通过AirDrop发送NSArray

Question

我有一台NSMutableArray self.certificates

该数组由保存的字符串和核心数据组成。我想通过AirDrop发送这个。我已经查看了serialization，我正试着把它和下面的内容一起发送

- (void)send{

NSData *jsonData2 = [NSJSONSerialization dataWithJSONObject:self.certificates options:NSJSONWritingPrettyPrinted error:nil];

NSString *jsonString = [[NSString alloc] initWithData:jsonData2 encoding:NSUTF8StringEncoding];
NSLog(@"Electrical Certificates List:\n%@", jsonString);


UIActivityViewController *activityCtr = [[UIActivityViewController alloc] initWithActivityItems:@[jsonString]
                                                                          applicationActivities:nil];

NSMutableArray *excludedActivities = [self iOSActivities].mutableCopy;
[excludedActivities addObject:UIActivityTypeAddToReadingList];
[excludedActivities addObject:UIActivityTypePostToFlickr];
[excludedActivities addObject:UIActivityTypePostToTencentWeibo];
[excludedActivities addObject:UIActivityTypePostToVimeo];
[activityCtr setExcludedActivityTypes:excludedActivities];

[self presentViewController:activityCtr
                   animated:YES
                 completion:nil];
}

这会给出以下错误

'NSInvalidArgumentException', reason: 'Invalid type in JSON write (Certificate)'

我已经将数据转换为字符串，所以不确定这里缺少什么

我研究了NSInvalidArgumentException, reason: 'Invalid type in JSON write (__NSDate)'和How to send NSArray to web service

Answer 1

在将数组转换为数据之前，JSONSerialization会抛出异常。

要共享自定义数据类型，您需要在模型对象上实现NSCoding和UIActivityItemSource：

@interface CertificateGroup : NSObject <NSCoding, UIActivityItemSource>

@property(copy, nonatomic) NSArray *certificates;

@end

@implementation CertificateGroup

- (void)encodeWithCoder:(NSCoder *)aCoder {
    // Save all your custom properties
    [aCoder encodeObject:self.certificates forKey:@"certificates"]l
}

- (id)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    if (self) {
        // Read back properties
        self.certificates = [aDecoder decodeObjectForKey:@"certificates"];
    }
    return self;
}

- (id)activityViewControllerPlaceholderItem:(UIActivityViewController *)activityViewController
{
    //Let the activity view controller know NSData is being sent by passing this placeholder.
    return [NSData data];
}

- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(NSString *)activityType
{
    //Serialize this object for sending. NSCoding protocol must be implemented for the serialization to occur.
    return [NSKeyedArchiver archivedDataWithRootObject:self];
}

- (NSString *)activityViewController:(UIActivityViewController *)activityViewController dataTypeIdentifierForActivityType:(NSString *)activityType {
    return @"com.mycompany.myapp.certificates";
}

@end

然后，当您创建activity视图控制器时：

CertificatesGroup *group = [CertificatesGroup new];
group.certificates = self.certificates;
UIActivityViewController *activityCtr = [[UIActivityViewController alloc] initWithActivityItems:@[group]
                                                                          applicationActivities:nil];
...

你的应用代理应该实现-application:openURL:sourceApplication:annotation:并解码传入的证书。

- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation {
     NSData *groupData = [NSData dataWithContentsOfURL:url];
     CertificatesGroup *group = [NSKeyedUnarchiver unarchiveObjectWithData:groupData];
     NSLog(@"%@", group.certificates);
     return YES;
}

有关更多信息，请参阅苹果的AirDropSample项目，特别是APLProfile.h/.m、APLProfileViewController.h/.m和AppDelegate.m。