Android获取应用是否开启通知栏及跳转到设置界面

判断通知权限

方式一

在代码中通过NotificationManagerCompat包获取是否打开了通知显示权限：

NotificationManagerCompat manager = NotificationManagerCompat.from(App.getInstance().getContext());
boolean isOpened = manager.areNotificationsEnabled();

NotificationManagerCompat位于v4包内，所以需要引入v4包。

要注意的是，areNotificationsEnabled方法的有效性官方只最低支持到API 19，低于19的仍可调用此方法不过只会返回true，即默认为用户已经开启了通知。 查了各种资料，目前暂时没有办法获取19以下的系统是否开启了某个App的通知显示权限。

方式二

通过反射获取通知栏是否显示

最低支持到API 19，android8.0上返回的都是true

/**
 * 获取通知栏权限是否开启
 * 
 */

public class NotificationsUtils {
   private static final String CHECK_OP_NO_THROW = "checkOpNoThrow";
   private static final String OP_POST_NOTIFICATION = "OP_POST_NOTIFICATION";

   @SuppressLint("NewApi")
   public static boolean isNotificationEnabled(Context context) {

      AppOpsManager mAppOps = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE);
      ApplicationInfo appInfo = context.getApplicationInfo();
      String pkg = context.getApplicationContext().getPackageName();
      int uid = appInfo.uid;

      Class appOpsClass = null;
      /* Context.APP_OPS_MANAGER */
      try {
         appOpsClass = Class.forName(AppOpsManager.class.getName());
         Method checkOpNoThrowMethod = appOpsClass.getMethod(CHECK_OP_NO_THROW, Integer.TYPE, Integer.TYPE,
               String.class);
         Field opPostNotificationValue = appOpsClass.getDeclaredField(OP_POST_NOTIFICATION);

         int value = (Integer) opPostNotificationValue.get(Integer.class);
         return ((Integer) checkOpNoThrowMethod.invoke(mAppOps, value, uid, pkg) == AppOpsManager.MODE_ALLOWED);

      } catch (ClassNotFoundException e) {
         e.printStackTrace();
      } catch (NoSuchMethodException e) {
         e.printStackTrace();
      } catch (NoSuchFieldException e) {
         e.printStackTrace();
      } catch (InvocationTargetException e) {
         e.printStackTrace();
      } catch (IllegalAccessException e) {
         e.printStackTrace();
      }
      return false;
   }
}

打开应用详情界面

// 根据isOpened结果，判断是否需要提醒用户跳转AppInfo页面，去打开App通知权限
Intent intent = new Intent();
intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", App.getInstance().getApplication().getPackageName(), null);
intent.setData(uri);
startActivity(intent);

打开应用通知设置界面

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    Intent intent = new Intent();
    intent.setAction("android.settings.APP_NOTIFICATION_SETTINGS");
    intent.putExtra("app_package", getActivity().getPackageName());
    intent.putExtra("app_uid", getActivity().getApplicationInfo().uid);
    startActivity(intent);
} else if (android.os.Build.VERSION.SDK_INT == Build.VERSION_CODES.KITKAT) {
    Intent intent = new Intent();
    intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
    intent.addCategory(Intent.CATEGORY_DEFAULT);
    intent.setData(Uri.parse("package:" + getActivity().getPackageName()));
    startActivity(intent);
}