Android桌面小部件

小部件创建步骤

小部件布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:id="@+id/butt_click"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="小部件"/>
</LinearLayout>

小部件配置文件

在res-xml资源目录下创建配置文件widget_app.xml:

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:initialKeyguardLayout="@layout/widget"
    android:minHeight="84dp"
    android:minWidth="84dp"
    android:updatePeriodMillis="86400000">
</appwidget-provider>

小部件实现类

package io.github.grooters.fifth;
import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.RemoteViews;
import android.widget.Toast;
/**
 * Create by 李林浪 in 2018/12/16
 * Elegant Code...
 */
public class AppWidgetProvider extends android.appwidget.AppWidgetProvider {
    private final String CLICK_ACTION="click";
    private final String TAG="AppWidgetProvider_debug";
    @Override
    public void onReceive(Context context, Intent intent) {
        super.onReceive(context, intent);
        Log.d(TAG,"onReceive");
        if(intent.getAction().equals(CLICK_ACTION)){
            Log.d(TAG,"intent.getAction().equals(CLICK_ACTION)");
            Toast.makeText(context,"你点击了小部件",Toast.LENGTH_SHORT).show();
        }
    }
    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        super.onUpdate(context, appWidgetManager, appWidgetIds);
        Log.d(TAG,"onUpdate");
        for (int appWidgetId:appWidgetIds){
            updateWidget(context,appWidgetManager,appWidgetId);
        }
    }
    private void updateWidget(Context context,AppWidgetManager manager,int appWidgetId){
        Log.d(TAG,"updateWidget");
        RemoteViews remoteViews=new RemoteViews(context.getPackageName(),R.layout.widget);
        Intent intent=new Intent();
        intent.setAction(CLICK_ACTION);
        intent.setClass(context,AppWidgetProvider.class);
        PendingIntent pendingIntent=PendingIntent.getBroadcast(context,0,intent,0);
        remoteViews.setOnClickPendingIntent(R.id.butt_click,pendingIntent);
        manager.updateAppWidget(appWidgetId,remoteViews);
    }
}

intent.setClass(context,AppWidgetProvider.class);必须要有，否则无法接收到该广播

声明小部件

<receiver android:name=".AppWidgetProvider">
    <meta-data
        android:name="android.appwidget.provider"
        android:resource="@xml/widget_app"/>
    <intent-filter>
        <action android:name="click" />
        <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
    </intent-filter>
</receiver>

action android:name=”click” 是自己定义的点击动作
action android:name=”android.appwidget.action.APPWIDGET_UPDATE”是指定该receiver为小部件

AppWidgetProvider

onEnable

当小部件第一次添加到桌面时会调用该方法

onUpdate

小部件被添加时或者每次更新时都会调用该方法

onDeleted

每删除一次桌面小部件就调用一次该方法

onDisabled

当最后一个该类型的桌面小部件被删除时调用该方法