iOS- 利用AFNetworking3.0+（最新AFN) - 实现文件断点下载

1 @interface ViewController ()
2 {
3     // 下载句柄
4     NSURLSessionDownloadTask *_downloadTask;
5 }

 1 .h文件
 2 #import <UIKit/UIKit.h>
 3  
 4 @interface ViewController : UIViewController
 5 // 下载文件显示
 6  
 7 @property (weak, nonatomic) IBOutlet UIImageView *imageView;
 8 // 下载进度条显示
 9  
10 @property (weak, nonatomic) IBOutlet UIProgressView *progressView;
11 @end
12  
13 .m文件
14 @interface ViewController ()
15 {
16     // 下载句柄
17     NSURLSessionDownloadTask *_downloadTask;
18 } 

 1 - (void)downFileFromServer{
 2     
 3     //远程地址
 4     NSURL *URL = [NSURL URLWithString:@"http://www.baidu.com/img/bdlogo.png"];
 5     //默认配置
 6     NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
 7     
 8     //AFN3.0+基于封住URLSession的句柄
 9     AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration];
10     
11     //请求
12     NSURLRequest *request = [NSURLRequest requestWithURL:URL];
13     
14     //下载Task操作
15     _downloadTask = [manager downloadTaskWithRequest:request progress:^(NSProgress * _Nonnull downloadProgress) {
16         
17         // @property int64_t totalUnitCount;     需要下载文件的总大小
18         // @property int64_t completedUnitCount; 当前已经下载的大小
19         
20         // 给Progress添加监听 KVO
21         NSLog(@"%f",1.0 * downloadProgress.completedUnitCount / downloadProgress.totalUnitCount);
22         // 回到主队列刷新UI
23         dispatch_async(dispatch_get_main_queue(), ^{
24         // 设置进度条的百分比
25  
26             self.progressView.progress = 1.0 * downloadProgress.completedUnitCount / downloadProgress.totalUnitCount;
27         });
28  
29     } destination:^NSURL * _Nonnull(NSURL * _Nonnull targetPath, NSURLResponse * _Nonnull response) {
30         
31         //- block的返回值, 要求返回一个URL, 返回的这个URL就是文件的位置的路径
32  
33         NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
34         NSString *path = [cachesPath stringByAppendingPathComponent:response.suggestedFilename];
35         return [NSURL fileURLWithPath:path];
36  
37     } completionHandler:^(NSURLResponse * _Nonnull response, NSURL * _Nullable filePath, NSError * _Nullable error) {
38         //设置下载完成操作
39         // filePath就是你下载文件的位置，你可以解压，也可以直接拿来使用
40         
41         NSString *imgFilePath = [filePath path];// 将NSURL转成NSString
42         UIImage *img = [UIImage imageWithContentsOfFile:imgFilePath];
43         self.imageView.image = img;
44  
45     }];
46 }

1 - (IBAction)stopDownloadBtnClick:(id)sender {
2     //暂停下载
3     [_downloadTask suspend];
4 }
5 - (IBAction)startDownloadBtnClick:(id)sender {
6     //开始下载
7     [_downloadTask resume];
8 }

 1 - (void)viewDidLoad {
 2     [super viewDidLoad];
 3     
 4     //网络监控句柄
 5     AFNetworkReachabilityManager *manager = [AFNetworkReachabilityManager sharedManager];
 6     
 7     //要监控网络连接状态，必须要先调用单例的startMonitoring方法
 8     [manager startMonitoring];
 9     
10     [manager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
11         //status:
12         //AFNetworkReachabilityStatusUnknown          = -1,  未知
13         //AFNetworkReachabilityStatusNotReachable     = 0,   未连接
14         //AFNetworkReachabilityStatusReachableViaWWAN = 1,   3G
15         //AFNetworkReachabilityStatusReachableViaWiFi = 2,   无线连接
16         NSLog(@"%d", status);
17     }];
18     
19     //准备从远程下载文件. -> 请点击下面开始按钮启动下载任务
20     [self downFileFromServer];
21  
22 }