java - 无法停止android后台服务

Question

我正在运行以下后台服务:

public class TranslationService  extends IntentService implements ClipboardManager.OnPrimaryClipChangedListener {

    private Language mFrom;
    private Language mTo;
    private String mTranslation;
    private ClipboardManager mClipboardManager;

    public TranslationService() {
        super("hello");
    }

    public TranslationService(String name) {
        super(name);
    }

    @Override
    protected void onHandleIntent(Intent intent) {

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        mFrom = (Language) intent.getSerializableExtra(MainActivity.FROM_STRING);
        mTo = (Language) intent.getSerializableExtra(MainActivity.TO_STRING);
        mClipboardManager = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
        mClipboardManager.addPrimaryClipChangedListener(this);

        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onPrimaryClipChanged() {

        ClipData clip = mClipboardManager.getPrimaryClip();
        String copiedText = clip.getItemAt(0).getText().toString();
        connectToTranslationApi(copiedText);

        //TODO solve concurrency problems if app works inconsistently.
        try {
           Thread.sleep(500);
        } catch (InterruptedException e) {
           e.printStackTrace();
        }

            new Handler(Looper.getMainLooper()).post(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getBaseContext(), mTranslation, Toast.LENGTH_SHORT).show();
                }
            });

    }

    private void connectToTranslationApi(String copiedPhrase) {

        String apiKey = "xxxxxxxxxxxxxxxxxxxxxxxxxxx";
        String fromInitials = mFrom.initials;
        String toInitials = mTo.initials;
        String yandexUrl = "https://translate.yandex.net/api/v1.5/tr.json/translate?key="+
                apiKey + "&lang=" +
                fromInitials + "-" + toInitials +
                "&text="+ copiedPhrase;

        OkHttpClient okHttpClient = new OkHttpClient();
        Request request = new Request.Builder().url(yandexUrl).build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                //TODO handle failure
            }

            @Override
            public void onResponse(Response response) throws IOException {
                if (response.isSuccessful()) {
                    String jsonData = response.body().string();
                    try {mTranslation = getTextTranslation(jsonData);}
                    catch (JSONException e) {e.printStackTrace();}
                }
            }
        });
    }

    private String getTextTranslation(String jsonData) throws JSONException {
        JSONObject data = new JSONObject(jsonData);
        String translation = data.getString("text");
       translation = translation.replace("]", "")
                    .replace("[", "")
                    .replace("\"", "");
        return translation;
    }

}

该服务在后台运行，并翻译我复制到剪贴板的文本(即使我使用其他应用程序。只有当我从 RAM 中删除启动它的应用程序时，该服务才会停止)，这一切都很好。

但是，当我返回应用程序的主要 Activity 并按“停止服务”时，它不会停止。这是启动(并应该停止)服务的代码

         if(mIsServiceRunning == false) {
            Intent i = new Intent(MainActivity.this, TranslationService.class);
            i.putExtra(FROM_STRING, mLanguageFrom);
            i.putExtra(TO_STRING, mLanguageTo);
            startService(i);
            mIsServiceRunning = true;
            startButton.setText("Stop Service");
            Toast.makeText(this, "Service Started", Toast.LENGTH_SHORT).show();
        }
        else {
            Intent i = new Intent(MainActivity.this, TranslationService.class);
            stopService(i);
            mIsServiceRunning = false;
            startButton.setText("Start Service");
        }

有什么想法可以阻止它吗？

Answer 1

我不完全确定您如何确定您的服务仍在运行。但我建议不要将其基于 mIsServiceRunning boolean 值。

您可以使用此方法来确保它是否正在运行:

public static boolean isServiceRunning(Class<?> serviceClass) {
  ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
  for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
    if (serviceClass.getName().equals(service.service.getClassName())) {
      return true;
    }
  }
  return false;
}

此方法将返回一个 boolean 值，告诉您该服务是否在后台运行，例如，您可以像这样使用它:

if (isServiceRunning(TranslationService.class)) {
  Toast.makeText(this, "Service is Running", Toast.LENGTH_SHORT).show();
} else {
  Toast.makeText(this, "Service is NOT Running", Toast.LENGTH_SHORT).show();
}

也许我也错过了它，但我在你的代码中没有看到任何错误。

context.stopService(new Intent(context, TranslationService.class));

应该停止你的服务。

希望对您有帮助，如果没有，请在尝试后尝试提供更多信息。