语音识别

* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package com.example.android.apis.app;

import com.example.android.apis.R;

import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.speech.RecognizerIntent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

/**
* Sample code that invokes the speech recognition intent API.
*/
public class VoiceRecognition extends Activity implements OnClickListener {

private static final int VOICE_RECOGNITION_REQUEST_CODE = 1234;

private ListView mList;

/**
* Called with the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

// Inflate our UI from its XML layout description.
setContentView(R.layout.voice_recognition);

// Get display items for later interaction
Button speakButton = (Button) findViewById(R.id.btn_speak);

mList = (ListView) findViewById(R.id.list);

// Check to see if a recognition activity is present
PackageManager pm = getPackageManager();
List activities = pm.queryIntentActivities(
new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0);
if (activities.size() != 0) {
speakButton.setOnClickListener(this);
} else {
speakButton.setEnabled(false);
speakButton.setText("Recognizer not present");
}
}

/**
* Handle the click on the start recognition button.
*/
public void onClick(View v) {
if (v.getId() == R.id.btn_speak) {
startVoiceRecognitionActivity();
}
}

/**
* Fire an intent to start the speech recognition activity.
*/
private void startVoiceRecognitionActivity() {
Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,
RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
intent.putExtra(RecognizerIntent.EXTRA_PROMPT, "Speech recognition demo");
startActivityForResult(intent, VOICE_RECOGNITION_REQUEST_CODE);
}

/**
* Handle the results from the recognition activity.
*/
@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 matches = data.getStringArrayListExtra(
RecognizerIntent.EXTRA_RESULTS);
mList.setAdapter(new ArrayAdapter(this, android.R.layout.simple_list_item_1,
matches));
}

super.onActivityResult(requestCode, resultCode, data);
}
}