UIActivityViewController与备用文件名？

Question

我正在通过UIActivityViewController分享录音。通过电子邮件或iMessage共享音频文件时，它会显示音频文件的基础名称，而无需任何明显的更改方式。

NSArray *activityItems = [NSArray arrayWithObjects:self.audioPlayer.url, nil];

UIActivityViewController *avc = [[UIActivityViewController alloc]
                                 initWithActivityItems:activityItems
                                 applicationActivities:nil];
[self presentViewController:avc
                   animated:YES completion:nil];

如果我不使用UIActivityViewController而仅直接使用MFMessageComposeViewController，那么我可以使用

[composer addAttachmentURL:self.audioPlayer.url withAlternateFilename:@"Piano Song.m4a"];

UIActivityViewController是否可以使用备用文件名？

Answer 1

非常好，timaktimak。谢谢。在 Swift 中也是如此：

    private func createLinkToFile(atURL fileURL: URL, withName fileName: String) -> URL? {
        let fileManager = FileManager.default               // the default file maneger
        let tempDirectoryURL = fileManager.temporaryDirectory   // get the temp directory
        let linkURL = tempDirectoryURL.appendingPathComponent(fileName) // and append the new file name
        do {                                                // try the operations
            if fileManager.fileExists(atPath: linkURL.path) {   // there is already a hard link with that name
                try fileManager.removeItem(at: linkURL)     // get rid of it
            }
            try fileManager.linkItem(at: fileURL, to: linkURL)  // create the hard link
            return linkURL                                  // and return it
        } catch let error as NSError {                      // something wrong
            print("\(error)")                               // debug print out
            return nil                                      // and signal to caller
        }
    }

Answer 2

您可以使用临时目录中想要的任何名称来创建指向该文件的硬链接（这样就不必复制实际文件），并将其传递给UIActivityViewController而不是文件。

- (NSURL *)createLinkToFileAtURL:(NSURL *)fileURL withName:(NSString *)fileName {
    NSFileManager *fileManager = [NSFileManager defaultManager];

    // create a path in the temp directory with the fileName
    NSURL *tempDirectoryURL = [[NSFileManager defaultManager] temporaryDirectory];
    NSURL *linkURL = [tempDirectoryURL URLByAppendingPathComponent:fileName];

    // if the link already exists, delete it
    if ([fileManager fileExistsAtPath:linkURL.path]) {
        NSError *error;
        [fileManager removeItemAtURL:linkURL error:&error];
        if (error) {
            // handle the error
        }
    }

    // create a link to the file
    NSError *error;
    BOOL flag = [fileManager linkItemAtURL:fileURL toURL:linkURL error:&error];
    if (!flag || error) {
        // handle the error
    }
    return linkURL;
}

像这样使用它：

NSURL *fileURL = ...;
NSString *desiredName = ...;

NSURL *linkURL = [self createLinkToFileAtURL:fileURL withName:desiredName];
UIActivityViewController *viewController = [[UIActivityViewController alloc] initWithActivityItems:@[linkURL] applicationActivities:nil];
[self presentViewController:viewController animated:YES completion:nil];

希望这可以帮助！祝好运！

Answer 3

不，不可能。您不能在共享文件之前重命名该文件吗？