會話完成所有任務后，如何使用AFNetworking 3.0在后台下載大文件並顯示本地通知

Question

我正在嘗試使用AFNetworking 3.0在我的應用程序中下載大型視頻文件。 我找不到有關如何使用AFNetworking在后台下載文件的任何特定文檔。

我知道AFNetworking使用AFURLSessionManager和AFHTTPSessionManager本身實現了NSURLSession的所有委托。

到目前為止，我要做的是創建一個backgroundSessionConfugaration並開始使用該文件下載文件。

self.manager = [[AFHTTPSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:bgDownloadSessionIdentifier]];

[self.manager downloadTaskWithRequest:request progress:nil destination:nil completionHandler:nil];

開始下載時，我將應用程序置於后台。 到目前為止，我發現應用程序在后台運行直到20分鍾，並且下載成功。 但是appDelegate中的 application：handleEventsForBackgroundURLSession沒有被調用，所以我的setDidFinishEventsForBackgroundURLSessionBlock也沒有被調用。

我只想在調用setDidFinishEventsForBackgroundURLSessionBlock時顯示通知。

當我初始化經理使用此。 （而不是backgroundSessionConfiguration ）

self.manager = [AFHTTPSessionManager manager];

Still應用程序能夠在后台運行20分鍾后下載整個文件。

我的問題是為什么應用程序要運行20分鍾並完成下載。 理想情況下，iOS應在10分鍾后終止該應用程序。 還有為什么會話完成后未調用application：handleEventsForBackgroundURLSession的原因。

我已經提到了AFNetworking 2.0和后台傳輸 ，但是它似乎對我不起作用。

功能的后台模式為“打開”或“關閉”不會影響我的應用程序。

請幫助我或建議我在這里做錯了什么。

我在這里上傳了示例代碼。 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;
 }

Answer 1

有時不會調用此委托方法，

• 如果任務完成時應用程序已在運行。
• 應用程序通過主頁按鈕終止。
• 如果您無法使用相同的標識符啟動后台NSURLSession。

注意 ：這在模擬器上的行為有所不同，因此請在真實設備上進行檢查。

Answer 2

為什么只在downloadInBackgroundWithURL：downloadProgress：fucntion中沒有將本地通知塊替換為成功塊？ 實際上不會調用AppDelegate中的方法。 您需要注冊您的通知

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.

    if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]){
         [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];
    }

    return YES;
}

對於本地通知，請添加觸發日期和時區：

    UILocalNotification* localNotification = [[UILocalNotification alloc] init];
    localNotification.alertBody = @"Download Complete!";
    localNotification.alertAction = @"Background Transfer Download!";
    [localNotification setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
    [localNotification setTimeZone:[NSTimeZone  defaultTimeZone]];
    //On sound
    localNotification.soundName = UILocalNotificationDefaultSoundName;

    //increase the badge number of application plus 1
    localNotification.applicationIconBadgeNumber = [[UIApplication sharedApplication] applicationIconBadgeNumber] + 1;

    [[UIApplication sharedApplication] presentLocalNotificationNow:localNotification];

現在可以了。 干杯。