我正在创建一个简单的应用程序我目前发现的是，当我打开我的应用程序时，在.gradle文件夹中设置了以下权限：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
然而，我的应用程序有一个名为Gvoice.java的第二个活动，然后依赖谷歌语音文本。
我发现如果我在.gradle文件夹中保留上述权限，我的主活动窗口与pocketsphinx完美配合。然而，我的Gvoice活动给了我一个消息'Can't open microphone'。
但我发现如果我删除.gradle文件夹中的三个权限。我的主要活动不再做我想要它做的事情，但我的第二个活动叫Gvoice现在正确地将语音转换成文本并且不给我'Can't open microphone'消息。
有没有一种简单的方法来解决这个问题，因为我认为它肯定与麦克风权限有关。还请注意，每当我返回主活动时，需要设置权限，当我在主活动之外的另一个活动时，它需要禁用权限（或者如果有另一种方法，则执行此操作）。
是否可以为清单文件中的不同活动设置不同的权限？
下面我已经更新了我到目前为止所看到的内容请看看：
public class PocketSphinxActivity extends Activity implements RecognitionListener
{
private static final String KWS_SEARCH = "wakeup";
/* Keyword we are looking for to activate menu */
private static final String KEYPHRASE = "open voice command"; //adjust this keyphrase here and in string!
private SpeechRecognizer recognizer;
private HashMap<String, Integer> captions;
ListView lv;
TextView tv;
EditText a;
Button b;
Button c;
Boolean isDone = false;
@Override
public void onCreate(Bundle state) {
super.onCreate(state);
// Prepare the data for UI
captions = new HashMap<String, Integer>();
captions.put(KWS_SEARCH, R.string.kws_caption);
setContentView(R.layout.main);
((TextView) findViewById(R.id.caption_text))
.setText("Preparing the recognizer");
lv = (ListView) findViewById(R.id.lvVoiceReturn);
tv = (TextView) findViewById(R.id.result_text);
a = (EditText) findViewById(R.id.TFusername);
b = (Button) findViewById(R.id.bVoice);
c = (Button)findViewById(R.id.Blogin);
// Recognizer initialization is a time-consuming and it involves IO,
// so we execute it in async task
new AsyncTask<Void, Void, Exception>() {
@Override
protected Exception doInBackground(Void... params) {
try {
Assets assets = new Assets(PocketSphinxActivity.this);
File assetDir = assets.syncAssets();
setupRecognizer(assetDir);
} catch (IOException e) {
return e;
}
return null;
}
@Override
protected void onPostExecute(Exception result) {
if (result != null) {
((TextView) findViewById(R.id.caption_text))
.setText("Failed to init recognizer " + result);
} else {
switchSearch(KWS_SEARCH);
}
}
}.execute();
//line added.../////////////////////////
a.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (s.toString().trim().equalsIgnoreCase("open voice command")) {
//
//Do your stuff here OR button.performClick()
//
//DELAY
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (!isDone) {
b.performClick();
isDone = true;
}
}
}, 500);
}
}
@Override
public void afterTextChanged(Editable s) {
}
});
////////////////////////////////////////
}
@Override
public void onDestroy() {
super.onDestroy();
recognizer.cancel();
recognizer.shutdown();
}
/**
* In partial result we get quick updates about current hypothesis. In
* keyword spotting mode we can react here, in other modes we need to wait
* for final result in onResult.
*/
@Override
public void onPartialResult(Hypothesis hypothesis) {
if (hypothesis == null)
return;
String text = hypothesis.getHypstr();
//((TextView) findViewById(R.id.result_text)).setText(text);
((EditText) findViewById(R.id.TFusername)).setText(text);
}
/**
* This callback is called when we stop the recognizer.
*/
@Override
public void onResult(Hypothesis hypothesis) {
//((TextView) findViewById(R.id.result_text)).setText("");
((EditText) findViewById(R.id.TFusername)).setText("");
if (hypothesis != null) {
String text = hypothesis.getHypstr();
makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show();
//a.setText((String) tv.getText());
//tv = TextView.getText().toString();
}
}
@Override
public void onBeginningOfSpeech() {
}
/**
* We stop recognizer here to get a final result
*/
@Override
public void onEndOfSpeech() {
if (!recognizer.getSearchName().equals(KWS_SEARCH))
switchSearch(KWS_SEARCH);
}
private void switchSearch(String searchName) {
recognizer.stop();
// If we are not spotting, start listening with timeout (10000 ms or 10 seconds).
if (searchName.equals(KWS_SEARCH))
recognizer.startListening(searchName);
else
recognizer.startListening(searchName, 10000);
String caption = getResources().getString(captions.get(searchName));
((TextView) findViewById(R.id.caption_text)).setText(caption);
}
private void setupRecognizer(File assetsDir) throws IOException {
// The recognizer can be configured to perform multiple searches
// of different kind and switch between them
recognizer = defaultSetup()
.setAcousticModel(new File(assetsDir, "en-us-ptm"))
.setDictionary(new File(assetsDir, "cmudict-en-us.dict"))
// To disable logging of raw audio comment out this call (takes a lot of space on the device)
.setRawLogDir(assetsDir)
// Threshold to tune for keyphrase to balance between false alarms and misses
.setKeywordThreshold(1e-45f)
// Use context-independent phonetic search, context-dependent is too slow for mobile
.setBoolean("-allphone_ci", true)
.getRecognizer();
recognizer.addListener(this);
/** In your application you might not need to add all those searches.
* They are added here for demonstration. You can leave just one.
*/
// Create keyword-activation search.
recognizer.addKeyphraseSearch(KWS_SEARCH, KEYPHRASE);
}
@Override
public void onError(Exception error) {
((TextView) findViewById(R.id.caption_text)).setText(error.getMessage());
}
@Override
public void onTimeout() {
switchSearch(KWS_SEARCH);
}
//Assign button clicks to go to a new activity:
public void onButtonClick_1(View v){
if (v.getId() == R.id.bVoice){
String str_1 = a.getText().toString();
//Go to the relevant page if any part of the phrase or word entered in the 'EditText' field contains 'command' which is not case sensitive
if (str_1.toLowerCase().contains("command")) {
Intent userintent = new Intent(PocketSphinxActivity.this, Gvoice.class);
startActivity(userintent);
} else {
Toast.makeText(getApplicationContext(), "Incorrect Information", Toast.LENGTH_SHORT).show();
}
}
}
我在评论中说：
使用noHistory不是解决方案，它恰好适用于大多数情况。当您的应用不再位于前台时，由于收到来电等原因，您不希望丢失用户体验，而是希望暂停用户体验。正确管理onPause和onResume是一个基本的基本要求，使用noHistory将暂时避开你。
以下是当您的应用暂停并随后恢复时如何管理recognizer对象的示例。
@Override
protected void onResume() {
super.onResume();
if (recognizer == null) {
// Set up recognizer again
}
}
@Override
protected void onPause() {
super.onPause();
if (recognizer != null) {
recognizer.cancel();
recognizer.shutdown();
recognizer = null;
}
}
虽然每次暂停时都会销毁你的应用程序，但会解决释放麦克风和识别器资源的问题，这不是你想做的事情 - 你希望优雅地管理你的应用程序进入后台并进入前台的生命周期再一次，没有您持有的资源（如麦克风）导致其他应用程序出现问题。
我已经想出了另一种方法是将以下内容添加到我的清单文件android:noHistory="true"中，这似乎清除了主活动堆栈的历史记录，现在onClickListener正在第二个活动中工作。
另一种方法是将以下内容放在我的MainActivity文件的底部，这是@brandall建议的onPause方法：
@Override
protected void onPause() {
super.onPause();
finish();
}