iPhone SDK:如何将视频文件下载到文档目录然后播放？

Question

我一直在为这个代码愚弄代码,如果有人能提供从服务器http://www.archive.org/download/june_high/june_high_512kb.mp4下载此文件的代码示例,我将非常感激.,(顺便说一下,它实际上不是这个文件,它只是一个试图帮助我的人的完美例子),然后从文档目录中播放它.我知道这对我来说似乎很懒,但我尝试了很多不同的NSURLConnection变种,这让我发疯了.此外,如果我确实设法下载了视频文件,我会认为这个代码会成功播放它是正确的:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"june_high_512kb.mp4"]; 
NSURL *movieURL = [NSURL fileURLWithPath:path]; 
self.theMovie = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
[_theMovie play];

如果上面的代码可以在文档目录中播放视频文件,那么我想我唯一需要知道的是,如何从服务器下载视频文件.这似乎是我的主要问题.任何帮助是极大的赞赏.

Answer 1

您的代码将用于播放电影文件.

最简单的下载方式是同步:

NSData *data = [NSData dataWithContentsOfURL:movieUrl];
[data writeToURL:movieUrl atomically:YES];

但是异步下载更好(对于应用程序响应等):

    NSURLRequest *theRequest = [NSURLRequest requestWithURL:movieUrl cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60];
    receivedData = [[NSMutableData alloc] initWithLength:0];
        NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self startImmediately:YES];

这需要实现非正式的NSURLConnection协议:

- (void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
    [receivedData setLength:0];
}

- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [receivedData appendData:data];
}

- (void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    [connection release];
}

- (NSCachedURLResponse *) connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse {
    return nil;
}

- (void) connectionDidFinishLoading:(NSURLConnection *)connection {
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    [connection release];
    [self movieReceived];
}

然后在movieReceived方法中保存(并播放)电影文件.