我正在尝试使用 AFNetworking 3.0 在我的应用程序中下载大型视频文件。我找不到任何关于如何使用 AFNetworking 在后台下载文件的具体文档。
我知道 AFNetworking 使用AFURLSessionManager和AFHTTPSessionManager，它们本身实现了NSURLSession的所有代表。
到目前为止我所做的是，创建了一个backgroundSessionConfugaration并开始使用它下载一个文件。
self.manager = [[AFHTTPSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:bgDownloadSessionIdentifier]];
[self.manager downloadTaskWithRequest:request progress:nil destination:nil completionHandler:nil];
下载开始时，我将应用程序置于后台。到目前为止，我发现应用程序在后台运行了 20 分钟，并且下载成功。但是appDelegate 中的application:handleEventsForBackgroundURLSession没有被调用，所以我的setDidFinishEventsForBackgroundURLSessionBlock也没有被调用。
我只想在调用setDidFinishEventsForBackgroundURLSessionBlock时显示通知。
当我使用它初始化管理器时。（而不是backgroundSessionConfiguration）
self.manager = [AFHTTPSessionManager manager];
仍然应用程序能够在后台 20 分钟后下载整个文件。
我的问题是为什么应用程序运行到 20 分钟并完成下载。理想情况下，iOS 应该在 10 分钟后终止应用程序。还有为什么application:handleEventsForBackgroundURLSession在会话完成后没有被调用。
我已经提到了这个AFNetworking 2.0 and background transfer，但它似乎对我不起作用。
功能中的后台模式打开或关闭不会影响我的应用程序中的任何内容。
请帮助我或建议我在这里做错了什么。
我在这里上传了示例代码。 https://www.dropbox.com/s/umwicuta2qzd3k1/RSNetworkKitExample.zip?dl=0
AppDelegate.m
-(void)application:(UIApplication *)application handleEventsForBackgroundURLSession:(NSString *)identifier completionHandler:(void (^)())completionHandler {
NSLog(@"===== background session completed in AppDelegate ===== ");
if([identifier isEqualToString:bgDownloadSessionIdentifier]){
[RSDownloadManager sharedManager].backgroundSessionCompletionHandler = completionHandler;
}
}
==================================================== ==
ViewController.m
- (IBAction)downloadVideoInBackground:(id)sender {
NSString *videoURL = @"http://videos1.djmazadownload.com/mobile/mobile_videos/Tum%20Saath%20Ho%20(Tamasha)%20(DJMaza.Info).mp4";
[RSDownloadManager sharedManager].backgroundSessionCompletionHandler = ^{
NSLog(@"===== background session completed in ViewController ===== ");
UILocalNotification* localNotification = [[UILocalNotification alloc] init];
localNotification.alertBody = @"Download Complete!";
localNotification.alertAction = @"Background Transfer Download!";
//On sound
localNotification.soundName = UILocalNotificationDefaultSoundName;
//increase the badge number of application plus 1
localNotification.applicationIconBadgeNumber = [[UIApplication sharedApplication] applicationIconBadgeNumber] + 1;
[[UIApplication sharedApplication] presentLocalNotificationNow:localNotification];
};
[[RSDownloadManager sharedManager] downloadInBackgroundWithURL:videoURL downloadProgress:^(NSNumber *progress) {
NSLog(@"Video download progress %.2f", [progress floatValue]);
} success:^(NSURLResponse *response, NSURL *filePath) {
NSLog(@"Video download completed at Path %@", filePath);
} andFailure:^(NSError *error) {
NSLog(@"Error in video download %@", error.description);
}];
}
==================================================== ==
RSDownloadManager.h
#import <Foundation/Foundation.h>
#import "AFHTTPSessionManager.h"
static NSString *bgDownloadSessionIdentifier = @"com.RSNetworkKit.bgDownloadSessionIdentifier";
@interface RSDownloadManager : NSObject
@property (nonatomic, strong) AFHTTPSessionManager *manager;
@property (nonatomic, copy) void (^backgroundSessionCompletionHandler)(void);
+(instancetype)sharedManager;
-(NSURLSessionDownloadTask *)downloadInBackgroundWithURL:(NSString *)urlString downloadProgress:(void (^)(NSNumber *progress))progressBlock success:(void (^)(NSURLResponse *response, NSURL *filePath))completionBlock andFailure:(void (^)(NSError *error))failureBlock;
@end
==================================================== ==
RSDownloadManager.m
@implementation RSDownloadManager
#pragma mark - Singleton instance
+(instancetype)sharedManager
{
static RSDownloadManager *_downloadManager = nil;
static dispatch_once_t token;
dispatch_once(&token, ^{
if (!_downloadManager) {
_downloadManager = [[self alloc] init];
}
});
return _downloadManager;
}
#pragma mark - Init with Session Configuration
-(void)initWithSessionConfiguration:(NSURLSessionConfiguration *)configuration {
self.manager = [[AFHTTPSessionManager alloc] initWithSessionConfiguration:configuration];
//self.manager = [AFHTTPSessionManager manager];
}
#pragma mark- Handle background session completion
- (void)configureBackgroundSessionCompletion {
typeof(self) __weak weakSelf = self;
[self.manager setDidFinishEventsForBackgroundURLSessionBlock:^(NSURLSession *session) {
if (weakSelf.backgroundSessionCompletionHandler) {
weakSelf.backgroundSessionCompletionHandler();
weakSelf.backgroundSessionCompletionHandler = nil;
}
}];
}
#pragma mark- download in background request Method
-(NSURLSessionDownloadTask *)downloadInBackgroundWithURL:(NSString *)urlString downloadProgress:(void (^)(NSNumber *))progressBlock success:(void (^)(NSURLResponse *, NSURL *))completionBlock andFailure:(void (^)(NSError *))failureBlock {
/* initialise session manager with background configuration */
if(!self.manager){
[self initWithSessionConfiguration:[NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:bgDownloadSessionIdentifier]];
}
[self configureBackgroundSessionCompletion];
/* Create a request from the url */
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];
NSURLSessionDownloadTask *downloadTask = [self.manager downloadTaskWithRequest:request progress:^(NSProgress * _Nonnull downloadProgress) {
if(progressBlock) {
progressBlock ([NSNumber numberWithDouble:downloadProgress.fractionCompleted]);
}
} destination:^NSURL * _Nonnull(NSURL * _Nonnull targetPath, NSURLResponse * _Nonnull response) {
NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
return [documentsDirectoryURL URLByAppendingPathComponent:[response suggestedFilename]];
} completionHandler:^(NSURLResponse * _Nonnull response, NSURL * _Nullable filePath, NSError * _Nullable error) {
if(error) {
if(failureBlock) {
failureBlock (error);
}
}
else {
if(completionBlock) {
completionBlock (response, filePath);
}
}
}];
[downloadTask resume];
return downloadTask;
}