我创建了一个名为NSOperation的DownloadQueue子类。我将所有对象一个一个地添加到NSOperationQueue，即appDelegate.queueDownload。
问题是，执行DownloadOperation的对象时，一旦执行download的DownloadOperation方法，我的DownloadOperation的对象就会从队列中删除。
但是我必须将其保留在内存中，因为当我在downloadFromPath中进行[使用DownloadOperation.m]异步调用并且服务器响应文件数据时，那时DownloadOperation对象被释放并且liveOperationSucceeded从未被调用。
可能是我认为这个问题有点复杂，因此在举报之前请仔细阅读两次!对我来说很重要。感谢您的理解。
// Adding to queue
DownloadOperation *operation = [[DownloadOperation alloc] init];
operation.delegate = self;
[operation operationWithFileOrFolderID:dictDocument[@"id"] withParentPath:self.strParentPath download:NO withFileName:dictDocument[@"name"] withDictionary:dictDocument];
[operation download];
[operation setQueuePriority:NSOperationQueuePriorityVeryHigh];
[appDelegate.queueDownload addOperation:operation];
DownloadOperation.m(是
NSOperation的子类)@implementation DownloadOperation
-(void)main
{
[self download];
}
- (void)operationWithFileOrFolderID: (NSString *)strID withParentPath: (NSString *)strParentPath download: (BOOL)isDownload withFileName: (NSString *)strFileName withDictionary: (NSMutableDictionary *)dictInfoLocal
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
self.documentsDirectory = paths[0];
self.strFileName = strFileName;
self.strID = strID;
self.strParentPath = strParentPath;
self.dictInfo = dictInfoLocal;
if (self)
{
}
}
- (void)download
{
self.liveClient = [[LiveConnectClient alloc] initWithClientId:CLIENT_ID delegate:self];
[self.liveClient downloadFromPath:[self.strID stringByAppendingString:@"/content"] delegate:self];
NSLog(@"DownloadFilesVC : Downloading : %@",self.strFileName);
}
- (void) liveOperationSucceeded:(LiveOperation *)operation
{
}
- (void) liveOperationFailed:(NSError *)error
operation:(LiveOperation *)operation
{
}
- (void) liveDownloadOperationProgressed:(LiveOperationProgress *)progress data:(NSData *)receivedData operation:(LiveDownloadOperation *)operation
{
}
@end
最佳答案
您在操作内部有一个异步操作。
操作队列完全按照预期的方式运行，并且在DownloadOperation方法完成后会弹出完成的download。不在乎该操作是否具有回调。
您需要保留DownloadOperation操作的所有权，方法是将其添加到强引用的集合(例如NSArray或NSSet)中，并在LiveConnectClient完成时将其丢弃。您可能希望在DownloadOperation中添加一个BOOL属性来表示。@property BOOL imReallyReallyFinishedAndCanBeDiscardedOK;
编辑
该API是基于异步/委托的。一种简单的方法是遍历文件夹内容并计算返回响应。收到与请求数量匹配的响应数量后，便知道您已完成。
作为一个非常简化的版本，它不关心递归或错误。
@interface DownloadManager : NSObject
@property NSArray *fileRefList;
@property NSUInteger count;
@property (strong) void (^completionBlock)();
@end
@implementation DownloadManager
-(void)downloadAllTheFiles {
self.count = 0;
for(NSString *strID in self.fileRefList) {
LiveConnectClient *liveClient = [[LiveConnectClient alloc] initWithClientId:CLIENT_ID delegate:self];
[liveClient downloadFromPath:[strID stringByAppendingString:@"/content"] delegate:self];
}
}
- (void) liveOperationSucceeded:(LiveOperation *)operation
{
self.count++;
[self haveIFinished];
}
- (void) liveOperationFailed:(NSError *)error
operation:(LiveOperation *)operation
{
self.count++;
[self haveIFinished];
}
-(void)haveIFinished {
if (self.count == self.fileRefList.count) {
if (self.completionBlock) {
self.completionBlock();
}
}
}
让API为您执行队列操作和后台操作。完成后触发任意块。