@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIProgressView *progressView;
/* 下载文件的工具 **/
@property (nonatomic, strong) NSURLSessionDownloadTask *task;
@property (nonatomic, strong) NSData *resumeData;
@property (nonatomic, strong) NSURLSession *session;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
}
#pragma mark - set/get 方法
- (NSURLSession*)session {
if(_session==nil) {
NSURLSessionConfiguration * config = [NSURLSessionConfiguration defaultSessionConfiguration];
_session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:[NSOperationQueue mainQueue]];
}
return _session;
}
/*开始下载的方法**/
- (IBAction)downLoad:(id)sender {
// 1.创建一个下载任务
NSURL *url = [NSURL URLWithString:@"http://weixue.steptowin.com:8000/data/img/20160411/veuyytthy4b2_320_200.jpg"];
self.task = [self.session downloadTaskWithURL:url];
// 2.开始任务
[self.taskresume];
}
/*暂停的点击方法 **/
- (IBAction)pause:(id)sender {
__weak typeof(self) vc = self;
[self.task cancelByProducingResumeData:^(NSData *resumeData) {
// resumeData : 包含了继续下载的开始位置\下载的url
vc.resumeData= resumeData;
vc.task=nil;
}];
}
/* 恢复的点击方法 **/
- (IBAction)resume:(id)sender {
// 传入上次暂停下载返回的数据，就可以恢复下载
self.task = [self.session downloadTaskWithResumeData:self.resumeData];
// 开始任务
[self.taskresume];
// 清空
self.resumeData = nil;
}
#pragma mark - NSURLSessionDownloadDelegate
/*下载完成的回调**/
- (void)URLSession:(NSURLSession*)session
downloadTask:(NSURLSessionDownloadTask*)downloadTask
didFinishDownloadingToURL:(NSURL*)location {
NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
// response.suggestedFilename ： 建议使用的文件名，一般跟服务器端的文件名一致
NSString*file = [cachesstringByAppendingPathComponent:downloadTask.response.suggestedFilename];
// 将临时文件剪切或者复制Caches文件夹
NSFileManager *mgr = [NSFileManager defaultManager];
// AtPath : 剪切前的文件路径
// ToPath : 剪切后的文件路径
[mgrmoveItemAtPath:location.pathtoPath:fileerror:nil];
}
/* 下载进度的回调 **/
- (void)URLSession:(NSURLSession*)session
downloadTask:(NSURLSessionDownloadTask*)downloadTask
didWriteData:(int64_t)bytesWritten
totalBytesWritten:(int64_t)totalBytesWritten
totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
NSLog(@"获得下载进度--%@", [NSThreadcurrentThread]);
// 获得下载进度
self.progressView.progress= (double)totalBytesWritten / totalBytesExpectedToWrite;
}
/* 恢复下载的回调，从哪里开始下载**/
- (void)URLSession:(NSURLSession*)session
downloadTask:(NSURLSessionDownloadTask*)downloadTask
didResumeAtOffset:(int64_t)fileOffset
expectedTotalBytes:(int64_t)expectedTotalBytes {
NSLog(@"fileOffset = %lld",fileOffset);
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
