如何在没有 Google API 的情况下在安卓系统上开发语音识别器？

此示例演示了如何在没有 Google API 的情况下在安卓系统上开发语言识别器。

步骤 1 − 在 Android Studio 中创建一个新项目，转到文件 ⇒ 新项目，然后填写所有必要信息以创建一个新项目。

步骤 2 − 将以下代码添加到 res/layout/activity_main.xml。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical" >
   <ImageView
      android:id="@+id/imageView1"
      android:layout_width="200dp"
      android:layout_height="200dp"
      android:layout_centerInParent="true"
      android:src="@drawable/ic_mic" />
   <ProgressBar
      android:id="@+id/progressBar1" style="?android:attr/progressBarStyleHorizontal"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_alignParentLeft="true"
      android:layout_below="@+id/toggleButton1"
      android:layout_marginTop="28dp"
      android:paddingLeft="10dp"
      android:paddingRight="10dp" />
   <TextView
      android:id="@+id/textView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@+id/progressBar1"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="47dp" />
   <ToggleButton
      android:id="@+id/toggleButton1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="26dp"
      android:text="ToggleButton" />
</RelativeLayout>

步骤 3 − 将以下代码添加到 src/MainActivity.java

package app.com.sample;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.speech.RecognitionListener;
import android.speech.RecognizerIntent;
import android.speech.SpeechRecognizer;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.CompoundButton;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ToggleButton;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity implements
RecognitionListener {
   private static final int REQUEST_RECORD_PERMISSION = 100;
   private TextView returnedText;
   private ToggleButton toggleButton;
   private ProgressBar progressBar;
   private SpeechRecognizer speech = null;
   private Intent recognizerIntent;
   private String LOG_TAG = "VoiceRecognitionActivity";
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      returnedText = findViewById(R.id.textView1);
      progressBar = findViewById(R.id.progressBar1);
      toggleButton = findViewById(R.id.toggleButton1);
      progressBar.setVisibility(View.INVISIBLE);
      speech = SpeechRecognizer.createSpeechRecognizer(this);
      Log.i(LOG_TAG, "isRecognitionAvailable: " + SpeechRecognizer.isRecognitionAvailable(this));
      speech.setRecognitionListener(this);
      recognizerIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
      recognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_PREFERENCE,"US-en");
      recognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
      recognizerIntent.putExtra(RecognizerIntent.EXTRA_MAX_RESULTS, 3);
      toggleButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
         @Override
         public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked) {
               progressBar.setVisibility(View.VISIBLE);
               progressBar.setIndeterminate(true);
               ActivityCompat.requestPermissions (MainActivity.this, new String[]{Manifest.permission.RECORD_AUDIO},
               REQUEST_RECORD_PERMISSION);
            } else {
               progressBar.setIndeterminate(false);
               progressBar.setVisibility(View.INVISIBLE);
               speech.stopListening();
            }
         }
      });
   }
   @Override
   public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
      super.onRequestPermissionsResult(requestCode, permissions, grantResults);
      switch (requestCode) {
         case REQUEST_RECORD_PERMISSION:
         if (grantResults.length > 0 && grantResults[0]== PackageManager.PERMISSION_GRANTED) {
            speech.startListening(recognizerIntent);
         } else {
            Toast.makeText(MainActivity.this, "Permission Denied!", Toast .LENGTH_SHORT).show();
         }
      }
   }
   @Override
   public void onResume() {
      super.onResume();
   }
   @Override
   protected void onPause() {
      super.onPause();
   }
   @Override
   protected void onStop() {
      super.onStop();
      if (speech != null) {
         speech.destroy();
         Log.i(LOG_TAG, "destroy");
      }
   }
   @Override
   public void onBeginningOfSpeech() {
      Log.i(LOG_TAG, "onBeginningOfSpeech");
      progressBar.setIndeterminate(false);
      progressBar.setMax(10);
   }
   @Override
   public void onBufferReceived(byte[] buffer) {
      Log.i(LOG_TAG, "onBufferReceived: " + buffer);
   }
   @Override
   public void onEndOfSpeech() {
      Log.i(LOG_TAG, "onEndOfSpeech");
      progressBar.setIndeterminate(true);
      toggleButton.setChecked(false);
   }
   @Override
   public void onError(int errorCode) {
      String errorMessage = getErrorText(errorCode);
      Log.d(LOG_TAG, "FAILED " + errorMessage);
      returnedText.setText(errorMessage);
      toggleButton.setChecked(false);
   }
   @Override
   public void onEvent(int arg0, Bundle arg1) {
      Log.i(LOG_TAG, "onEvent");
   }
   @Override
   public void onPartialResults(Bundle arg0) {
      Log.i(LOG_TAG, "onPartialResults");
   }
   @Override
   public void onReadyForSpeech(Bundle arg0) {
      Log.i(LOG_TAG, "onReadyForSpeech");
   }
   @Override
   public void onResults(Bundle results) {
      Log.i(LOG_TAG, "onResults");
      ArrayList<String> matches = results .getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION);
      String text = "";
      for (String result : matches)
         text = result + "
";
      returnedText.setText(text);
   }
   @Override
   public void onRmsChanged(float rmsdB) {
      Log.i(LOG_TAG, "onRmsChanged: " + rmsdB);
      progressBar.setProgress((int) rmsdB);
   }
   public static String getErrorText(int errorCode) {
      String message;
      switch (errorCode) {
         case SpeechRecognizer.ERROR_AUDIO:
            message = "Audio recording error";
            break;
         case SpeechRecognizer.ERROR_CLIENT:
            message = "Client side error";
            break;
         case
            SpeechRecognizer.ERROR_INSUFFICIENT_PERMISSIONS:
            message = "Insufficient permissions";
            break;
         case SpeechRecognizer.ERROR_NETWORK:
            message = "Network error";
            break;
         case SpeechRecognizer.ERROR_NETWORK_TIMEOUT:
            message = "Network timeout";
            break;
         case SpeechRecognizer.ERROR_NO_MATCH:
            message = "No match";
            break;
         case SpeechRecognizer.ERROR_RECOGNIZER_BUSY:
            message = "RecognitionService busy";
            break;
         case SpeechRecognizer.ERROR_SERVER:
            message = "error from server";
            break;
         case SpeechRecognizer.ERROR_SPEECH_TIMEOUT:
            message = "No speech input";
            break;
         default:
            message = "Didn't understand, please try
            again.";
            break;
      }
      return message;
   }
}

步骤 4 − 将以下代码添加到 androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <uses-permission android:name="android.permission.RECORD_AUDIO"/>
   <uses-permission android:name="android.permission.INTERNET" />
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>