android widget textview動態更新

我目前正在學習Android中的小部件。我希望能夠更新我的textview，但每當我嘗試更新它時 - 我的程序崩潰。這裏是我的課：android widget textview動態更新

public class DayWidget extends AppWidgetProvider { 

    public static CheckDate CheckDate; 
    public static EventList EventList; 

    public static String EVENT_CLICK = "EventClick"; 
    public String msg; 

    public RemoteViews views; 
    public AppWidgetManager manager; 
    public Context cntxt; 
    public Intent intnt; 
    public int[] ids; 

    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds){ 
     super.onUpdate(context, appWidgetManager, appWidgetIds); 

     CheckDate = new CheckDate(); 
     EventList = new EventList(); 

     manager = appWidgetManager; 
     views = new RemoteViews(context.getPackageName(), R.layout.widget_layout); 
     ids = appWidgetIds; 

     Intent intent = new Intent(context, DayWidget.class); 
     intent.setAction(EVENT_CLICK); 
     intent.putExtra("msg", "change"); 

     PendingIntent actionPendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0); 

     views.setOnClickPendingIntent(R.id.Event, actionPendingIntent); 

     CheckDate.Check(); 

     views.setTextViewText(R.id.Today, CheckDate.Today); 

     manager.updateAppWidget(ids, views); 
    } 

    public void UpdateWidget(){ 
     Bundle extras = intnt.getExtras(); 
     if(extras!=null) { 
      AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(cntxt); 
      ComponentName AppWidget = new ComponentName(cntxt.getPackageName(), DayWidget.class.getName()); 
      int[] appWidgetIds = appWidgetManager.getAppWidgetIds(AppWidget); 
      views.setTextViewText(R.id.Event, "New text"); 

      onUpdate(cntxt, appWidgetManager, appWidgetIds); 
     } 
    } 

    public void onReceive(Context context, Intent intent){ 
     intnt = intent; 
     cntxt = context; 

     if(EVENT_CLICK.equals(intent.getAction())){ 
      try{ 
       msg = intent.getStringExtra("msg"); 
      }catch(NullPointerException e){ 
       e.printStackTrace(); 
      } 
      UpdateWidget(); 
      //Toast toast = Toast.makeText(cntxt, "TEST", Toast.LENGTH_LONG); 
      //toast.show(); 
     } 
     super.onReceive(context, intent); 
    } 
}`

清單

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.sunmille.day" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk 
    android:minSdkVersion="9" 
    android:targetSdkVersion="17" /> 

<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" > 

    <receiver 
     android:name="DayWidget"> 
     <intent-filter> 
      <action 
       android:name="android.appwidget.action.APPWIDGET_UPDATE" /> 
      <action 
       android:name="android.appwidget.action.ACTION_WIDGET_RECEIVER" /> 
     </intent-filter> 
     <meta-data 
      android:name="android.appwidget.provider" 
      android:resource="@xml/widget_data" /> 
    </receiver> 

</application>

的Widget數據

<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android" 
android:minWidth="294dp" 
android:minHeight="72dp" 
android:minResizeWidth="294dp" 
android:minResizeHeight="72dp" 
android:updatePeriodMillis="0" 
android:resizeMode="horizontal|vertical" 
android:initialLayout="@layout/widget_layout">

的Widget佈局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical" 
android:background="@drawable/widget_background" > 

    <LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:gravity="center" > 

    <TextView 
     android:id="@+id/TopText" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Cегодня " 
     android:textIsSelectable="false" 
     android:textColor="#000000" 
     android:textSize="20sp" 
     android:textAppearance="?android:attr/textAppearanceLarge" /> 

    <TextView 
     android:id="@+id/Today" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:textIsSelectable="false" 
     android:textColor="#000000" 
     android:textSize="20sp" 
     android:textAppearance="?android:attr/textAppearanceLarge" />  

</LinearLayout> 

    <TextView 
     android:id="@+id/Event" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:textIsSelectable="false" 
     android:textColor="#000000" 
     android:textSize="20sp" 
     android:text="Some event" 
     android:textAppearance="?android:attr/textAppearanceLarge" />

日誌：

03-29 14:10:15.954: E/AndroidRuntime(4552): java.lang.RuntimeException: Unable to start receiver com.sunmille.day.DayWidget: java.lang.NullPointerException 
03-29 14:10:15.954: E/AndroidRuntime(4552):  at com.sunmille.day.DayWidget.UpdateWidget(DayWidget.java:61) 
03-29 14:10:15.954: E/AndroidRuntime(4552):  at com.sunmille.day.DayWidget.onReceive(DayWidget.java:77)

正確的代碼：

public class DayWidget extends AppWidgetProvider { 

public static CheckDate CheckDate; 
public static EventList EventList; 

public static String EVENT_CLICK = "EventClick"; 
public String msg; 

public RemoteViews rviews; 
public AppWidgetManager manager; 
public Context cntxt; 
public Intent intnt; 
public int[] ids; 

public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds){ 
    super.onUpdate(context, appWidgetManager, appWidgetIds); 

    CheckDate = new CheckDate(); 
    EventList = new EventList(); 

    manager = appWidgetManager; 
    RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widget_layout); 
    ids = appWidgetIds; 

    Intent intent = new Intent(context, DayWidget.class); 
    intent.setAction(EVENT_CLICK); 
    intent.putExtra("msg", "change"); 

    PendingIntent actionPendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0); 

    views.setOnClickPendingIntent(R.id.Event, actionPendingIntent); 

    CheckDate.Check(); 

    views.setTextViewText(R.id.Today, CheckDate.Today); 

    manager.updateAppWidget(ids, views); 
} 

public void UpdateWidget(){ 
    Bundle extras = intnt.getExtras(); 
    if(extras!=null) { 
     AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(cntxt); 
     ComponentName AppWidget = new ComponentName(cntxt.getPackageName(), DayWidget.class.getName()); 
     int[] appWidgetIds = appWidgetManager.getAppWidgetIds(AppWidget); 

     rviews = new RemoteViews(AppWidget.getPackageName(), R.layout.widget_layout); 
     rviews.setTextViewText(R.id.Event, "New text"); 

     appWidgetManager.updateAppWidget(appWidgetIds, rviews); 
    } 
} 

public void onReceive(Context context, Intent intent){ 
    intnt = intent; 
    cntxt = context; 

    if(EVENT_CLICK.equals(intent.getAction())){ 
     try{ 
      msg = intent.getStringExtra("msg"); 
     }catch(NullPointerException e){ 
      e.printStackTrace(); 
     } 
     UpdateWidget(); 
     Toast toast = Toast.makeText(cntxt, "TEST", Toast.LENGTH_LONG); 
     toast.show(); 
    } 
    super.onReceive(context, intent); 
}

}

來源

2013-03-29 Sergey Nanovsky

PLZ還添加日誌與問題，如果應用程序崩潰點擊 –

添加日誌。我在三星galaxy s3 mini上測試它 –

DayWidget.java中的行號61是哪裏？ –

RemoteViews類型的可變views爲空。你可以在Logcat輸出中看到它。

來源

2013-03-29 12:23:16 WELLCZECH

謝謝）將主題代碼發佈到主題 –

android widget textview動態更新

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