如何确认嵌入的设备（运行Android OS）是否有扬声器

Question

I want to confirm embeded device(running android OS 5.1.1) whether has a speaker or not. I try AuidoManager#isSpeakerphoneOn, no matter I insert or remove speaker, it always return false。

I'm wondering how to solve this problem.

Answer 1

You can put a to only install on devices with a way of outputting sound. I don't think there is an API to tell if it currently has a speaker.

Answer 2

You can use PackageManager class' PackageManager#hasSystemFeature(String) to check whether the given feature is present or not at runtime.

More specifically, you can query PackageManager#hasSystemFeature(String) using the constant FEATURE_AUDIO_OUTPUT which returns true if the device includes at least one form of audio output, such as speakers, audio jack or streaming over bluetooth.

PackageManager pm = getPackageManager();
if(pm.hasSystemFeature(PackageManager.FEATURE_AUDIO_OUTPUT){
  // audio output device present
} else {
  // no audio output device present
}

Or, you can also use the <uses-feature> element in the AndroidManifest.xml with android:name set to android.hardware.audio.output and require equals to true which will prevent your app from being installed on devices with no audio output device.