iOS 通过网络请求获取图片的下载歌曲

1.导入代理<NSURLConnectionDataDelegate>

@interface ViewController ()<NSURLConnectionDataDelegate>
{
    long long alllength; //下载总长度
    long long currlenth; //当期下载长度
}
//存放下载的mp3 数据流
@property(nonatomic,strong)NSMutableData *msicDate;
//下载进度显示
@property(nonatomic,strong)UIProgressView *msicProgress;
//下载按钮
@property(nonatomic,strong)UIButton *but;
//音乐播放
@property(nonatomic,strong)AVAudioPlayer *player;

//添加下载图片地址
    NSString *path=@"http://pic1.nipic.com/2008-10-27/200810278105878_2.jpg";
    
    //调用下载图片方法
    [self addTheimg:path];
    
    //进度条设置
    self.msicProgress =[[UIProgressView alloc]initWithFrame:CGRectMake(60, 40, 230, 10)];
    self.msicProgress.progress=0;
    //设置下载进度颜色
    self.msicProgress.progressTintColor=[UIColor colorWithRed:0.007 green:0.868 blue:0.000 alpha:1.000];
    //进度条背景颜色
    self.msicProgress.trackTintColor=[UIColor grayColor];
    
    //下载按钮点击下载
    self.but=[UIButton buttonWithType:UIButtonTypeCustom];
    _but.frame=CGRectMake(140, 55, 40, 20);
    [_but setTitleColor:[UIColor whiteColor]forState:UIControlStateNormal];
    [_but setTitle:@"下载" forState:UIControlStateNormal];
    _but.backgroundColor=[UIColor orangeColor];
    [_but addTarget:self action:@selector(plarmusic:) forControlEvents:UIControlEventTouchUpInside];
    
    [self.view addSubview:_msicProgress];
    [self.view addSubview:_but];

方法的实现

//按钮点击时间相应方法
-(void)plarmusic:(UIButton *)sender
{
    //歌曲下载总的长度
    alllength=0;
    //当前获取的量
    currlenth = 0;
    self.msicDate =[[NSMutableData alloc]init];
    //设置歌曲下载的地址
    NSString *path=@"http://yinyueshiting.baidu.com/data2/music/124345627/124104509190800128.mp3?xcode=cb12e87f8333e5370d9b8f0c677c76d2";
    NSURL *url=[NSURL URLWithString:path];
    //方式1 网络请求
    NSURLRequest *requst=[NSURLRequest requestWithURL:url];
    //方式2
    //NSURLRequest *resq=[[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10.0];
    
    //使用代理进行请求 创建连接服务器
    [NSURLConnection connectionWithRequest:requst delegate:self];
}

//实现网络请求代理方法
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    //获取要下载的MP3 的长度，收到响应即可得知，不用下载完毕
    //此代理方法只执行一次,获取总的数据量
    alllength =[response expectedContentLength];
}

//获取每次下载的数据量，此方法可执行多次
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    //将每次下载的数据放入总得数据区域内
    [self.msicDate appendData:data];
    //将本次获取的数据长度追加到当期长度上
    currlenth +=data.length;
    //更新进度条
    self.msicProgress.progress=(float)currlenth/alllength;
}

//下载结束调用，播放音乐
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSError *error=nil;
    //下载完成后，初始化player 然后进行歌曲播放
    self.player = [[AVAudioPlayer alloc]initWithData:self.msicDate error:&error];
    [self.player play];
}

//请求错误调用
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    if (error) {
        NSLog(@"error == %@",error);
    }
}

//调用图片的方法
-(void)addTheimg:(NSString *)path
{
    // 1.通过字符串创建一个url
    NSString *imgstr=path;
    NSURL *imgurl=[NSURL URLWithString:imgstr];
    
    //2. 创建网络请求
    NSURLRequest *requst=[NSURLRequest requestWithURL:imgurl cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10.0];
    
    NSError *error=nil;
    //3. 链接服务器
    NSData *imgDate = [NSURLConnection sendSynchronousRequest:requst returningResponse:nil error:&error];
    if (error)
    {
        //如果错误，打印错误
        NSLog(@"%@",error);
    }else
    {
        //如果找到图片，创建一个图片视图接收图片
        UIImageView *img=[[UIImageView alloc]initWithFrame:CGRectMake(5, 20, 50, 50)];
        img.image=[UIImage imageWithData:imgDate];
        //将图片显示在视图
        [self.view addSubview:img];
    }

}