Android小部件Widget開發過程中的坑和總結

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目錄

• 概述
  • 官方參考
  • 效果圖
• AndroidManifest.xml
  • Receiver
  • Service
• Options
  • res/xml/
    • widget_desktop_options.xml
  • 常用引數
    • Size
    • updatePeriodMillis
    • initialLayout
• Using App Widgets with Collections
  • 官方參考
  • AppWidgetProvider
  • RemoteViewsService
  • RemoteViewsFactory
  • DesktopActivity

概述

官方參考

Build an App Widget

效果圖

放張效果圖，這是我玩的桌面 app 資料夾

AndroidManifest.xml

Receiver

切記裡面的字母不要弄錯，最好複製貼上再修改相對應自定義的地方就好，一個字母的錯誤搞了我一天，吐血

<receiver android:name=".desktop.DesktopWidget">
    <meta-data
        android:name="android.appwidget.provider"
        android:resource="@xml/widget_desktop_options" />
    <intent-filter>
        <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
    </intent-filter>
</receiver>

Service

如果小部件中使用到了列表項如 ListView，GridView 等，在繫結資料時需要使用 RemoteViewsService 並提供一個 RemoteViewsFactory 例項來填充資料 而非 Adapter
再提，這裡面一定不能敲錯字母，特別是那個 permission 也一定要有，不然無法繫結資料

<service
    android:name=".desktop.DesktopViewsService"
    android:permission="android.permission.BIND_REMOTEVIEWS" />

Options

res/xml/

widget_desktop_options.xml

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="40dp"
    android:minHeight="40dp"
    android:initialLayout="@layout/widget_desktop"
    android:resizeMode="horizontal|vertical"
    android:widgetCategory="home_screen">
</appwidget-provider>

常用引數

Size

• 尺寸大小最終以單元格資料來顯示，但定義時為 dp

• 單元格數轉換基本工式 size = 70 x cells - 30

• 如：1格 = 70 x 1 - 30 = 40dp

• 最小尺寸定義時最好不要超過 4 個單元格就是 250dp

updatePeriodMillis

更新時間毫秒數，即間隔多少時間呼叫一次 onUpdate() 方法

initialLayout

載入佈局檔案

Using App Widgets with Collections

小部件中使用列表項

官方參考

Google Develper

AppWidgetProvider

public class DesktopWidget extends AppWidgetProvider {

    public String ACTION_START_ACTIVITY = "STARTACTIVITYACTION";

    public DesktopWidget() {
        super();
    }

    //當接收到廣播的時候會被呼叫
    //onUpdate, onEnabled等時都會傳送廣播
    @Override
    public void onReceive(Context context, Intent intent) {
        super.onReceive(context, intent);
        pub.log("onReceive:" + intent.getAction());
        if (intent.getAction().equals(ACTION_START_ACTIVITY)) {
            String strPackage = intent.getStringExtra("app_package");
            Intent appIntent = context.getPackageManager().getLaunchIntentForPackage(strPackage);
            pub.log(appIntent.getPackage());
            if (appIntent != null) {
                appIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                pub.log("start activity");
                context.startActivity(appIntent);
                pub.log("finish");
            }
        }
    }

    //被新增或者被更新時呼叫
    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        super.onUpdate(context, appWidgetManager, appWidgetIds);

        // There may be multiple widgets active, so update all of them
        for (int appWidgetId : appWidgetIds) {
            updateAppWidget(context, appWidgetManager, appWidgetId);
        }
    }
    private void updateAppWidget(Context context, AppWidgetManager appWidgetManager, int appWidgetId) {
        pub.log("onUpdate:" + appWidgetId);
        // Construct the RemoteViews object
        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widget_desktop);
        //設定小部件上 TextView 值
        //views.setTextViewText(R.id.tv_widget_desktop_title, "ZGTools");
        //setRemoteAdapter設定Listivew,Gridview等複雜佈局的adapter
        //第一個引數為要繫結的widget的Gridview的id，第二個引數為RemoteViewsService的intent
        Intent intent = new Intent(context, DesktopViewsService.class);
        intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
        views.setRemoteAdapter(R.id.gv_app_group, intent);

        //繫結 item 的定點事件
        //Activity方式測試不成功，改用廣播的方式進行傳送並執行事件
        //此處不能是空的Intent 否則廣播無法傳送
        //定義Intent事件模板，相當於公用設定，再在fillIntent裡面設定具體的 extra 值
        Intent templateIntent = new Intent(context, DesktopWidget.class);
        templateIntent.setAction(ACTION_START_ACTIVITY);
        templateIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        templateIntent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, appWidgetId, templateIntent, PendingIntent.FLAG_UPDATE_CURRENT);
        views.setPendingIntentTemplate(R.id.gv_app_group, pendingIntent);

        // Instruct the widget manager to update the widget
        appWidgetManager.updateAppWidget(appWidgetId, views);
    }


    //被新增或者更改大小時呼叫，在這個方法中可以選擇性的根據介面大小顯示或隱藏某些控制元件
    @Override
    public void onAppWidgetOptionsChanged(Context context, AppWidgetManager appWidgetManager, int appWidgetId, Bundle newOptions) {
        super.onAppWidgetOptionsChanged(context, appWidgetManager, appWidgetId, newOptions);
        updateAppWidget(context, appWidgetManager, appWidgetId);
    }
    @Override
    public void onEnabled(Context context) {
        super.onEnabled(context);
        // Enter relevant functionality for when the first widget is created
    }
    @Override
    public void onDisabled(Context context) {
        super.onDisabled(context);
        // Enter relevant functionality for when the last widget is disabled
    }
}

RemoteViewsService

public class DesktopViewsService extends RemoteViewsService {
    @Override
    public RemoteViewsFactory onGetViewFactory(Intent intent) {
        return new DesktopViewsFactory(this, intent);
    }
}

RemoteViewsFactory

型別於 BaseAdapter，重點是 onCreate() 載入資料， getViewAt() 方法返回佈局繫結資料

public class DesktopViewsFactory implements RemoteViewsService.RemoteViewsFactory {
    private Context mContext;
    private int mAppWidgetId;
    private List<AppPackage> lstApps = new ArrayList<AppPackage>();

    public DesktopViewsFactory(Context context, Intent intent){
        this.mContext = context;
        this.mAppWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
    }

    @Override
    public void onCreate() {
        DesktopDbHelper dbHelper = new DesktopDbHelper(mContext);
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String strSql = "Select * from tb_app";
        try {
            Cursor cursor = db.rawQuery(strSql, null);
            if (cursor != null && cursor.getCount() > 0) {
            	lstApps.clear();
                while (cursor.moveToNext()) {
                    byte[] blob = cursor.getBlob(cursor.getColumnIndex("app_icon"));
                    Bitmap bmpIcon = BitmapFactory.decodeByteArray(blob, 0, blob.length);
                    String strLabel = cursor.getString(cursor.getColumnIndex("app_label"));
                    String strPackage = cursor.getString(cursor.getColumnIndex("app_package"));
                    lstApps.add(new AppPackage(strLabel, strPackage, bmpIcon));
                }
            }
            if (cursor != null) {
                cursor.close();
            }
        } catch (Exception e) {
            db.close();
            e.printStackTrace();
        }
        db.close();
    }

    @Override
    public void onDataSetChanged() {
    	//這裡我加了重新載入資料的呼叫，用於更新小部件的列表內容
		onCreate();
	}
    @Override
    public void onDestroy() {}
    @Override
    public int getCount() {return 0;}

    @Override
    public RemoteViews getViewAt(int i) {
        if (i < 0 || i >= lstApps.size()) return null;
        //Construct a remote views item based on the app widget item XML file
        RemoteViews views = new RemoteViews(mContext.getPackageName(), R.layout.widget_desktop_item);
        views.setTextViewText(R.id.tv_widget_desktop_label, lstApps.get(i).getAppLabel());
        views.setImageViewBitmap(R.id.iv_widget_desktop_icon, lstApps.get(i).getAppIcon());

        Intent intent = new Intent();
        Bundle bundle = new Bundle();
        bundle.putString("app_package", lstApps.get(i).getAppPackage());
        intent.putExtras(bundle);
        views.setOnClickFillInIntent(R.id.iv_widget_desktop_icon, intent);
        views.setOnClickFillInIntent(R.id.tv_widget_desktop_label, intent);

        return views;
    }

    @Override
    public RemoteViews getLoadingView() { return null;}
    @Override
    public int getViewTypeCount() {return 0;}
    @Override
    public long getItemId(int i) { return 0;}
    @Override
    public boolean hasStableIds() { return false; }
}

DesktopActivity

    //更新widget佈局
    private void updateWidget(){
        AppWidgetManager widgetManager = AppWidgetManager.getInstance(this);
        ComponentName componentName = new ComponentName(this, DesktopWidget.class);
        int[] ids = widgetManager.getAppWidgetIds(componentName);
        widgetManager.notifyAppWidgetViewDataChanged(ids, R.id.gv_app_group);
    }