ios - UIDocumentInteractionController "invalid scheme (null)"

Question

我正在尝试使用 UIDocumentInteractionController 预览文档。该文档是我的应用程序从网上下载的 .xls 文件。我不断收到此错误:

'UIDocumentInteractionController: invalid scheme (null).  Only the file scheme is supported.'

我使用下一个代码:

- (void) webServiceController:(WebServiceController *)webServiceController returnedArray:(NSMutableArray *)array {
    if ([webServiceController.webRequest isEqualToString: @"generateExcelFileForEmployee"]) {
        // start previewing the document at the current section index
        NSString *link = [[NSString stringWithString:array[0]] stringByReplacingOccurrencesOfString:@"AdminFunctions.php" withString:@"AdminFunctions.xls"];
        link = [[[link stringByReplacingOccurrencesOfString:@"\\" withString:@""]stringByReplacingOccurrencesOfString:@"/public/sites/" withString:@"http://"]stringByReplacingOccurrencesOfString:@"\"\\\"" withString:@""];
        NSLog(@"%@", link);
        NSData *urlData = [NSData dataWithContentsOfURL:[NSURL URLWithString:link]];

        NSArray   *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString  *documentsDirectory = [paths objectAtIndex:0];

        NSString  *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"AdminFunctions.xls"];

        BOOL isWriteSuccess = [urlData writeToFile:filePath atomically:YES];
        NSLog(@"%@", filePath);

        if(isWriteSuccess) //success
        {
            file = [NSURL fileURLWithPath:filePath];

            self.fileView = [self setupControllerWithURL:file usingDelegate:self];

            [self.fileView presentPreviewAnimated:YES];
        }
        else
        {
           NSLog(@"file not written");
        }
    }
}

- (UIDocumentInteractionController *) setupControllerWithURL: (NSURL*) fileURL usingDelegate: (id <UIDocumentInteractionControllerDelegate>) interactionDelegate {

    UIDocumentInteractionController *interactionController =
    [UIDocumentInteractionController interactionControllerWithURL: fileURL];
    interactionController.delegate = interactionDelegate;

    return interactionController;
}

- (UIViewController *) documentInteractionControllerViewControllerForPreview: (UIDocumentInteractionController *) controller {
    return self;
}

这两种方法都在我要显示预览的 View Controller 中实现。我非常清楚我正在获取 urlData 对象中的数据，因为当我设置断点时，控制台显示它包含 6144 字节，这正是要下载的文档的大小。

我一直在安静地寻找这个问题，但我似乎无法弄清楚如何解决这个问题。我已经尝试将 link 对象作为 documentInteractionController 的来源，但随后错误变为:

'UIDocumentInteractionController: invalid scheme (http).  Only the file scheme is supported.'

任何关于我如何克服这个问题的评论都将不胜感激

Answer 1

尝试使用

// objC
file = [NSURL fileURLWithPath:filePath];
// swift
file = URL.init(fileURLWithPath: filePath)

代替

//objC
file = [NSURL URLWithString:filePath];
// swift
file = URL.init(string: filePath)