如何修改Expo-AV录制文件（FileSystem）的文件名？

Got it, let's get your recording filenames changed from the default recording-*.3gp to NameOfApp-*.3gp — it's straightforward once you know how to specify a custom output URI with expo-av!

Here's what you need to do: #

The default filename comes from expo-av automatically generating a URI when you don't specify one. To override this, you'll construct a custom file URI using expo-file-system to get a valid storage path, plus a unique identifier to avoid overwriting files.

Step 1: Install required dependencies (if missing)

You'll need expo-file-system (for directory access) and optionally expo-crypto (to generate a reliable unique ID):

npx expo install expo-file-system expo-crypto

Step 2: Build your custom file URI

In your recording logic, create a URI that uses your app name plus a unique ID. Here's a code snippet:

import { Audio } from 'expo-av';
import * as FileSystem from 'expo-file-system';
import * as Crypto from 'expo-crypto';

// Function to create a custom recording URI
async function getCustomRecordingURI() {
  // Get the app's document directory (where recordings are stored by default)
  const documentDir = FileSystem.documentDirectory;
  // Generate a unique UUID to avoid duplicate filenames
  const uuid = await Crypto.randomUUID();
  // Replace "YourAppName" with your actual app name
  return `${documentDir}YourAppName-${uuid}.3gp`;
}

Step 3: Use the custom URI when starting a recording

When you initialize your recording, pass the custom URI to Audio.Recording.createAsync():

async function startRecording() {
  try {
    // Request recording permission (you probably already have this)
    const permission = await Audio.requestPermissionsAsync();
    if (!permission.granted) return;

    // Initialize audio mode
    await Audio.setAudioModeAsync({
      allowsRecordingIOS: true,
      playsInSilentModeIOS: true,
    });

    // Get your custom URI
    const recordingURI = await getCustomRecordingURI();

    // Create the recording with your custom URI
    const { recording } = await Audio.Recording.createAsync(
      Audio.RecordingOptionsPresets.HIGH_QUALITY,
      recordingURI // This is the key line to override the default filename
    );

    // Store the recording instance for later use (playback, stopping, etc.)
    this.recording = recording;
    console.log('Recording started with URI:', recordingURI);
  } catch (err) {
    console.error('Failed to start recording:', err);
  }
}

Key Notes: #

• File Format: We're keeping the .3gp extension since that's what you're using now — expo-av supports this format by default, so no changes needed there.
• Unique IDs: Using Crypto.randomUUID() ensures each filename is unique, preventing accidental overwrites of old recordings.
• Storage Location: FileSystem.documentDirectory is the default location expo-av uses, so your recordings will still be stored in the same place, just with the new filename.

That's it! Now every recording you make will have the format YourAppName-<unique-id>.3gp instead of the default.

内容的提问来源于stack exchange，提问作者Drioueche Mohammed