SpeechRecognizer.isRecognitionAvailable在Android 11中始终为false

问题描述

顾名思义，SpeechRecognizer.isRecognitionAvailable()在Android 11中返回false，我不确定为什么会这样，因为设备（Pixel 3 XL）可以识别语音。 documentation并不表示它在API v30中已更改。奇怪的是，即使isRecognitionAvailable为假，我仍然可以成功获得STT提示。下面是说明这一点的示例代码。为什么isRecognitionAvailable检查始终为假？该代码无论如何都不完整，但是我添加了重要的相关部分：

AndroidManifest.xml
...
<uses-permission android:name="android.permission.RECORD_AUdio" />
...

MainActivity.kt
...
override fun onCreate(savedInstanceState: Bundle?) {
...
    if(ContextCompat.checkSelfPermission(this,Manifest.permission.RECORD_AUdio) != PackageManager.PERMISSION_GRANTED) {
        if(shouldShowRequestPermissionRationale(Manifest.permission.RECORD_AUdio)) { //rationale prompt
        }
        val requestPermissionLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission()
        ){ isGranted: Boolean ->
            if(isGranted) { checkSTT() }
            else { //error perms not granted
            }
        requestPermissionLauncher.launch(Manifest.permission.RECORD_AUdio)
    } else { checkSTT() }
}

private fun checkSTT() {
    if(SpeechRecognizer.isRecognitionAvailable(this)) { runSTT() }
    else { runSTT() //Run anyway because isRecognitionAvailable is always false and STT works anyway?
    }
}

private fun runSTT() {
    //Yes,I kNow this is deprecated
    val sttIntent = Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH)
    sttIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,RecognizerIntent.LANGUAGE_MODEL_FREE_FORM)
    sttIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE,Locale.US)
    startActivityForResult(sttIntent,1)
}
...

解决方法

我想出了解决方案。由于某些原因，从API v30开始，必须将以下内容添加到清单文件中，SpeechRecognizer.isRecognitionAvailable(Context)才能返回true。我的测试发现，即使它抱怨“此处不允许元素查询”，它也只能在置于<application>标记之外时起作用。添加suppress AndroidElementNotAllowed删除警告。

<!--suppress AndroidElementNotAllowed -->
<queries>
    <intent>
        <action android:name="android.speech.RecognitionService" />
    </intent>
</queries>
<application...