Ios 这个NSMutableArray有什么问题?
当我尝试时: PINQuote*quote=[[PINQuote alloc]init]; [quote.lines addObject:@“测试字符串”] 数组仍然为零Ios 这个NSMutableArray有什么问题?,ios,objective-c,Ios,Objective C,当我尝试时: PINQuote*quote=[[PINQuote alloc]init]; [quote.lines addObject:@“测试字符串”] 数组仍然为零 有什么想法吗?在实施中添加以下内容: @interface PINQuote : NSObject @property (nonatomic, strong) NSMutableArray *lines; @property (nonatomic, strong) NSString *quoteID; @property (n
有什么想法吗?在实施中添加以下内容:
@interface PINQuote : NSObject
@property (nonatomic, strong) NSMutableArray *lines;
@property (nonatomic, strong) NSString *quoteID;
@property (nonatomic, strong) NSString *customerName;
@end
或者,如果您不喜欢延迟加载:
- (NSMutableArray *)lines
{
if (!_lines) // Lazy load the mutable array when asked for.
_lines = [NSMutableArray array];
return _lines;
}
您只声明了该属性。现在必须创建它。尝试延迟实例化: PINQuote.m
- (id)init
{
self = [super init];
if (self) {
_lines = [NSMutableArray array]; // Eager load the mutable array.
}
return self;
}
初始化对象时,它不会神奇地创建自己。您需要为数组指定一个值。
- (NSMutableArray*)lines {
if (!_lines)
_lines = [NSMutableArray array];
return _lines;
}