本文介绍了NSURLSession:调用ancelByProducingResumeData后无法获取简历数据的处理方法,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
我想在用户取消下载或出现问题后继续下载。但是当我调用cancelByProducingResumeData
方法时,resumeData
是nil
。所以,我无法继续下载。我相信下载链接可以恢复,因为我们的PC客户端可以恢复下载此链接。
这是我的代码。这里是the full project。
#import "ViewController.h"
@interface ViewController ()
{
NSURLSession *_session;
}
@property (weak, nonatomic) IBOutlet UIProgressView *progressView;
@property NSURLSessionDownloadTask *netTask;
@property NSData *resumeData;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
if (_session == nil) {
NSURLSessionConfiguration *confi = [NSURLSessionConfiguration defaultSessionConfiguration];
_session = [NSURLSession sessionWithConfiguration:confi delegate:self delegateQueue:[NSOperationQueue mainQueue]];
}
}
- (IBAction)startAction:(id)sender {
[self start];
}
- (IBAction)stopActon:(id)sender {
[self stop];
}
- (void)stop {
__weak typeof(self) vc = self;
[self.netTask cancelByProducingResumeData:^(NSData * _Nullable resumeData) {
vc.resumeData = resumeData;
vc.netTask = nil;
}];
}
- (void)start {
if (self.resumeData != nil) {
self.netTask = [_session downloadTaskWithResumeData:self.resumeData];
} else {
NSURL *downlaodURL = [NSURL URLWithString:@"http://sdl24.yunpan.cn/share.php?method=Share.download&cqid=37ef0df7c8155bacf55c237bd433ddd8&dt=24.02b6cbb4148de503fe35ddab08dac35b&e=1459317290&fhash=41181b28ff97806ef8469842b4a5eabc330a0c60&fname=feistudy%2B%2B%25E8%25AF%25AD%25E8%25A8%2580%25E5%25AD%25A6%25E4%25B9%25A0%25E6%2596%25B9%25E6%25B3%2595%25E8%25AE%25BA%25E8%25BF%25B0&fsize=87624815&nid=14471440239484082&st=e08142ab7c935cdd15ecc8851c82e819&xqid=22309244"];
self.netTask = [_session downloadTaskWithURL:downlaodURL];
}
[self.netTask resume];
}
- (NSString*)filePath
{
NSString *doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *path = [doc stringByAppendingPathComponent:@"p.rmvb"];
return path;
}
#pragma mark - NSURLSessionDownloadDelegate
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask
didFinishDownloadingToURL:(NSURL *)location
{
dispatch_async(dispatch_get_main_queue(), ^{
NSFileManager *manager = [NSFileManager defaultManager];
[manager moveItemAtPath:location.path toPath:[self filePath] error:nil];
NSLog(@"locaton.path:%@", location.path);
NSLog(@"filePaht:%@",[self filePath]);
});
}
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask
didWriteData:(int64_t)bytesWritten
totalBytesWritten:(int64_t)totalBytesWritten
totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite
{
dispatch_async(dispatch_get_main_queue(), ^{
double progress = totalBytesWritten/(double)totalBytesExpectedToWrite;
NSLog(@"progress:%f",progress);
self.progressView.progress = progress;
});
}
#pragma mark - NSURLSessionTaskDelegate
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task
didCompleteWithError:(nullable NSError *)error
{
if (error) {
NSData *resumeData = error.userInfo[NSURLSessionDownloadTaskResumeData];
self.resumeData = resumeData;
}
}
@end
推荐答案
对于何时可以获取简历数据,有一长串要求。除其他事项外:
- 响应必须包含ETag或上次修改的标头。
- 我认为响应还必须包含Accept-Ranges:Bytes头
- 临时文件必须仍然存在(磁盘空间不能太少)。
- 必须是HTTP或HTTPS请求。
- Last-Modify或ETag标头必须指示文件自上次请求以来未更改过。
我可能忘记了其他要求,例如HTTP/1.1。
这篇关于NSURLSession:调用ancelByProducingResumeData后无法获取简历数据的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持编程学习网!
本站部分内容来源互联网,如果有图片或者内容侵犯您的权益请联系我们删除!