Question

在iOS 12中，不建议使用archiveRootObject：toFile:。有人能建议一种简化的替代方法来将对象归档到文件吗？

c.execute("""SELECT num from tb_numbers""")
table = c.fetchall()

x = 1

for each_value in table:
    if each_value[0] == x:
        print("Yeah! Find: {0}".format(each_value[0]))

Answer 1

与suggested by Apple一样，我们应该使用 FileManager 读取/写入存档文件。

guard let documentURL = FileManager().urls(for: .documentDirectory, in: .userDomainMask).first else { return }

let filePath = "MyArchive.data"
let fileURL = documentURL.appendingPathComponent(filePath)

// Archive
if let dataToBeArchived = try? NSKeyedArchiver.archivedData(withRootObject: myObject, requiringSecureCoding: true) {
    try? dataToBeArchived.write(to: fileURL)
}

// Unarchive
if let archivedData = try? Data(contentsOf: fileURL),
        let myObject = (try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(archivedData)) as? Object {
    /// Do anything with the unarchived object
    ///
    ///
}

Answer 2

感谢@vadian的提示，以下是我想在iOS 12下进行归档和取消归档的内容：

NSError *error = nil;

NSString *docsDir;
NSArray *dirPaths;

//Get the device's data directory:
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
NSString *databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:@"appData.data"]];

//Archive using iOS 12 compliant coding:
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:@"foo" requiringSecureCoding:NO error:&error];
[data writeToFile:databasePath options:NSDataWritingAtomic error:&error];
NSLog(@"Write returned error: %@", [error localizedDescription]);

//Unarchive the data:
NSData *newData = [NSData dataWithContentsOfFile:databasePath];
NSString *fooString = [NSKeyedUnarchiver unarchivedObjectOfClass:[NSString class] fromData:newData error:&error];

Answer 3

替换为archivedDataWithRootObject:requiringSecureCoding:error:

+ (NSData *)archivedDataWithRootObject:(id)object 
             requiringSecureCoding:(BOOL)requiresSecureCoding 
                             error:(NSError * _Nullable *)error;

加上额外的步骤将数据写入磁盘。

请参阅Foundation iOS 11.4 to 12.0 API Differences

Answer 4

unArchivedObjectOfClass在尝试对不使用安全编码的对象进行解码时为我抛出了一个错误。经过多次试验和错误，这才是最终有效的方法，而没有触发iOS 12/13弃用警告：

// Archive the object
NSData* data = [NSKeyedArchiver archivedDataWithRootObject:theObject requiringSecureCoding:NO error:nil];

// Unarchive the object
NSKeyedUnarchiver* unarchiver = [[NSKeyedUnarchiver alloc] initForReadingFromData:data error:nil];
unarchiver.requiresSecureCoding = NO;
id theCopy = [unarchiver decodeTopLevelObjectForKey:NSKeyedArchiveRootObjectKey error:nil];

iOS 12.0使用不推荐使用的archiveRootObject：toFile的替代方法：

4 个答案: