Android 语音输入API使用

原文链接：http://www.javaarch.net/jiagoushi/782.htm

Android 语音输入API使用

Android已经支持语音输入的API了，不过不知道中文输入识别效果怎么样。这里给一个怎么使用语音输入的示例

首先在android工程中的页面布局文件中res/layout/main.xml添加一个button和text

	<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
		xmlns:tools="http://schemas.android.com/tools"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:layout_above="@+id/textView1"
		android:layout_toLeftOf="@+id/textView1"
		android:gravity="center"
		android:orientation="vertical" >
	 
		<ImageButton
			android:id="@+id/btnSpeak"
			android:layout_width="fill_parent"
			android:layout_height="wrap_content"
			android:layout_margin="10dp"
			android:layout_marginRight="10dp"
			android:layout_marginTop="10dp"
			android:contentDescription="@string/speak"
			android:src="@android:drawable/ic_btn_speak_now" />
	 
		<TextView
			android:id="@+id/txtText"
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:layout_marginLeft="10dp"
			android:layout_marginRight="10dp"
			android:layout_marginTop="10dp"
			android:textAppearance="?android:attr/textAppearanceLarge" />
	 
	</LinearLayout>
	
active类SpeechToTextDemoActivity.java

	package net.viralpatel.android.speechtotextdemo;
	 
	import java.util.ArrayList;
	 
	import android.app.Activity;
	import android.content.ActivityNotFoundException;
	import android.content.Intent;
	import android.os.Bundle;
	import android.speech.RecognizerIntent;
	import android.view.Menu;
	import android.view.View;
	import android.widget.ImageButton;
	import android.widget.TextView;
	import android.widget.Toast;
	 
	public class MainActivity extends Activity {
	 
		protected static final int RESULT_SPEECH = 1;
	 
		private ImageButton btnSpeak;
		private TextView txtText;
	 
		@Override
		public void onCreate(Bundle savedInstanceState) {
			super.onCreate(savedInstanceState);
			setContentView(R.layout.activity_main);
	 
			txtText = (TextView) findViewById(R.id.txtText);
	 
			btnSpeak = (ImageButton) findViewById(R.id.btnSpeak);
	 
			btnSpeak.setOnClickListener(new View.OnClickListener() {
	 
				@Override
				public void onClick(View v) {
	 
					Intent intent = new Intent(
							RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
	 
					intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, "en-US");
	 
					try {
						startActivityForResult(intent, RESULT_SPEECH);
						txtText.setText("");
					} catch (ActivityNotFoundException a) {
						Toast t = Toast.makeText(getApplicationContext(),
								"Opps! Your device doesn't support Speech to Text",
								Toast.LENGTH_SHORT);
						t.show();
					}
				}
			});
	 
		}
	 
		@Override
		public boolean onCreateOptionsMenu(Menu menu) {
			getMenuInflater().inflate(R.menu.activity_main, menu);
			return true;
		}
	 
		@Override
		protected void onActivityResult(int requestCode, int resultCode, Intent data) {
			super.onActivityResult(requestCode, resultCode, data);
	 
			switch (requestCode) {
			case RESULT_SPEECH: {
				if (resultCode == RESULT_OK && null != data) {
	 
					ArrayList<String> text = data
							.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
	 
					txtText.setText(text.get(0));
				}
				break;
			}
	 
			}
		}
	}
	
这里android.speech是Android语音输入的核心包，android.speech.RecognizerIntent是一个主要的类，这个active会弹出一个语音输入对话框，然后接收语音输入，识别语音内容转为文本，但我们启动语音输入active后，需要通过startActivityForResult()方法接收文本结果。在.putExtra()方法还需要输入RecognizerIntent.EXTRA_LANGUAGE_MODE语言类型，这里是en-US。

我们通过覆盖onActivityResult(int requestCode, int resultCode, Intent data)方法来处理结果数据，通过data获取key为RecognizerIntent.EXTRA_RESULTS来接收文本内容list，然后设置到text框上。

示例代码地址：http://viralpatel-net-tutorials.googlecode.com/files/SpeechToTextDemo.zip