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在我的 android 应用程序中，我在启动活动的 onCreate 方法中调用语音识别。我已经优先选择是否启动语音控制。但是，当语音识别开启时，应用程序大约需要 5-7 秒才能加载。当它关闭时，应用程序几乎立即启动。下面是示例代码，我添加了 Free_Form、max_results 1 和自定义提示。

Intent intent = new Intent("android.speech.action.RECOGNIZE_SPEECH");  
startActivityForResult(intent, 0);

所以我真的有两个问题：

startActivity(intent) 不是在单独的线程中运行吗？

为什么在我的 OnCreate 方法中调用普通的 android 语音识别需要很长时间才能加载？

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2 回答 2

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您可能不会等待从 onCreate 完成该过程，而是启动它以便结果将返回到回调处理程序，或者创建一个线程并从那里启动它。

于 2010-10-01T17:40:05.850 回答
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在我的摩托罗拉 Droid 上，语音识别的设置不需要 5-7 秒，它是 <0.5 秒，所以你的代码可能有另一个问题。尽管如此，这里是将准备工作从 onCreate 移动到后台线程的代码：

public class VoiceRecognition extends Activity implements OnClickListener {

private static final int VOICE_RECOGNITION_REQUEST_CODE = 1234;
ImageButton speechButton;
static List<ResolveInfo> systemActivities=null;
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
    speechButton = (ImageButton) findViewById(R.id.btn_speak);
    mList = (ListView) findViewById(android.R.id.list);
    // Asynchronously activate speech recognition
    new getSpeechTask().execute();
}
private class getSpeechTask extends AsyncTask<Void,Void,List<ResolveInfo>>{
    protected List<ResolveInfo> doInBackground(Void...params) {
        List<ResolveInfo> sysAct=null;
        if(sysAct==null){
            PackageManager pm = getPackageManager();
            sysAct = pm.queryIntentActivities(
                    new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0
            );
        }
        return sysAct;
    }//doInBackground
    protected void onPostExecute(List<ResolveInfo> result) {
        systemActivities=result;    
        setSpeechStatus();
    }//apply result
}//getSpeechTask    
void setSpeechStatus(){
    if(systemActivities.size()>0){
        speechButton.setOnClickListener(
            new OnClickListener(){
                @Override
                public void onClick(View v) {
                    startVoiceRecognitionActivity();
                }
            }
        );
        speechButton.setEnabled(true);  
    }else{
        speechButton.setEnabled(false); 
    }
}
void startVoiceRecognitionActivity(){
    if(systemActivities==null){
        PackageManager pm = getPackageManager();
        systemActivities = pm.queryIntentActivities(
                new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0);
        setSpeechStatus();
    }
    Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
    intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,
            RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
    intent.putExtra(RecognizerIntent.EXTRA_PROMPT, "Missive(c) Speech Input");
    startActivityForResult(intent, VOICE_RECOGNITION_REQUEST_CODE);
}

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


/**
 * 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<String> matches = data.getStringArrayListExtra(
                RecognizerIntent.EXTRA_RESULTS);
        mList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
                matches));
    }

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

使用 layout.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <ListView android:id="@android:id/list"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/hello"
    />
   <ImageButton android:id="@+id/btn_speak"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:src="@android:drawable/ic_btn_speak_now"
   />
</LinearLayout>
于 2011-06-15T05:00:32.700 回答