iOS学习-10下载(4) NSURLSession 会话 篇

//
//  ViewController.m
//  NSURLSession会话
//
//  Copyright © 2016年 asamu. All rights reserved.
//

#import "ViewController.h"
@interface ViewController ()<NSURLSessionDownloadDelegate>
{
    NSURLSessionDownloadTask *_downloadTask;
}

@property (weak, nonatomic) IBOutlet UITextField *textField;
@property (weak, nonatomic) IBOutlet UIProgressView *progressView;

@property (weak, nonatomic) IBOutlet UILabel *label;
@property (weak, nonatomic) IBOutlet UIButton *downBtn;

@end

@implementation ViewController
#pragma mark -- UI方法
- (void)viewDidLoad {
    [super viewDidLoad];
    _progressView.progress = 0;
}
#pragma mark 按钮点击事件
- (IBAction)download:(id)sender {

    NSString *filename = _textField.text;
    NSString *urlStr = [NSString stringWithFormat:@"http://mr7.doubanio.com/832d52e9c3df5c13afd7243a770c094f/0/fm/song/p294_128k.mp3",filename];
    NSURL *url = [NSURL URLWithString:urlStr];
    //创建请求
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    //创建会话
      //默认会话
    NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
    //请求超过时间
    sessionConfiguration.timeoutIntervalForRequest = 5.0f;
    //是否允许使用蜂窝
    sessionConfiguration.allowsCellularAccess = true;
    //创建会话
    NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfiguration delegate:self delegateQueue:nil];
    _downloadTask = [session downloadTaskWithRequest:request];
    [_downloadTask resume];
}

- (IBAction)cancel:(id)sender {
    [_downloadTask cancel];
    _label.text = @"Cancel";
}

- (IBAction)suspend:(id)sender {
    [_downloadTask suspend];
    _label.text  =@"Suspend";
}
- (IBAction)resume:(id)sender {
    [_downloadTask resume];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}
#pragma mark - 设置界面状态
-(void)setUIStatus:(int64_t)totalBytesWritten expectedTowrite:(int64_t)totalBytesExpectedWritten{
    //更新 UI 放到主线程
    dispatch_async(dispatch_get_main_queue(), ^{
    //设置进度条
        _progressView.progress = (float)totalBytesWritten / totalBytesExpectedWritten;
    
        if (totalBytesWritten == totalBytesExpectedWritten) {
        
            _label.text = @"Finish download";
            //关网
            [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
            _downBtn.enabled = YES;
    
        }else{
    
            _label.text = @"Downing...";
            [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
    }
    });
}
#pragma mark - 下载任务代理
#pragma mark 下载中(会多次调用，可以记录下载进度)
-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite{
    [self setUIStatus:totalBytesWritten expectedTowrite:totalBytesExpectedToWrite];
}
#pragma mark 下载完成
-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{
    NSError *error;
    //注释见上篇，懒得写。。。
    NSString *cachePath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)lastObject];
    NSString *savePath = [cachePath stringByAppendingPathComponent:_textField.text];
    NSLog(@"%@",savePath);
    
    NSURL *url = [NSURL fileURLWithPath:savePath];
    
    [[NSFileManager defaultManager]moveItemAtURL:location toURL:url error:&error];
    if (error) {
        NSLog(@"%@",error.localizedDescription);
    }
}
#pragma mark 任务完成，不管是否下载成功
-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{
    if (error) {
    NSLog(@"%@",error.localizedDescription);
    }
}
@end