安卓桌面小部件開發 RemoteView 自定義桌面小部件 自定義小部件統共分幾步

RemoteView 自定義桌面小部件

效果如上圖, class AppWidgetProvider extends BroadcastReceiver,不難看出桌面小部件本質上是一個廣播,至於爲什麼是一個廣播的形勢,我猜...是因爲桌面小部件運行在SystemService進程中,通過PendingIntent這種方式傳遞,避免了自己寫IPC通信。

自定義小部件統共分幾步

1.定義小部件界面

在layout 下創建xml 文件

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageView
        android:id="@+id/tv_content"
        android:src="@mipmap/ic_launcher"
        android:gravity="center"
        android:textSize="20sp"
        android:layout_width="100dp"
        android:layout_height="100dp" />
</RelativeLayout>

2.定義小部件配置信息

通過as自帶的創建app widget功能會自動創建該文件,否則需要手動指定,定義小部件刷新,最小寬高等信息

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:initialKeyguardLayout="@layout/new_app_widget"
    android:initialLayout="@layout/new_app_widget"
    android:minHeight="110dp"
    android:minWidth="110dp"
    android:previewImage="@mipmap/ic_launcher"
    android:resizeMode="horizontal|vertical"
    android:updatePeriodMillis="86400000"
    android:widgetCategory="home_screen" />

• resizeMode 小部件可伸縮方向
• minHeight,minWidth 小部件最寬高
• previewImage 拖動到桌面前的預覽圖片
• nitialLayout初始化佈局
• updatePeriodMillis小部件的刷新間隔，單位是秒，默認是一天

3. 繼承AppWidgetProvider

public class NewAppWidget extends AppWidgetProvider {

    private static final String fs="com.example.admin.customview.click";

    static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
                                int appWidgetId) {

        RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget);
        Intent clickIntent = new Intent();

        clickIntent.setAction(fs);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, clickIntent, 0);
        remoteViews.setOnClickPendingIntent(R.id.tv_content,pendingIntent);

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

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        // There may be multiple widgets active, so update all of them
        for (int appWidgetId : appWidgetIds) {
            updateAppWidget(context, appWidgetManager, appWidgetId);
        }
    }
    @Override
    public void onEnabled(Context context) {
        // Enter relevant functionality for when the first widget is created
    }

    @Override
    public void onDisabled(Context context) {
        // Enter relevant functionality for when the last widget is disabled
    }

    @Override
    public void onReceive(final Context context, Intent intent) {
        super.onReceive(context, intent);
        Log.d("88888888888", "onReceive: ");

        String action = intent.getAction();
        final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.mipmap.ic_launcher);
        //判斷是否是自定義點擊action
        if (action.equals(fs)){
            Toast.makeText(context, "clicked it", Toast.LENGTH_SHORT).show();
            new Thread(new Runnable() {
                @Override
                public void run() {
                    AppWidgetManager manager = AppWidgetManager.getInstance(context);

                    for (int i = 0; i < 37; i++) {
                        RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget);
                        remoteViews.setImageViewBitmap(R.id.tv_content,rotateBitmap(bitmap,i*10));
                        Intent clickIntent = new Intent();
                        clickIntent.setAction(fs);
                        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, clickIntent, 0);
                        remoteViews.setOnClickPendingIntent(R.id.tv_content,pendingIntent);
                        Log.d("8888888", "run: ");
                        manager.updateAppWidget(new ComponentName(context,NewAppWidget.class),remoteViews);

                        SystemClock.sleep(30);

                    }
                }
            }).start();
        }
    }

    private Bitmap rotateBitmap(Bitmap bitmap,float degree) {
        Matrix matrix = new Matrix();
        matrix.reset();
        matrix.setRotate(degree);
        Bitmap bm = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);


        return bm;
    }
}

• onEnabled 當小部件第一次添加到桌面時調用
• onUpdate 當小部件被添加或者更新時調用
• onReceive 作爲一個廣播,當接接受到Intent消息的時候調用

4.在AndroidManifest 中聲明小部件

  <receiver android:name=".NewAppWidget">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
                <action android:name="com.example.admin.customview.click" />
            </intent-filter>

            <meta-data
                android:name="android.appwidget.provider"
                android:resource="@xml/new_app_widget_info" />
        </receiver>

第一個action 作爲小部件的標記存在,在安裝時系統讓系統檢測到包含小部件組件
第二個action 用於BrocastReceiver 接受點擊事件