ios - objective-c NSString *属性保留计数奇数

我有以下示例类:

Test.h:

@interface Test : UIButton {
    NSString *value;
}
- (id)initWithValue:(NSString *)newValue;
@property(copy) NSString *value;

Test.m:

@implementation Test
@synthesize value;
- (id)initWithValue:(NSString *)newValue {
    [super init];
    NSLog(@"before nil value has retain count of %d", [value retainCount]);
    value = nil;
    NSLog(@"on nil value has retain count of %d", [value retainCount]);
    value = newValue;
    NSLog(@"after init value has retain count of %d", [value retainCount]);
    return self;
}

产生以下输出:

2008-12-31 09:31:41.755 Concentration[18604:20b] before nil value has retain count of 0
2008-12-31 09:31:41.756 Concentration[18604:20b] on nil value has retain count of 0
2008-12-31 09:31:41.757 Concentration[18604:20b] after init value has retain count of 2147483647

我这样称呼它:

Test *test = [[Test alloc] initWithValue:@"some text"];

值不应该保留计数为1吗？我想念什么？

谢谢你的帮助。

最佳答案

您已经引用了一个不可变的字符串。赋值不需要复制值(字符串数据)，因为它是不可变的。如果您执行可变操作，例如value = [newValue uppercaseString]，则它应该将这些位复制到value中，并且value的保留计数会增加。

关于ios - objective-c NSString *属性保留计数奇数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/403112/