objective-c - 自定义类集合的 NSSecureCoding 问题

Question

我在采用 NSSecureCoding 时遇到了问题。我对一个包含自定义类对象的数组进行编码，该类正确地采用了 NSSecureCoding。当我解码它时，传递类 NSArray(这是我编码的对象的类)，它会抛出异常。但是，当用字符串数组做完全相同的事情时，它工作正常。我看不出我的类和 NSString 之间有什么区别。

#import <Foundation/Foundation.h>

@interface Foo : NSObject <NSSecureCoding>
@end
@implementation Foo
- (id)initWithCoder:(NSCoder *)aDecoder {
  return [super init];
}
- (void)encodeWithCoder:(NSCoder *)aCoder {
}
+ (BOOL)supportsSecureCoding {
  return YES;
}
@end

int main() {
  @autoreleasepool {

    NSMutableData* data = [[NSMutableData alloc] init];
    NSKeyedArchiver* archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    [archiver encodeObject:@[[Foo new]] forKey:@"foo"];
    [archiver encodeObject:@[@"bar"] forKey:@"bar"];
    [archiver finishEncoding];

    NSKeyedUnarchiver* unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
    unarchiver.requiresSecureCoding = YES;
    // throws exception: 'value for key 'NS.objects' was of unexpected class 'Foo'. Allowed classes are '{( NSArray )}'.'
    [unarchiver decodeObjectOfClass:[NSArray class] forKey:@"foo"];
    // but this line works fine:
    [unarchiver decodeObjectOfClass:[NSArray class] forKey:@"bar"];
    [unarchiver finishDecoding];

  }
  return 0;
}

Answer 1

您可能已经解决了这个问题，但我刚刚点击并找到了解决方案，我想我会把它留在这里给找到这个的其他人。

我的解决方案是使用 decodeObjectOfClasses:forKey:

迅速:

    if let data = defaults.objectForKey(FinderSyncKey) as? NSData
        let unArchiver = NSKeyedUnarchiver(forReadingWithData: data)
        unArchiver.setRequiresSecureCoding(true)
         //This line is most likely not needed, I was decoding the same object across modules
        unArchiver.setClass(CustomClass.classForCoder(), forClassName: "parentModule.CustomClass")
        let allowedClasses = NSSet(objects: NSArray.classForCoder(),CustomClass.classForCoder())
        if let unarchived = unArchiver.decodeObjectOfClasses(allowedClasses, forKey:NSKeyedArchiveRootObjectKey) as?  [CustomClass]{
            return unarchived

        }    
    }

在 objective-C 中它会像 [unArchiver decodeObjectOfClasses:allowedClasses forKey:NSKeyedArchiveRootObjectKey]

将解码对象更改为解码对象为我解决了上述异常。