在我的应用程序中，我有几个持久存储，用户可以删除和添加存储。我最近将 iCloud 添加到项目中，现在我需要知道哪些商店在启动时可用，以便我可以列出它们。以前这是由我在创建和删除商店时管理的数组处理的。但是现在可以创建或删除存储或单独的设备，我希望在我的 ubiquity 容器中获得所有可用的持久存储。这可能吗？
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155 次
2 回答
1
这是我用来查找新文件或已删除文件的代码。发表您的任何问题，我会尽力回复。
/*! Creates and starts a metadata query for iCloud files
*/
- (void)createFileQuery {
[_query stopQuery];
if ([[CloudManager sharedManager] isCloudEnabled]) {
if (_query) {
[_query startQuery];
}
else {
_query = [[NSMetadataQuery alloc] init];
[_query setSearchScopes:[NSArray arrayWithObjects:NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryUbiquitousDataScope, nil]];
NSString *str = @"*";
[_query setPredicate:[NSPredicate predicateWithFormat:@"%K LIKE %@", NSMetadataItemFSNameKey, str]];
NSNotificationCenter* notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter addObserver:self selector:@selector(fileListReceived) name:NSMetadataQueryDidFinishGatheringNotification object:_query];
[notificationCenter addObserver:self selector:@selector(fileListReceived) name:NSMetadataQueryDidUpdateNotification object:_query];
[_query startQuery];
}
}
}
/*! Gets called by the metadata query any time files change
*/
- (void)fileListReceived {
//LOG(@"fileListReceived called.");
bool found = NO;
if ([self getNewiCloudDocs]) {
//LOG(@" New iCloud documents found!");
found = YES;
}
if ([self getDeletediCloudDocs]) {
//LOG(@" Deleted iCloud documents found!");
found = YES;
}
// Just check the local files again...
if (found)
[self updateList];
return;
}
/*! Gets the list of files in the iCloud directory and compares against files we have locally
and then creates new ones if required. WARNING: files appear in iCloud before they appear
locally when we are creating new documents so we must set a flag so we know to ignore any
new files that appear if we are busy creating a new document already. Only applies if we
have initiated creating a new document on this device!
@return Returns true if any have been found
*/
- (bool)getNewiCloudDocs {
//FLOG(@"getNewiCloudDocs called");
bool found = NO;
NSURL *iCloudDirectory = [[CloudManager sharedManager] iCloudCoreDataURL];
//FLOG(@" iCloudDirectory is %@", iCloudDirectory);
// Get the top level directory names are these will represent all the iCloud documents
NSArray* cloudDocuments = [[NSFileManager defaultManager] contentsOfDirectoryAtURL:iCloudDirectory includingPropertiesForKeys:nil options:0 error:nil];
//Now get an array of the local document names including any UUID because we want then to be unique
NSMutableArray *localFileIDs = [[NSMutableArray alloc] init];
for (NSURL *doc in _localDocuments) {
[localFileIDs addObject:[doc lastPathComponent]];
}
// Check if there are any we don't already have
//FLOG(@" iCloud Documents are:");
for (NSURL* document in cloudDocuments) {
//FLOG(@" %@", [document lastPathComponent]);
NSString *name = [document lastPathComponent];
if (![localFileIDs containsObject:name]) {
//FLOG(@" new file found: %@", name);
found = YES;
[self createLocalCopyOfICloudFile: name];
}
}
return found;
}
/*! Looks for files we have that are not in iCloud and are local.
These have probably been deleted by some other device so remove them.
@return Returns true if any have been found
*/
- (bool)getDeletediCloudDocs {
//FLOG(@"getDeletediCloudDocs called");
bool found = NO;
NSURL *iCloudDirectory = [[CloudManager sharedManager] iCloudCoreDataURL];
//Now get an array of the local document names including any UUID because we want then to be unique
NSMutableArray *localFileIDs = [[NSMutableArray alloc] init];
NSMutableArray *cloudFileIDs = [[NSMutableArray alloc] init];
for (NSURL *doc in _localDocuments) {
[localFileIDs addObject:[doc lastPathComponent]];
}
// Get the top level directory names are these will represent all the iCloud documents
NSArray* cloudDocuments = [[NSFileManager defaultManager] contentsOfDirectoryAtURL:iCloudDirectory includingPropertiesForKeys:nil options:0 error:nil];
if ([cloudDocuments count]) {
//FLOG(@" %d documents found in iCloud", [cloudDocuments count]);
//FLOG(@" docs are: %@", cloudDocuments);
for (NSURL* doc in cloudDocuments) {
[cloudFileIDs addObject:[doc lastPathComponent]];
}
// Check if there are documents that we have that are not in iCloud
//FLOG(@" Deleted iCloud Documents are:");
for (NSURL* document in _localDocuments) {
NSString *name = [document lastPathComponent];
if (![cloudFileIDs containsObject:name]) {
FLOG(@" REMOVED iCloud file detected: %@", name);
found = YES;
[self removeLocalCopyOfiCloudFile: name];
}
}
} else {
FLOG(@" no documents found in iCloud");
FLOG(@" removing all local documents");
for (NSURL* document in _localDocuments) {
NSString *name = [document lastPathComponent];
//FLOG(@" removing local file %@", name);
found = YES;
[self removeLocalCopyOfiCloudFile: name];
}
}
return found;
}
- (void)createLocalCopyOfICloudFile:(NSString *)fileName {
if (!_creatingDocument) {
NSURL* fileURL = [[[CloudManager sharedManager] documentsDirectoryURL] URLByAppendingPathComponent:fileName];
[self.appDelegate createLocalCopyOfCloudFile:fileURL];
} else {
LOG(@"Busy creating document so don't do anything!");
}
}
- (void)removeLocalFile:(NSString *)fileName {
LOG(@"");
FLOG(@" REMOVING local copy of file: %@", fileName);
NSURL* fileURL = [[[CloudManager sharedManager] documentsDirectoryURL] URLByAppendingPathComponent:fileName];
[self deleteDocumentAtURL:fileURL];
LOG(@"");
}
- (void)removeLocalCopyOfiCloudFile:(NSString *)fileName {
LOG(@"");
if (!_deletingDocument) {
FLOG(@" REMOVING local copy of DELETED iCloud file: %@", fileName);
NSURL* fileURL = [[[CloudManager sharedManager] documentsDirectoryURL] URLByAppendingPathComponent:fileName];
[self deleteLocalCopyOfiCloudDocumentAtURL:fileURL];
LOG(@"");
} else {
LOG(@"Busy deleting document so don't do anything!");
}
}
于 2013-11-27T09:59:01.810 回答
0
对 ubiquity 容器进行元数据扫描，并获取应用程序 ubiquity 容器 /CoreData 目录中所有目录的列表。这些目录应与通过 iCloud 同步的所有商店的 NSPersistentStoreUbiquityNameKey 对应。我似乎记得 Apple 的 wwdc2013 207 视频解释了这就是 Core Data/iCloud 集成的工作原理。
我使用一个包含用户输入的文件名+' UUID '+uuid 的字符串作为 NSPersistentStoreUbiquityNameKey，以便在另一台设备上向用户显示相同的文件名。
我扫描这样的“新”文件是否存在，当我检测到一个时，我会自动构建存储的本地副本，同样，当我检测到文件已被删除时，我会自动删除本地存储。
请注意，我还存储有关文件的本地元数据，以便在打开它时可以确定将正确的选项传递给persistentStoreCoordinator。
如果您有兴趣，我可以发布我用来进行扫描的代码。
注意：请记住，存储本身不存储在 iCloud 中，只有事务日志存储，因此您需要构建本地存储并传入正确的 NSPersistentStoreUbiquityNameKey，然后 Core Data 将从 iCloud 导入事务日志。
于 2013-11-25T20:26:07.280 回答