UIDocumentInteractionController显示文件名和文件类型，而不是文件内容

Question

我有NSData，我保存在文件目录中的文件夹中，文件扩展名为.pdf＆amp;当我尝试使用UIDocumentInteractionController打开它时，它只向我显示文件名＆amp;类型，而不是内容。我检查了文件目录文件夹中的模拟器和放大器那里有一个.pdf文件。

//Saving NSData
+ (NSString *)createTempDocumentDirectory:(NSString *)dirName
                         andStoreData:(NSData *)data
                         withFileName:(NSString *)name
                     andFileExtension:(NSString *)extension
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0]; // Fetch path for document directory
    NSMutableString *dirPath = (NSMutableString *)[documentsDirectory stringByAppendingPathComponent:dirName];
    NSString *fileName = [NSString stringWithFormat:@"%@.%@", name, extension];
    NSString *path = [dirPath stringByAppendingPathComponent:fileName];

    return path;
}                         //Presenting contents of view

- (void)loadDocumentPreview:(NSURL *)fileURL
{    
    if (fileURL)
    {
        self.documentInteractionController = [UIDocumentInteractionController interactionControllerWithURL:[self fileURLDocumentPath:documentPath]];
        self.documentInteractionController.name = @"";
        [self.documentInteractionController setDelegate:self];
        [self.documentInteractionController presentPreviewAnimated:YES];
    }
}