想学习一下android studio上面的google voice recognition的code， 在网上找了
sample code之后， 在华为荣耀8实机上运行，button上显示“recognizer not present”.
显示这个实机的Android version 是 7.0，API level 27
下面是MainActivity.java
```public class MainActivity extends Activity {
private static final String TAG = "VoiceRecognition";
private static final int VOICE_RECOGNITION_REQUEST_CODE = 1234;
private final int AUDIO_REQUEST_CODE = 3;
private TextView textView;
private Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initWidget();
// Check to see if a recognition activity is present
PackageManager pm = getPackageManager();
List<ResolveInfo> activities = pm.queryIntentActivities(
new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0);
if (activities.size() != 0) {
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (ContextCompat.checkSelfPermission(MainActivity.this,
Manifest.permission.RECORD_AUDIO) == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(MainActivity.this, "You have already granted this permission!",
Toast.LENGTH_SHORT).show();
} else {
requestStoragePermission();
}
startVoiceRecognitionActivity();
}
});
} else {
button.setEnabled(false);
button.setText("Recognizer not present");
}
}
private void requestStoragePermission() {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.RECORD_AUDIO)) {
new AlertDialog.Builder(this)
.setTitle("Permission needed")
.setMessage("This permission is needed because of this and that")
.setPositiveButton("ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(MainActivity.this,
new String[] {Manifest.permission.RECORD_AUDIO}, AUDIO_REQUEST_CODE);
}
})
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
})
.create().show();
} else {
ActivityCompat.requestPermissions(this,
new String[] {Manifest.permission.RECORD_AUDIO}, AUDIO_REQUEST_CODE);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == AUDIO_REQUEST_CODE) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(this, "Permission GRANTED", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Permission DENIED", Toast.LENGTH_SHORT).show();
}
}
}
private void initWidget()
{
textView = (TextView)findViewById(R.id.tv);
button = (Button)findViewById(R.id.btn);
}
/**
* Fire an intent to start the speech recognition activity.
*/
private void startVoiceRecognitionActivity() {
Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
// Display an hint to the user about what he should say.
intent.putExtra(RecognizerIntent.EXTRA_PROMPT, "Please speak now");//注意不要硬编码
// Given an hint to the recognizer about what the user is going to say
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,
RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
// Specify how many results you want to receive. The results will be sorted
// where the first result is the one with higher confidence.
intent.putExtra(RecognizerIntent.EXTRA_MAX_RESULTS, 1);//通常情况下，第一个结果是最准确的。
startActivityForResult(intent, VOICE_RECOGNITION_REQUEST_CODE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == VOICE_RECOGNITION_REQUEST_CODE && resultCode == RESULT_OK) {
// Fill the list view with the strings the recognizer thought it could have heard
ArrayList<String> matches = data.getStringArrayListExtra(
RecognizerIntent.EXTRA_RESULTS);
StringBuilder stringBuilder = new StringBuilder();
int Size = matches.size();
for(int i=0;i<Size;++i)
{
stringBuilder.append(matches.get(i));
stringBuilder.append("\n");
}
textView.setText(stringBuilder);
}
super.onActivityResult(requestCode, resultCode, data);
}}
```
顺带一提，这个code在上图的API level 22，Android 5.1的虚拟机是可以运行的，但是
在API level 27，Android 8.0就出现了直接跳到“try again”界面（下图）
在Android 5.1
在Android 8.0
总结一下，其实是两个问题，这个code在华为Android 7.0的实机上无法加载google voice recognition的dialog， 在虚拟机Android8.0 虽然可以加载dialog， 但是无法正常运行voice recognition， 在Android 5.1上可以正常运行。之前有提问过一次，有回答说是6.0后permission的问题，这个code已经加了runtime permission确保麦克风是有permission的，但是问题依然存在。请大神帮忙看下问题到底出在哪。谢谢。
