Android ApiDemos示例解析(46)：App->Voice Recognition

這個例子需要Android系統中安裝了支持RecognizerIntent.ACTION_RECOGNIZE_SPEECH的應用，比如Google的 Voice Search 應用。

模擬器上缺省沒有安裝，可以參見如何在Android emulator上安裝 APK 在模擬器上安裝一個Voice Search。

本例 VoiceRecognition首先通過PackageManager檢測本機是否安裝了支持RecognizerIntent.ACTION_RECOGNIZE_SPEECH，如果有，則 Enable Speak按鈕，否則顯示“Recognizer not present”

// 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) {
 speakButton.setOnClickListener(this);
} else {
 speakButton.setEnabled(false);
 speakButton.setText("Recognizer not present");
}

如果本機上安裝了Google的Voice Search，點擊“Speak!”則會啟動語音輸入對話框：