在我的应用程序中，当应用程序进入后台时，我尝试将一些数据上传到服务器。这是我正在使用的代码：
会议
self.session = [self backgroundSession];
这就是我的会话设置方式
- (NSURLSession *)backgroundSession
{
static NSURLSession *session = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration backgroundSessionConfiguration:@"com.uploadSession"];
configuration.HTTPMaximumConnectionsPerHost = 1;
session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
});
return session;
}
开始上传
- (void)applicationDidEnterBackground:(UIApplication *)application
{
[self uploadPossibleDrives];
}
上传
// Start uploading the remaing gps log in th right order:
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[queue setMaxConcurrentOperationCount:1];
for (int i = 0; i < arrayOfGPSLogChunks.count; i++)
{
// This will ensure the chunks are sent in the right order
// Add an operation as a block to a queue:
[queue addOperationWithBlock: ^ {
NSData *requestData;
NSMutableURLRequest *request;
if (i == 0)
{
NSLog(@"Initial drive upload %i",ID.integerValue);
requestData = [NSJSONSerialization dataWithJSONObject:historyToUpload options:NSJSONWritingPrettyPrinted error:nil];
request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:kInitialUploadDriveURL];
[request setHTTPMethod:@"POST"];
[request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
[request setValue:[NSString stringWithFormat:@"%d", [requestData length]] forHTTPHeaderField:@"Content-Length"];
}
else
{
NSLog(@"Chunk %i",i);
NSMutableDictionary *chunk = [[NSMutableDictionary alloc] init];
[chunk setObject:driveID forKey:@"driveID"];
[chunk setObject:[arrayOfGPSLogChunks objectAtIndex:i] forKey:@"gpsLog"];
requestData = [NSJSONSerialization dataWithJSONObject:chunk options:NSJSONWritingPrettyPrinted error:nil];
request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:kUploadDrivesChunkURL]];
[request setHTTPMethod:@"POST"];
[request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
[request setValue:[NSString stringWithFormat:@"%d", [requestData length]] forHTTPHeaderField:@"Content-Length"];
}
NSLog(@"_session: %@",self.session);
NSLog(@"request: %@",request);
NSLog(@"requestData: %lu",(unsigned long)requestData.length);
NSLog(@"uploadTask: %@",self.uploadTask);
self.uploadTask = [self.session uploadTaskWithRequest:request fromData:requestData];
[self.uploadTask resume];
if (i == arrayOfGPSLogChunks.count-1)
{
// All gps logs were uploaded so now we save its state as 'uploaded to server':
NSLog(@"Finished sending to server!");
[self setSentToServerForDriveID:ID];
}
}];
}
错误
现在这是我得到的错误：
我希望有人能帮助我。我已经调查了我所知道的一切，但似乎无法弄清楚出了什么问题。我也尝试在不使用块的情况下上传，但结果是一样的。
任何帮助将不胜感激！