ios - 文件路径为零

Question

大家好，我是 ios 的新手

这是我的代码

       NSArray   *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
       NSString  *documentsDirectory = [paths objectAtIndex:0];
       NSString *comicbook_id = [[NSUserDefaults standardUserDefaults]stringForKey:@"comicbook_id"];
       NSString  *filePath = [NSString stringWithFormat:@"%@/book_%@.pdf", documentsDirectory,comicbook_id];



       documentsDirectory = [documentsDirectory stringByAppendingPathComponent:filePath];

       NSLog(@"date==>%@",documentsDirectory);
       ***here i am getting path***
       ReaderDocument *document = [ReaderDocument withDocumentFilePath:documentsDirectory password:nil];
      NSLog(@"date==>%@",document); 

*****here i am getting <nil>***** 


       if (document != nil) {

           ReaderViewController *readerViewController = [[ReaderViewController alloc] initWithReaderDocument:document];
           readerViewController.delegate = self;
           readerViewController.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"background.png"]];
           readerViewController.navigationController.navigationBar.tintColor = [UIColor blackColor];

           readerViewController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
           readerViewController.modalPresentationStyle = UIModalPresentationFullScreen;

           [self presentViewController:readerViewController animated:YES completion:nil];
} 

Answer 1

而不是这个:

NSString  *filePath = [NSString stringWithFormat:@"%@/book_%@.pdf", documentsDirectory,comicbook_id];

使用

 NSString  *filePath = [documentsDirectory stringByAppendingPathComponent:[NSString  stringWithFormat:@"book_%@.pdf",comicbook_id]];