ASIHttpRequest下载及断点续传和队列实例

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• 1. 首先先引入几个ASI必须的框架

图1

• 2.引入头文件

#import "ASIHTTPRequest.h" //ASI网络请求
#import "ASINetworkQueue.h"//ASI队列

• 3属性

@interface ViewController ()//此处代理为ProgressView(进度条签定)
@property (nonatomic, retain)ASIHTTPRequest *request;
@property (nonatomic, retain)ASINetworkQueue *netWorkQueue;
@property (nonatomic, retain)UIProgressView *progerssView;
@property (nonatomic, retain)UILabel *label;
@property (nonatomic, assign) BOOL select;

• 4创建一个hanldData

  NSString *urlstring = @"http://hc25.aipai.com/user/656/20448656/6167672/card/25033081/card.mp4";
    //初始化Documents路径
    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
    
    //初始化临时文件路径
    NSString *folderPath = [path stringByAppendingPathComponent:@"temp"];
    //创建文件管理器
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //判断temp文件夹是否存在
    BOOL fileExists = [fileManager fileExistsAtPath:folderPath];
    
    if (!fileExists) {//如果不存在说创建,因为下载时,不会自动创建文件夹
        [fileManager createDirectoryAtPath:folderPath withIntermediateDirectories:YES attributes:nil error:nil];
    }
    
    //设置下载路径
    self.request = [[ASIHTTPRequest alloc] initWithURL:[NSURL URLWithString:urlstring]];
    //设置ASIHTTPRequest代理
   self.request.delegate = self;
    // 设置文件路径下文件夹的名字
    NSString *fileName = [urlstring lastPathComponent];
    //初始化保存ZIP文件路径
    NSString *Savepath = [path stringByAppendingPathComponent:fileName];
    //初始化临时文件路径
    NSString *tempPath = [path stringByAppendingPathComponent:@"linshi"];
    //设置文件保存路径
    [self.request setDownloadDestinationPath:Savepath];
    //设置临时文件路径
    [self.request setTemporaryFileDownloadPath:tempPath];
    //设置进度条的代理,
    [_request setDownloadProgressDelegate:self.progerssView];
   // self.request.downloadProgressDelegate = self.progerssView;
    //[self.request setShowAccurateProgress:YES];
    //设置是是否支持断点下载
    [self.request setAllowResumeForFileDownloads:YES];
    
    //添加到ASINetworkQueue队列去下载
    [self.netWorkQueue go];
    [self.netWorkQueue addOperation:self.request];
    [self.request setCompletionBlock:^{
        NSLog(@"下载成功,文件保存到: %@",NSHomeDirectory());
    }];
    [self.request setFailedBlock:^{
        NSLog(@"下载失败");
    }];

• 5.创建Button

- (void)creaeButton {
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button addTarget:self action:@selector(downloade:) forControlEvents:UIControlEventTouchUpInside];
    button.frame = CGRectMake(100, 180, 80, 30);
    [button setTitle:@"下载" forState:UIControlStateNormal];
    [self.view addSubview:button];   
}

• 6.实现Button点击的方法

- (void)downloade:(UIButton *)sender {
    if ((sender.selected =! sender.selected)) {

        [sender setTitle:@"暂停" forState:UIControlStateNormal];
        [self handleData];

    } else {
        [sender setTitle:@"下载" forState:UIControlStateNormal];
                for (ASIHTTPRequest *request in [self.netWorkQueue operations]) {
                    //暂停的
            [request clearDelegatesAndCancel];
        }
    }
}

• 7.进度条ProgressView的创建

- (void)createProgerssView {
    self.progerssView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleDefault];
    self.progerssView.frame = CGRectMake(50, 100, 200, 20);
    [self.view addSubview:self.progerssView];
    [_progerssView release];
    // 通过KVO监听 progress值,达到监听进图条的目的
    [self.progerssView addObserver:self forKeyPath:@"progress" options:NSKeyValueObservingOptionNew context:nil];
    }

• 8.kvo监听进度条

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object change:(NSDictionary *)change
                       context:(void *)context {
    
    NSNumber *value = [change objectForKey:@"new"];
    float progress = [value floatValue];
    NSLog(@"%.1f%%",progress *100);
    NSString *pro = [NSString stringWithFormat:@"%.1f%%",progress *100];
    self.label.text = pro;
    
    
}

• 9.这是我们在ViewDidLoad方法中进行调用

- (void)viewDidLoad {
    [super viewDidLoad];
    //ASINetworkQueue是NSOperationQueue子类，
    //iPhone 提供了 NSOperation 接口进行任务对象的封装，而通过将任务对象加入到 NSOperationQueue 队列.
    //NSOperationQueue 队列会分配线程进行任务对象的执行.
    self.netWorkQueue  = [ASINetworkQueue queue];
    [self.netWorkQueue reset];
    [self.netWorkQueue setShowAccurateProgress:YES];
    // 设置请求的并发数
   // self.netWorkQueue maxConcurrentOperationCount =
    [self createProgerssView];
    [self creatLabel];
    [self creaeButton];
    // Do any additional setup after loading the view, typically from a nib.
}