NSURLSession取消任务

本文介绍了NSURLSession取消任务的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我使用以下配置创建新的NSURLSession

if（！self.session）{ NSURLSessionConfiguration * config = [NSURLSessionConfiguration backgroundSessionConfiguration：[self uniquieIdentifier]]; config.discretionary = NO; self.session = [NSURLSession sessionWithConfiguration：config delegate：self delegateQueue：[NSOperationQueue mainQueue]]; }

然后按下按钮我试图停止所有当前的下载任务。

[[[self session] delegateQueue] setSuspended：YES]; [[self session] invalidateAndCancel];不过我得到的响应委托方法didFinishDownloadingToURL，我很确定没有新的会话或下载任务是在这一点之后创建的。如何停止所有任务的发生？

解决方案

我不建议使用invalidateAndCancel方法导致队列及其标识符保持无效，无法重复使用，直到您重置整个设备。

NSURLSession类参考

我使用此代码取消所有待处理的任务。

- （void）cancelDownloadFiles { [self.session getTasksWithCompletionHandler： （NSArray * dataTasks，NSArray * uploadTasks，NSArray * downloadTasks）{ for（NSURLSessionTask * _task in downloadTasks） { [_task cancel]; id< FFDownloadFileProtocol> file = [self getFileDownloadInfoIndexWithTaskIdentifier：_task.taskIdentifier]; [file.downloadTask cancel]; //更改所有相关属性。 file.isDownloading = NO; file.taskIdentifier = -1; file.downloadProgress = 0.0; } }]; cancel = YES; }

I create new NSURLSession with following configs

if (!self.session) { NSURLSessionConfiguration *config = [NSURLSessionConfiguration backgroundSessionConfiguration:[self uniquieIdentifier]]; config.discretionary = NO; self.session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:[NSOperationQueue mainQueue]]; }

and on after pressing a button I am trying to stop all current download tasks.

[[[self session] delegateQueue] setSuspended:YES]; [[self session] invalidateAndCancel];

Nevertheless I get responses in delegate method didFinishDownloadingToURL, and I am pretty sure that no new sessions or download task are created after this point. How to stop all task from happening?

解决方案

I do not reccommend to use invalidateAndCancel method cause the queue and its identifier keeps invalidated and cannot be reused untill you reset the whole device.

NSURLSession class reference

I use this code to cancel all pending tasks.

- (void) cancelDownloadFiles { [self.session getTasksWithCompletionHandler:^(NSArray *dataTasks, NSArray *uploadTasks, NSArray *downloadTasks) { for (NSURLSessionTask *_task in downloadTasks) { [_task cancel]; id<FFDownloadFileProtocol> file = [self getFileDownloadInfoIndexWithTaskIdentifier:_task.taskIdentifier]; [file.downloadTask cancel]; // Change all related properties. file.isDownloading = NO; file.taskIdentifier = -1; file.downloadProgress = 0.0; } }]; cancel = YES; }