iphone - 如何将音频文件从服务器下载到我的 iPhone 应用程序中？

Question

我有一个 iPhone 应用程序，可以从服务器播放音频文件 (mp3)，我想添加一个下载按钮，以便用户可以将这些文件下载到应用程序中。因此，他/她每次想要收听这些文件时都不需要互联网连接。有人有相关的示例代码吗？

我在网上看到了很多东西，但我仍然很困惑。 这是我正在使用的代码:

在 .h 文件中:

#import 
#import "MBProgressHUD.h"

#import 
#import 

@interface myViewController : UIViewController {
MBProgressHUD *HUD;

long long expectedLength;
long long currentLength;

AVAudioPlayer *theAudio;

}

-(NSString *)pathOfFile;
-(void)applicationWillTerminate:(NSNotification*)notification;

-(IBAction)play:(id)sender;
-(IBAction)download(id)sender;
@property (nonatomic,retain) AVAudioPlayer *theAudio;

在 .m 文件中:

- (IBAction)download:(id)sender {
NSURL *URL = [NSURL URLWithString:@"http://www.server.com/myfile.mp3"];
NSURLRequest *request = [NSURLRequest requestWithURL:URL];

NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request      delegate:self];
[connection start];
[connection release];

HUD = [[MBProgressHUD showHUDAddedTo:self.navigationController.view animated:YES] retain];

HUD.labelText = @"Loading...";
}

-(IBAction)play:(id)sender { 

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *file = [NSString stringWithFormat:@"%@/song.mp3", documentsDirectory];

theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:file]   error:nil];

[theAudio play];

}

-(NSString *)pathOfFile {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

return [documentsDirectory stringByAppendingFormat:@"myfile.plist"];

}

-(void)applicationWillTerminate:(NSNotification*)notification {

NSMutableArray *array = [[NSMutableArray alloc]init];
[array addObject:theAudio];
[array writeToFile:[self pathOfFile] atomically:YES];

[array release];

}

我不知道问题出在哪里，或者我在这里缺少什么，您能帮我提供更多详细信息吗？ 提前致谢。

Answer 1

使用ASIHTTP下载，异步且更可靠。 http://allseeing-i.com/ASIHTTPRequest/ 这是您可以下载音频/视频的方法。向其传递参数并开始下载？

参数: (1) 文件路径，要保存的文档目录路径 (2) Trimmed String ，即讲座URL

+ (void)downloadingLecture:(NSString *)filePath withLectureUrl:(NSString *)trimmedString 
 {
    AppDelegate *_appDel=(AppDelegate *)[[UIApplication sharedApplication] delegate];
    [_appDel.queue setDelegate:self];
    [_appDel.queue setMaxConcurrentOperationCount:10];
    [_appDel.queue setShouldCancelAllRequestsOnFailure:NO];
    [_appDel.queue setShowAccurateProgress:YES];

    ASIHTTPRequest *request;
    request = [ASIHTTPRequest requestWithURL:[NSURL URLWithString:trimmedString]];
    [request setDelegate:self];
    [request setDownloadDestinationPath:filePath];
    [request setShowAccurateProgress:YES];
    [request setShouldContinueWhenAppEntersBackground:YES];
    [request setUsername:downloadedSuccessfullString];
    [request setDidFinishSelector:@selector(downloadedSuccessfully:)];
    [request setDidFailSelector:@selector(downloadedFailure:)];

    [_appDel.queue addOperation:request];
    [_appDel.queue go];
}

希望这对您有帮助。如果仍然存在问题，请给我发电子邮件，我确信我会这样做，因为我已经在我的两个应用程序中实现了它。