Question

如何像其他对象一样对NSCalendarUnit进行编码和解码，例如

self.myStr = [decoder decodeObjectForKey:@"myStr"];
[encoder encodeObject:self.myStr forKey:@"myStr"];

尝试将NSCalendarUnit NSNumber保存在@(self.repetition); 64，但我在登录时收到NSCalendarUnit。

我想对if(xxxxx == NSCalendarUnit)进行编码并保存，以后需要对其进行解码并将其用于比较，如eval

Answer 1

NSCalendarUnit是一个选项集（NS_OPTIONS），这意味着NSCalendarUnit值可以是单位的无，一个或多个值。您需要执行bit mask if ((xxxx & NSCalendarUnitHour) != 0)来检查值。

您可以像现在一样对值进行编码，NSNumber并使用NSNumber.unsignedInteger在解码时获取值（请注意NSCalendarUnit的枚举定义为NSUInteger）。（注意，您还可以使用-[NSCoder encodeInteger:forKey:]将值存储为NSInteger。）

<强>序列化

[encoder encodeObject:@(self.repetition) forKey:@"repetition"];

<强> Deserialisation

self.repetition = [[decoder decodeObjectOfClass:[NSNumber class] 
                   forKey:@"repetition"] unsignedInteger];

<强>检查

if ((self.repetition & NSCalendarUnitHour) != 0) {
    // Do something
} else if ((self.repetition & NSCalendarUnitMinute) != 0) {
    // Do something
}

Answer 2

NSCalendarUnit是一个无符号长整数，所以它可以是＃34;盒装＆＃34; （在一个对象中）使用NSNumber上用于无符号长整数的两种方法：

NSCalendarUnit someNSCalendarUnit = NSCalendarUnitDay;
NSNumber *boxed = [NSNumber numberWithUnsignedLong:someNSCalendarUnit];

和

NSCalendarUnit unboxed = [boxed unsignedLongLongValue];
// now, unboxed == someNSCalendarUnit

您可能知道如何编码解码NSNumbers，只需在编码/解码方法中添加额外的步骤...

- (void)encodeWithCoder:(NSCoder*)encoder {
    [super encodeWithCoder:encoder];

    NSNumber *boxed = [NSNumber numberWithUnsignedLong:self.someNSCalendarUnit];
    [encoder encodeObject:boxed forKey:@"someNSCalendarUnit"];
    // ...

}

- (id)initWithCoder:(NSCoder*)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        NSNumber *boxed = [aDecoder decodeObjectForKey:@"someNSCalendarUnit"];
        _someNSCalendarUnit = [boxed unsignedLongLongValue];
        // ...
    }
    return self;
}

如何编码和解码NSCalendarUnit

2 个答案: