- Widget
- Handler
- Service
Ex ： 2015/05/12 17:00
需要在code裡不斷的重新更新時間，下面這段code就是new出一個新的時間並設定我們需要的格式。
new SimpleDateFormat( "yyyy/MM/dd HH:mm:ss" ).format( new Date())
在Widget的部分主要是要intent Service交由Service去處理我們的每秒更新與背景。
Widget.java
public class SmsWidget extends AppWidgetProvider {
Context context_main ;
AppWidgetManager app_manager;
int []appWidgetId;
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
app_manager = appWidgetManager;
context_main = context;
appWidgetId = appWidgetIds;
//new出一個 intent並將Widget的context傳入
Intent intent = new Intent(context_main,WidgetService.class);
//Intent執行service服務
context_main.startService(intent);
}
@Override
public void onEnabled(Context context) {
}
@Override
public void onDisabled(Context context) {
//當WidgetDisable時關閉service服務
Intent intent = new Intent(context_main,WidgetService.class);
context_main.stopService(intent);
}
}
那我們要如何不斷的new出新的時間並更新widget的view ?
其實只要用handler來處理即可，並搭配Service讓code在背景執行，執行一次就更新一秒。
Service.java
public class WidgetService extends Service {
private Handler mHandlerBoss = null;
private HandlerThread mHandlerEmployee = null;
private String EmployeeName = "John";
public WidgetService() {
}
@Override
public void onDestroy() {
super.onDestroy();
//service結束，結束handler
mHandlerBoss.removeCallbacks(mRunnable);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
//建立Handler
//Handler簡單來說就是需要老闆、員工、工作
//建立一個員工
mHandlerEmployee = new HandlerThread(EmployeeName);
//員工上班
mHandlerEmployee.start();
//建立一個老闆，老闆聘員工上班
mHandlerBoss = new Handler(mHandlerEmployee.getLooper());
//老闆指派工作給員工
mHandlerBoss.post(mRunnable);
return super.onStartCommand(intent, flags, startId);
}
private Runnable mRunnable = new Runnable() {
@Override
public void run() {
//更新Widget畫面
buildUpdate();
//每秒跑一次
mHandlerBoss.postDelayed(this,1000);
}
};
private void buildUpdate()
{
RemoteViews view = new RemoteViews(getPackageName(), R.layout.sms_widget);
view.setTextViewText(R.id.appwidget_text, new SimpleDateFormat( "yyyy/MM/dd HH:mm:ss" ).format( new Date()));
ComponentName thisWidget = new ComponentName(this, SmsWidget.class);
AppWidgetManager manager = AppWidgetManager.getInstance(this);
manager.updateAppWidget(thisWidget, view);
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
}
編譯成功後就能夠在，手機裡將Widget拉出來使用。
參考連結：
Widget Update http://stackoverflow.com/questions/4866305/android-widget-update
背景執行 http://cooking-java.blogspot.tw/2010/04/android-service.html
