iOS 文档分享相关

　　　　在非系统预览情况下  指定文件打开系统分享菜单

　　　　　　　NSString *savedPath = [NSHomeDirectory() stringByAppendingString:[NSString stringWithFormat:@"/Documents/%@",filname]];
            NSFileManager *fileManager = [NSFileManager defaultManager];
            NSURL *URL = [NSURL fileURLWithPath:savedPath];
            if (URL) {
                [self setupDocumentControllerWithURL:URL];
                [self.docInteractionController setDelegate:self];
                [self.docInteractionController presentOptionsMenuFromRect:[actionSheet frame] inView:self.view animated:YES];
            }