objective-c - 无法将文件从包复制到文档目录，为什么 fileExistsAtPath 返回错误？

Question

我正在使用以下代码片段尝试将文件从我的应用程序资源目录复制到文档区域。我使用了 PocketOCR 中的以下内容Github 上的项目:

// Set up the tessdata path. This is included in the application bundle
    // but is copied to the Documents directory on the first run.
    NSString *dataPath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:@"tessdata"];
    NSFileManager *fileManager = [NSFileManager defaultManager];

    NSLog(@"Datapath is %@", dataPath);
    // If the expected store doesn't exist, copy the default store.
    if (![fileManager fileExistsAtPath:dataPath ]) {
        NSLog(@"File didn't exist at datapath...");
        // get the path to the app bundle (with the tessdata dir)
        NSString *bundlePath = [[NSBundle mainBundle] bundlePath];
        NSString *tessdataPath = [bundlePath stringByAppendingPathComponent:@"tessdata"];
        if (tessdataPath) {
            [fileManager copyItemAtPath:tessdataPath toPath:dataPath error:NULL];
        }
    }

这是我调用上面的命令得到的输出:

2012-06-06 14:53:42.607 MyApp[1072:707] Datapath is /var/mobile/Applications/9676D920-D6D1-4F86-9177-07CC3247A124/Documents/tessdata Error opening data file /var/mobile/Applications/9676D920-D6D1-4F86-9177-07CC3247A124/Documents/tessdata/eng.traineddata

我的 xcode 项目中有 eng.traineddata 文件，就像这样

似乎在尝试检查 fileExistsAtPath 时报告了错误，我不希望这会引发错误，而是返回 YES 或 NO。

是否有更简单的方法来复制 eng.traineddata 文件，或者我犯了一个可以在这里更正的错误？

Answer 1

NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;

NSString *dataPath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:@"tessdata"];
NSLog(@"Datapath is %@", dataPath);

// If the expected store doesn't exist, copy the default store.    
    if ([fileManager fileExistsAtPath:dataPath] == NO)
    {
        NSString *tessdataPath = [[NSBundle mainBundle] pathForResource:@"eng" ofType:@"traineddata"];
        [fileManager copyItemAtPath:tessdataPath toPath:dataPath error:&error];

    }


-(NSString*) applicationDocumentsDirectory{
    // Get the documents directory
    NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *docsDir = [dirPaths objectAtIndex:0];
    return docsDir;
}