public class MyAccessibilityService extends AccessibilityService {
 public static final int BACK = 1;
 public static final int HOME = 2;
 private static final String TAG = "ICE";

 @Override
 public void onCreate() {
 super.onCreate();
 //使用EventBus代替廣播
 EventBus.getDefault().register(this);
 }

 @Override
 public void onAccessibilityEvent(AccessibilityEvent event) { }

 @Override
 public void onInterrupt() {}

 @Subscribe
 public void onReceive(Integer action){
 switch (action){
 case BACK:
 performGlobalAction(AccessibilityService.GLOBAL_ACTION_BACK);
 break;
 case HOME:
 performGlobalAction(AccessibilityService.GLOBAL_ACTION_HOME);
 break;
 }
 }

}

<service
 android:name=".MyAccessibilityService"
 android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
 <intent-filter>
 <action android:name="android.accessibilityservice.AccessibilityService"/>
 </intent-filter>
 <meta-data
 android:name="android.accessibilityservice"
 android:resource="@xml/accessibilityservice"/>
</service>

<?xml version="1.0" encoding="utf-8"?>
<accessibility-service
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:description="@string/start_floatingBall"/>

<!--我這里寫(xiě)的是開(kāi)啟懸浮球功能-->

public class FloatingView extends View {

 public int height = 150;
 public int width = 150;
 private Paint paint;


 public FloatingView(Context context){
 super(context);
 paint = new Paint();
 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 setMeasuredDimension(height,width);
 }

 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 //畫(huà)大圓
 paint.setStyle(Paint.Style.FILL);
 paint.setAntiAlias(true);
 paint.setColor(getResources().getColor(R.color.state_one));
 canvas.drawCircle(width/2,width/2,width/2,paint);
 //畫(huà)小圓圈
 paint.setStyle(Paint.Style.STROKE);
 paint.setColor(Color.WHITE);
 canvas.drawCircle(width/2,width/2, (float) (width*1.0/4),paint);

 }

public class ViewManager {
 FloatingView floatBall;
 WindowManager windowManager;
 public static ViewManager manager;
 Context context;
 private WindowManager.LayoutParams floatBallParams;

 private ViewManager(Context context) {
 this.context = context;
 }

 public static ViewManager getInstance(Context context) {
 if (manager == null) {
 manager = new ViewManager(context);
 }
 return manager;
 }
 public void showFloatBall() {
 floatBall = new FloatingView(context);
 windowManager = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
 if (floatBallParams == null) {
 floatBallParams = new WindowManager.LayoutParams();
 floatBallParams.width = floatBall.width;
 floatBallParams.height = floatBall.height;
 floatBallParams.gravity = Gravity.TOP | Gravity.LEFT;
 floatBallParams.type = WindowManager.LayoutParams.TYPE_TOAST;
 floatBallParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;
 floatBallParams.format = PixelFormat.RGBA_8888;
 }

 windowManager.addView(floatBall, floatBallParams);

 floatBall.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 EventBus.getDefault().post(MyAccessibilityService.BACK);
 Toast.makeText(context, "點(diǎn)擊了懸浮球 執(zhí)行后退操作", Toast.LENGTH_SHORT).show();
 }
 });

 floatBall.setOnLongClickListener(new View.OnLongClickListener() {
 @Override
 public boolean onLongClick(View v) {
 EventBus.getDefault().post(MyAccessibilityService.HOME);
 Toast.makeText(context, "長(zhǎng)按了懸浮球 執(zhí)行返回桌面", Toast.LENGTH_SHORT).show();
 return false;
 }
 });

 }

 public int getScreenWidth() {
 return windowManager.getDefaultDisplay().getWidth();
 }

}

ViewManager.getInstance(MainActivity.this).showFloatBall();