey:kRedKey]; //occurs here green = [decoder decodeFloatForKey:kGreenKey]; blue = [decoder decodeFloatForKey:kBlueKey]; return self; } 乙 - (id)initWithFrame:(CGRect)frame title:(NSString*)str sideUp:(BOOL)up{ if(![super initWithFrame:frame]) return nil; int y; UIImage *img; if(up){ img = [UIImage imageNamedTK:@"TapkuLibrary.bundle/Images/graph/popup"]; y = 5; }else{ img = [UIImage imageNamedTK:@"TapkuLibrary.bundle/Images/graph/popdown"]; y = 14; } background = [[UIImageView alloc] initWithImage:img]; // occurs here C - (id) initWithFrame:(CGRect)frame { if(![super initWithFrame:frame]) return nil; UILabel *titleBackground = [[[UILabel alloc] initWithFrame: CGRectMake(0,480,40)] autorelease]; titleBackground.backgroundColor = [UIColor whiteColor]; [self addSubview:titleBackground]; titleLabel = [[UILabel alloc] initWithFrame:CGRectZero]; // occurs here 对于块A,这是正确的 self = [self init]; if( self != nil ) { 和B& C - (id) initWithFrame:(CGRect)frame { super = [super initWithFrame:frame] if(super != nil) { 解决方法
一般来说,你应该写:
self = [super init...]; // Potentially change "self" if (self) { something = x; another = y; } return self; 这是因为在某些情况下init可能不会返回原始的self值. (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |