java - Android Widget - 单击按钮时更新

Question

美好的一天。我正在尝试创建一个将在屏幕上显示余额的小部件。创建了 2 个按钮并设置监听器以确定按下了哪个按钮。

难度:如何通过点击按钮或重新加载小部件来更新数据以便更新数据？

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.RemoteViews;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.text.DateFormat;
import java.util.Date;

public class EthWidgetProvider extends AppWidgetProvider {
    private static final String SYNC_CLICKED    = "automaticWidgetSyncButtonClick";
    private static final String SYNC_CLICKED2    = "automaticWidgetSyncButtonClick2";


    static void updateAppWidget(final Context context, final AppWidgetManager appWidgetManager, final int appWidgetId) {
        RequestSingleton.getInstance(context).fetchData(new VolleyCallback() {
            @Override
            public void onSuccessRequest(JSONArray result) {
                Log.i("Response", result.toString());
                String price = "";
                try {
                    JSONObject etherObject = result.getJSONObject(0);
                    price = etherObject.getString("price_usd");
                } catch (JSONException e) {
                    Log.e("JSONException", e.toString());
                }
                Log.i("Price", price);
                RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.example_widget);
                views.setTextViewText(R.id.gprs, "$" + price);

                String currentDateTimeString = DateFormat.getDateTimeInstance().format(new Date());
                views.setTextViewText(R.id.timeofday, currentDateTimeString);

                appWidgetManager.updateAppWidget(appWidgetId, views);
            }
        });
    }
    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {


        RemoteViews remoteViews;
        ComponentName watchWidget;

        remoteViews = new RemoteViews(context.getPackageName(), R.layout.example_widget);
        watchWidget = new ComponentName(context, EthWidgetProvider.class);

        remoteViews.setOnClickPendingIntent(R.id.refresh, getPendingSelfIntent(context, SYNC_CLICKED));
        remoteViews.setOnClickPendingIntent(R.id.example_widget_button, getPendingSelfIntent(context, SYNC_CLICKED2));
        appWidgetManager.updateAppWidget(watchWidget, remoteViews);

        for(int appId : appWidgetIds) {
            updateAppWidget(context, appWidgetManager, appId);
        }
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        super.onReceive(context, intent);

        if (SYNC_CLICKED.equals(intent.getAction())) {

            AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);

            RemoteViews remoteViews;
            ComponentName watchWidget;

            remoteViews = new RemoteViews(context.getPackageName(), R.layout.example_widget);
            watchWidget = new ComponentName(context, EthWidgetProvider.class);

            remoteViews.setTextViewText(R.id.timeofday, "TESTING");

            appWidgetManager.updateAppWidget(watchWidget, remoteViews);

        }

        if (SYNC_CLICKED2.equals(intent.getAction())) {

            AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);

            RemoteViews remoteViews;
            ComponentName watchWidget;

            remoteViews = new RemoteViews(context.getPackageName(), R.layout.example_widget);
            watchWidget = new ComponentName(context, EthWidgetProvider.class);

            remoteViews.setTextViewText(R.id.timeofday, "TESTING2");

            appWidgetManager.updateAppWidget(watchWidget, remoteViews);

        }
    }

protected PendingIntent getPendingSelfIntent(Context context, String action) {
        Intent intent = new Intent(context, getClass());
        intent.setAction(action);
        return PendingIntent.getBroadcast(context, 0, intent, 0);
    }
}

按下按钮 1，我需要显示 Activity 。通过按下第二个按钮，您需要更新小部件以便更新数据，即再次向服务器发出请求并更新数据。

如有任何帮助，我们将不胜感激。

Answer 1

我不明白你对广播的看法。

1. 广播不应该是内部类
2. Broadcast 应该继承 BroadcastReceiver 类
3. 广播应该在 list 中定义

所以当你这样做时，你的接收器应该在点击按钮后被调用。

但是，您需要一些东西来唤醒您的 Widget。然后 Widget#onUpdate 将获取更新的数据(您在点击小部件时下载)并显示它们。要请求更新您的小部件，您可以使用如下内容:

public static void updateAppWidget(@NonNull Context applicationContext,
        @NonNull Class<? extends AppWidgetProvider> widgetProviderClass) {
    final ComponentName component = new ComponentName(applicationContext, widgetProviderClass);
    final int[] widgetIds;
    try {
        widgetIds = AppWidgetManager.getInstance(applicationContext).getAppWidgetIds(component);
    } catch (RuntimeException re) {
        Log.d(re, "Unable to obtain widget IDs.");
        return;
    }

    if (widgetIds.length == 0) {
        Log.d("There is no widget to be updated.");
        return;
    }

    final Intent intent = new Intent(applicationContext, widgetProviderClass);
    intent.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
    intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, widgetIds);

    applicationContext.sendBroadcast(intent);
}

总结一下:

• 在小部件设置 View 、监听器中，并填充最后已知的数据。
• 在监听广播中打开 Activity，或者运行一些下载
• 不要忘记 BroadcastReceivers 在 UI 线程上运行；使用goAsync() 方法。
• 下载的数据应该存储到某个地方，小部件可以在那里获得它们
• 调用提到的函数来触发小部件更新。

我相信，与 Android 的其他部分不同，这是一个非常具体和复杂的主题，所以请尽管问我可能遗漏的任何问题 :)