倒计时器在后台更新ui

Question

我有倒数计时器，倒计时用户设定的当前时间。虽然，我希望能够访问其他应用程序，或者只是在倒数计时器运行时转到设备的主屏幕，并继续使用倒计时中剩余的计时器更新文本视图。有没有办法做到这一点？我尝试实现下面的服务，但我不知道这是否是完成此任务的正确方法，因为我收到了错误。

% git add [a-j]*
% git st                                                                                                                                               
On branch master
Your branch is up-to-date with 'origin/master'.
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        new file:   a.rb
        new file:   b.rb

Untracked files:
  (use "git add <file>..." to include in what will be committed)

        y.rb
        z.rb

Answer 1

您需要使用服务和广播接收器。 我为你创建了一些example for broadcast receiver。

检查一下，如果您有任何问题，请告诉我。

创建服务：TimerService.java

C:\wamp\www\myfirstgit

在MainActivity.java中

 @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        //Initialize and start the counter
        countDown = new HokusFocusCountDownTimer(timeDifference, 1000);

            countDown.start();

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

希望我的回答对您有所帮助

Answer 2

实际上您需要Alarm Manager + Broadcast Receiver

当您的广播接收器等待警报管理器信号时，您的警报管理器是倒计时的一员。

修改

完整的代码可以在GUI updater repo中下载。

示例代码段

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="io.github.ecobin.gui_refresh_by_time" >

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service
            android:name=".UpdateService"
            android:enabled="true"
            android:exported="true" >
        </service>
    </application>

</manifest>

MainActivity

    public class MainActivity extends Activity {

        public static final String[] WORD_BANK = {"Hello World!", "Ice cream", "Soda", "Cake", "Apple"};
        public static final int TIMER = 10; // 10 seconds timer.
        public TextView textView;

        IntentFilter fil;
        BroadcastReceiver receiver;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            textView = (TextView) findViewById(R.id.hello_world);

            fil = new IntentFilter("mybroadcast");
            receiver = new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {
                    Log.i(">>>>>>>>>>>", "Updating UI!");
                    updateGUI();
                }
            };

            AlarmManager manager = (AlarmManager) getSystemService(ALARM_SERVICE);
            Intent in = new Intent(this, UpdateService.class);
            PendingIntent pending = PendingIntent.getService(this, 1234, in, 0);

            manager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, 1000 * TIMER, 1000 * TIMER, pending);
        }

        @Override
        protected void onPause() {
            super.onPause();
            unregisterReceiver(receiver);
        }

        @Override
        protected void onResume() {
            super.onResume();
            registerReceiver(receiver, fil);
        }


// MORE CODE HERE......

        public void updateGUI() {
            int randomNumber = (int) (Math.random() * WORD_BANK.length);
            textView.setText(WORD_BANK[randomNumber]);
        }
    }