相册添加下载照片

AFHTTPSessionManager * session = [AFHTTPSessionManager manager];

    session.requestSerializer= [AFHTTPRequestSerializer serializer];

    session.responseSerializer= [AFHTTPResponseSerializer serializer];

    NSURLRequest * request = [NSURLRequest requestWithURL:[NSURL URLWithString:imageURL]];

    NSURLSessionDownloadTask*downloadTask =  [sessiondownloadTaskWithRequest:requestprogress:^(NSProgress*_NonnulldownloadProgress) {        

CGFloatpercent = (CGFloat)downloadProgress.completedUnitCount/downloadProgress.totalUnitCount;

}destination:^NSURL*_Nonnull(NSURL*_NonnulltargetPath,NSURLResponse*_Nonnullresponse) {

        NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];

        return[documentsDirectoryURLURLByAppendingPathComponent:[responsesuggestedFilename]];

    }completionHandler:^(NSURLResponse*_Nonnullresponse,NSURL*_NullablefilePath,NSError*_Nullableerror) {

NSFileManager * fileManager = [NSFileManager defaultManager];

        BOOLisFile = [fileManagerfileExistsAtPath:[filePathpath]];

        if(isFile) {

[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {

                    if(status ==PHAuthorizationStatusAuthorized) {

                        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{

                            [PHAssetChangeRequest creationRequestForAssetFromImage:image];

                        }completionHandler:^(BOOLsuccess,NSError*_Nullableerror) {

                            if(success) {

                            }else{

                            }

                        }];

                    }else{

                    }

                }];

            });

        }