supersr--NSURLSessionConfiguration-下载进度

//
// ViewController.m
// 下载进度

// Created by Super on 14/7/4.

//

#import "ViewController.h"

@interface ViewController () <NSURLSessionDownloadDelegate>
@property (nonatomic, strong) NSURLSession *session;

@property (nonatomic, strong) NSURLSessionDownloadTask *downloadTask;

@property (nonatomic, strong) NSData *data;

@property (weak, nonatomic) IBOutlet UIProgressView *processView;

@end

@implementation ViewController

- (NSURLSession *)session{
    if (_session == nil) {
        //代理方法运行的队列
        NSOperationQueue *queue = [NSOperationQueue mainQueue];
//        //最大的并发线程数 ???????
        //在NSURLSession中使用NSOperationQueue设置最大并发数，无效
//        queue.maxConcurrentOperationCount = 1;


        NSURLSessionConfiguration *conf = [NSURLSessionConfiguration defaultSessionConfiguration];
        //创建自定义session 设置代理
        //session 会话
        _session = [NSURLSession sessionWithConfiguration:conf delegate:self delegateQueue:queue];
    }
    return _session;
}

//开始下载
- (IBAction)start:(id)sender {
    [self download];
}

//暂停pause 下载

- (IBAction)pause:(id)sender {

//    [self.downloadTask cancel];

    NSLog(@"zan ting");
    //取消下载，并且存储当前下载的数据
    [self.downloadTask cancelByProducingResumeData:^(NSData *resumeData) {
        self.data = resumeData;
    }];
    //如果点击多次暂停会出问题无法继续(因为点击多次暂停的话 resumeData 为空)
    self.downloadTask = nil;

}
//继续下载
- (IBAction)resume:(id)sender {
    if (self.data == nil) {
        NSLog(@"没有要继续的数据");
        return;
    }

    [[self.session downloadTaskWithResumeData:self.data] resume];

    self.data = nil;
}

- (void)download{

//    NSString *strUrl = @"http://127.0.0.1/A02-head.mp4";
    NSString *strUrl = @"http://dlsw.baidu.com/sw-search-sp/soft/9d/25765/sogou_mac_31.1421982306.dmg";
    strUrl = [strUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSURL *url = [NSURL URLWithString:strUrl];
    //使用代理的话，不能用此方法
//    [[self.session downloadTaskWithURL:url completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
//        NSLog(@"---%@",[NSThread currentThread]);
//    }] resume];

    //执行代理方法
    self.downloadTask = [self.session downloadTaskWithURL:url];
    [self.downloadTask resume];
//     [[self.session downloadTaskWithURL:url] resume];
}

//代理的方法

//下载完成 —————>>> didFinishDownloadingToURL

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{
NSLog(@"over");

}

//断点续传 ————>>> didResumeAtOffset

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes{
    NSLog(@"==");
}
//进度
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite{
    NSLog(@"---%@",[NSThread currentThread]);

//    [NSThread sleepForTimeInterval:0.1];
    //bytesWritten 本次下载了多少
    //totalBytesWritten 总共下载了多少
    //totalBytesExpectedToWrite 文件的大小
    float process = totalBytesWritten * 1.0 / totalBytesExpectedToWrite;
    NSLog(@"%f", process);
    self.processView.progress = process;

}

@end