网络热恋之NSURLSession

//
//  ViewController.m
//  NSURLSession代理简介

#import "ViewController.h"

@interface ViewController ()<NSURLSessionDataDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

}
//这是为了测试而建立的点击屏幕事件。
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    //代理 测试

    NSURL * url = [NSURL URLWithString:@"http://localhost/login.php?username=haha&password=123"];

    //创建自定义Session

    NSURLSession * session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc]init]];

    NSURLSessionTask * task = [session dataTaskWithURL:url];
    //开启任务
    [task resume];

}
#pragma mark - deleDate
//接受到服务器响应
-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
{
    //__FUNCTION__ c语言字符串用s
    NSLog(@"%s",__FUNCTION__);

    //允许服务器回传数据
    completionHandler(NSURLSessionResponseAllow);

}
//接受服务器回传的数据可能执行多次
-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data{

    NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);

}
//请求成功或者失败
-(void)URLSession:(NSURLSession *)session didBecomeInvalidWithError:(NSError *)error{
    NSLog(@"%@",error);
}
@end

上面简单介绍了一下

然后我们来看一个demo

其中下载文件的地址，读者可以自己配置

 //
 //  ViewController.m
 //  NSURLSession大文件下载
 //
 //

 #import "ViewController.h"

 @interface ViewController ()<NSURLSessionDownloadDelegate>

 @property (nonatomic, strong) NSURLSessionDownloadTask * task;

 @property (nonatomic, strong) NSData * resumeData;

 @property (nonatomic, strong) NSURLSession * session;

 @end

 @implementation ViewController

 - (IBAction)start:(id)sender {

     NSURLSession * session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];

     self.session = session;

     self.task = [session downloadTaskWithURL:[NSURL URLWithString:[@"http://192.168.1.200/DOM解析.mp4"stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]];

     [self.task resume];
 }

 - (IBAction)pause:(id)sender {

     //暂停就是将任务挂起

     [self.task cancelByProducingResumeData:^(NSData * _Nullable resumeData) {

         //保存已下载的数据
         self.resumeData = resumeData;
     }];
 }

 - (IBAction)resume:(id)sender {

     //可以使用ResumeData创建任务

     self.task = [self.session downloadTaskWithResumeData:self.resumeData];

     //开启继续下载
     [self.task resume];

 }

 - (void)viewDidLoad {
     [super viewDidLoad];
     // Do any additional setup after loading the view, typically from a nib.

     NSLog(@"%@",NSSearchPathForDirectoriesInDomains(, , ));
 }

 /* 

  监测临时文件下载的数据大小，当每次写入临时文件时，就会调用一次

  bytesWritten 单次写入多少
  totalBytesWritten  已经写入了多少
  totalBytesExpectedToWrite 文件总大小

  */

 - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask
       didWriteData:(int64_t)bytesWritten
  totalBytesWritten:(int64_t)totalBytesWritten
 totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {

     //打印下载百分比
     NSLog(@"%f",totalBytesWritten * 1.0 / totalBytesExpectedToWrite);

 }

 //下载完成

 - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask
 didFinishDownloadingToURL:(NSURL *)location {

     NSString * cachesPath = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:downloadTask.response.suggestedFilename];

     NSFileManager * mgr = [NSFileManager defaultManager];

     [mgr moveItemAtURL:location toURL:[NSURL fileURLWithPath:cachesPath] error:NULL];

 }

 - (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error {

     NSLog(@"%@",error);
 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 @end