#import "ViewController.h"
@interface ViewController ()<NSURLSessionDelegate,NSURLSessionTaskDelegate,NSURLSessionDataDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (weak, nonatomic) IBOutlet UIProgressView *progress;
@property (nonatomic,strong) NSURLSession * session;
@property (nonatomic,strong) NSURLSessionDataTask * dataTask;
@property (nonatomic,strong) NSMutableData * imageData;
@property (nonatomic,assign) long long length;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
}
-(NSURLSession *)session{
if (_session == nil) {
NSURLSessionConfiguration * config = [NSURLSessionConfiguration defaultSessionConfiguration];
self.session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:[NSOperationQueue mainQueue]];
}
return _session;
}
-(NSURLSessionDataTask *)dataTask{
if (_dataTask ==nil) {
NSURL * url = [NSURL URLWithString:@"http://img1.3lian.com/2015/a1/124/d/181.jpg"];
self.dataTask = [self.session dataTaskWithURL:url];
}
return _dataTask;
}
- (IBAction)suspendenButtonDidClicked:(UIButton *)sender {
if (self.dataTask.state == NSURLSessionTaskStateRunning) {
[self.dataTask suspend];
}
}
- (IBAction)resumeButtonDidClicked:(UIButton *)sender {
[self.dataTask resume];
}
- (IBAction)cancelButtonDidClicked:(UIButton *)sender {
if (_dataTask) {
if (self.dataTask.state == NSURLSessionTaskStateRunning||NSURLSessionTaskStateSuspended) {
[self.dataTask cancel];
self.dataTask=nil;
self.session = nil;
[self.progress setProgress:0 animated:NO];
}
}
}
//获取服务器返回的响应信息
-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler{
//转换
NSHTTPURLResponse * httpResponse = (NSHTTPURLResponse *)response;
NSLog(@"%@",[httpResponse allHeaderFields]);
//获取资源大小
self.length = httpResponse.expectedContentLength;
NSLog(@"responce");
if (_length!=-1) {
//继续下载或上传
self.imageData = [NSMutableData dataWithCapacity:(NSUInteger)_length];
completionHandler(NSURLSessionResponseAllow);
}else{
completionHandler(NSURLSessionResponseCancel);
[self.dataTask cancel];
self.dataTask = nil;
}
}
//一个数据包过来了
-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(nonnull NSData *)data{
NSLog(@"receive data");
//将当前的数据添加到imageData中
[self.imageData appendData:data];
float rate = data.length/(_length*1.0);
[self.progress setProgress:(_progress.progress +rate) animated:NO];
}
//下载完毕
-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{
NSLog(@"complete");
if (error) {
NSLog(@"error");
}else{
UIImage * img = [UIImage imageWithData:_imageData];
self.imageView.image = img;
}
self.session = nil;
self.dataTask = nil;
}
@end