Question

所以我试图用NSURLConnection下载一本ePub书。到目前为止，下载工作正常。当我尝试保存并打开它时会出现问题。当我尝试使用UIDocumentInteractionController打开它时，应用程序崩溃说该目录为空。

这是我的代码：

 //Download ePub file
 NSURL *url = [NSURL URLWithString:@"http://www.terceiroanjo.com/materiais/missaopiloto.epub"];
 NSURLRequest *theRequest = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:10.0];
 connection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];

然后

// save it ("data" = NSMutableData that was appended from the received data of the download)
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
     NSString  *filePath = [NSString stringWithFormat:@"%u/%@", NSDocumentDirectory,@"missaopiloto.epub"];
     [data writeToFile:filePath atomically:YES];
}

并打开ePub：

 NSString *path = [[NSBundle mainBundle] pathForResource:@"missaopiloto" ofType:@"epub"];
 NSURL *urls = [NSURL fileURLWithPath:path];

 self.documentController = [UIDocumentInteractionController interactionControllerWithURL:urls];
 documentController.delegate = self;

 [documentController presentOpenInMenuFromRect:CGRectZero inView:self.view animated:YES];

当我尝试打开它时，应用程序崩溃了：

*由于未捕获的异常终止应用＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39; * - [NSURL initFileURLWithPath：]：nil字符串参数＆＃39;

我明白了，目录是nill，但为什么呢？我究竟做错了什么。有什么想法吗？

感谢。

Answer 1

我认为这里的问题是，一旦下载并保存文件，它就不会成为捆绑包的一部分。

如果要访问该文件，则必须提供本地路径并创建本地URL

NSString  *path = [NSString stringWithFormat:@"%u/%@", NSDocumentDirectory,@"missaopiloto.epub"];
NSURL *urls = [NSURL fileURLWithPath:path];

self.documentController = [UIDocumentInteractionController interactionControllerWithURL:urls];
documentController.delegate = self;

[documentController presentOpenInMenuFromRect:CGRectZero inView:self.view animated:YES];

下载ePub（NSURLConnection），保存并使用UIDocumentInteractionController打开它

1 个答案: