Question

我有一个在iphone（sdk 4）中实现的音乐播放器，它既适用于Mp3流媒体（即时转码）或原始渐进式下载。

有没有让渐进式内容（我不直接控制）被缓存，所以它不会重新下载整个内容？

或者是否需要控制全局缓存设置？（另一方面，我使用ASIHTTP API联系我的HTTP服务器并访问允许缓存的数据）。

提前致谢。

Answer 1

您可以使用NSURLConnection保存文件并进行播放。

示例：

-(void)downloadFileAtPath:(NSString *)path
{
     NSURL *url                  = [NSURL URLWithString:path];     
     NSMutableURLRequest *req    = [NSMutableURLRequest requestWithURL:url];
      NSURLConnection* connection = [[NSURLConnection alloc] initWithRequest:req delegate:self];
    [connection start];
}

-(void)connection:(NSURLConnection*)connection didReceiveResponse:(NSURLResponse*)response
{
    //NSLog(@"%s", __PRETTY_FUNCTION__);
    [[NSFileManager defaultManager] createFileAtPath:pathForCurrentFile contents:nil attributes:nil];
     currentFile = [NSFileHandle fileHandleForUpdatingAtPath:pathForCurrentFile];
     if (currentFile)
    {
        [currentFile seekToEndOfFile];
    }
}

-(void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data
{
    //NSLog(@"%s", __PRETTY_FUNCTION__);
     if( currentFile != nil){
         if (currentFile)  {
            [currentFile seekToEndOfFile];
        }
        [currentFile writeData:data];
    }
}

-(void)connection:(NSURLConnection*)connection didFailWithError:(NSError*)error
{
    NSLog(@"%s, %@", __PRETTY_FUNCTION__, error);
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    [currentFile closeFile];
}

以下是播放代码

//Playback
 NSString *loopFilePath = [[self applicationDocumentsDirectory].path stringByAppendingPathComponent:vidFileName];

NSURL *vidURL = [NSURL fileURLWithPath:vidFilePath];

self.vidController = [[MPMoviePlayerController alloc] initWithContentURL:vidURL];
self.vidController.view.frame = CGRectMake(0, 0, 640, 480);
self.vidController.controlStyle = MPMovieControlStyleDefault;
[self.view addSubview:self.vidController.view];
[self.vidController prepareToPlay];
[self.vidController play];

缓存在MPMoviePlayerController中逐行下载的内容

1 个答案: