如何将Arraylist从Activity传递给Widget

时间:2013-08-23 14:04:29

标签: java android arraylist

我正在尝试将一个arraylist从活动传递给widget,但我的应用程序会破坏我的widget提供程序。

我在下面提供了详细信息。

以下是我第一次活动的部分代码:

        Intent intent1 = new Intent(MainActivity.this,
                AppProviderWidget.class);
        intent1.setAction("android.appwidget.action.APPWIDGET_UPDATE");
        // Use an array and EXTRA_APPWIDGET_IDS instead of
        // AppWidgetManager.EXTRA_APPWIDGET_ID,
        // since it seems the onUpdate() is only fired on that:
        int[] ids = widgetIDs;
        intent1.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, ids);
        intent1.putExtra("widgetlist", result);
        sendBroadcast(intent1);

我发送的数据在这里:

    intent1.putExtra("widgetlist", result);

来自AppProviderWidget onReceive方法的代码

    @Override
public void onReceive(Context context, Intent intent) {
    super.onReceive(context, intent);
    ArrayList<DuyuruHaber> arl = new ArrayList<DuyuruHaber>();
    arl = (ArrayList<DuyuruHaber>) intent
            .getSerializableExtra("widgetlist");

    try {

            liste = arl;
    } catch (Exception e) {
        Log.w("Log",e.toString());
    }}

AppProviderWidget.onReceive(AppProviderWidget.java:170)

arl = (ArrayList<DuyuruHaber>) intent
            .getSerializableExtra("widgetlist");

我的日志猫

08-23 16:28:01.684: E/AndroidRuntime(10067): FATAL EXCEPTION: main
08-23 16:28:01.684: E/AndroidRuntime(10067): java.lang.RuntimeException: Unable to start receiver widget.AppProviderWidget: java.lang.NullPointerException
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.app.ActivityThread.handleReceiver(ActivityThread.java:2821)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.app.ActivityThread.access$3200(ActivityThread.java:125)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2083)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.os.Handler.dispatchMessage(Handler.java:99)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.os.Looper.loop(Looper.java:123)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.app.ActivityThread.main(ActivityThread.java:4627)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at java.lang.reflect.Method.invokeNative(Native Method)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at java.lang.reflect.Method.invoke(Method.java:521)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at dalvik.system.NativeStart.main(Native Method)
08-23 16:28:01.684: E/AndroidRuntime(10067): Caused by: java.lang.NullPointerException
08-23 16:28:01.684: E/AndroidRuntime(10067):    at widget.AppProviderWidget.onReceive(AppProviderWidget.java:170)
08-23 16:28:01.684: E/AndroidRuntime(10067):    at android.app.ActivityThread.handleReceiver(ActivityThread.java:2810)

感谢您的帮助。

2 个答案:

答案 0 :(得分:0)

试试这个

intent.putParcelableArrayListExtra("myKey", ArrayList<T extends Parcelable> list);
startActivity(intent);

要检索它,您需要使用getIntent()方法

getIntent().getParcelableArrayListExtra("myKey");

答案 1 :(得分:0)

正如我在您的代码中看到的那样,您正在尝试传递DuyuruHaber对象的ArrayList。要传递自定义对象的列表,您的自定义对象(DuyuruHaber)必须实现“Serializable”接口。

您可以使用另一种简单方法使用静态方法传递DuyuruHaber对象的ArrayList。

在AppProviderWidget类中创建方法

private static ArrayList<DuyuruHaber> widgetList;

public static void setDuyuruHaberList(ArrayList<DuyuruHaber> data){
 AppProviderWidget.widgetList = data;
}

来自您的活动

在致电意图之前

AppProviderWidget.setDuyuruHaberList(result);