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(, , , )];
     self.msicProgress.progress=;
     //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(, , , );
     [_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=;
     //当前获取的量
     currlenth = ;
     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(, , , )];
         img.image=[UIImage imageWithData:imgDate];
         //将图片显示在视图
         [self.view addSubview:img];
     }

 }