模仿苹果虚拟悬浮按钮（自动靠边、可浮现任何界面上）

  由于最近小蔡的手机音量键坏了，调节音量有点麻烦，突发奇想，想自己实现一个快捷键来调节音量。在忘上参考了一些代码，总结出一般本章，分享给大家。

首先 按钮要想实现悬浮在任何界面，那么必须是要写在服务里面的，使用定时器，2.5s不触摸后，背景变淡



下载地址

清单文件中加权限

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

public class FloatViewService extends Service {

private static final String TAG = "FloatViewService";
// 定义浮动窗口布局
private LinearLayout mFloatLayout;
private WindowManager.LayoutParams wmParams;
// 创建浮动窗口设置布局参数的对象
private WindowManager mWindowManager;

private ImageButton mFloatView;
private int screenHeight;
private int screenWidth;
private MyCountDownTimer myCountDownTimer;

@Override
public void onCreate() {
super.onCreate();
Log.i(TAG, "onCreate");
screenHeight = ScreenParam.getInstance().height;//自己写的工具类用来获取屏幕宽高。
screenWidth = ScreenParam.getInstance().width;
createFloatView();
myCountDownTimer = new MyCountDownTimer(2500, 1000); //设置计时2.5s
myCountDownTimer.start();
}

@SuppressWarnings("static-access")
@SuppressLint("InflateParams")
private void createFloatView() {
wmParams = new WindowManager.LayoutParams();
// 通过getApplication获取的是WindowManagerImpl.CompatModeWrapper
mWindowManager = (WindowManager) getApplication().getSystemService(
getApplication().WINDOW_SERVICE);
// 设置window type
wmParams.type = LayoutParams.TYPE_PHONE;
// 设置图片格式，效果为背景透明
wmParams.format = PixelFormat.RGBA_8888;
// 设置浮动窗口不可聚焦（实现操作除浮动窗口外的其他可见窗口的操作）
wmParams.flags = LayoutParams.FLAG_NOT_FOCUSABLE;
// 调整悬浮窗显示的停靠位置为右侧底部
wmParams.gravity = Gravity.RIGHT | Gravity.BOTTOM;
// 以屏幕左上角为原点，设置x、y初始值，相对于gravity
wmParams.x = 0;
wmParams.y = 150;
// 设置悬浮窗口长宽数据
wmParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
wmParams.height = WindowManager.LayoutParams.WRAP_CONTENT;

LayoutInflater inflater = LayoutInflater.from(getApplication());
// 获取浮动窗口视图所在布局
mFloatLayout = (LinearLayout) inflater.inflate(
R.layout.alert_window_menu, null);
// 添加mFloatLayout
mWindowManager.addView(mFloatLayout, wmParams);
// 浮动窗口按钮
mFloatView = (ImageButton) mFloatLayout
.findViewById(R.id.alert_window_imagebtn);

mFloatLayout.measure(View.MeasureSpec.makeMeasureSpec(0,
View.MeasureSpec.UNSPECIFIED), View.MeasureSpec
.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));

// 设置监听浮动窗口的触摸移动
mFloatView.setOnTouchListener(new OnTouchListener() {

boolean isClick;
private int leftDistance;
private float rawX;
private float rawY;

@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mFloatLayout.setAlpha(1.0f);
myCountDownTimer.cancel();取消计时

rawX = event.getRawX();
rawY = event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
// getRawX是触摸位置相对于屏幕的坐标，getX是相对于按钮的坐标
int distanceX = (int) (event.getRawX()-rawX);
int distanceY = (int) (event.getRawY()-rawY);
leftDistance = (int) event.getRawX()
+ mFloatView.getMeasuredWidth() / 2;

wmParams.x = wmParams.x-distanceX;
wmParams.y = wmParams.y-distanceY;
// 刷新
mWindowManager.updateViewLayout(mFloatLayout, wmParams);
rawX = event.getRawX();
rawY = event.getRawY();
break;
case MotionEvent.ACTION_UP:

myCountDownTimer.start();重新开始计时
if(wmParams.x>leftDistance){
wmParams.x = screenWidth-mFloatView.getMeasuredWidth() / 2;
}else{
wmParams.x = 0;
}
mWindowManager.updateViewLayout(mFloatLayout, wmParams);
break;
}
return false;
}
});

mFloatView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
AudioManager audioManager = (AudioManager) getSystemService(Service.AUDIO_SERVICE);
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
audioManager.getStreamVolume(AudioManager.STREAM_MUSIC), AudioManager.FLAG_SHOW_UI);
//				Toast.makeText(FloatViewService.this, "hello!",
//						Toast.LENGTH_SHORT).show();
}
});
}

@Override
public void onDestroy() {
super.onDestroy();
if (mFloatLayout != null) {
// 移除悬浮窗口
mWindowManager.removeView(mFloatLayout);
}
}

@Override
public IBinder onBind(Intent intent) {
return null;
}

public class MyCountDownTimer extends CountDownTimer {

public MyCountDownTimer(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}

@Override
public void onTick(long millisUntilFinished) {
}

@Override
public void onFinish() {
mFloatLayout.setAlpha(0.4f);
}
}

}

然后再Activity里启动服务就好了

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ScreenParam.getInstance().init(this);
}

@Override
protected void onStart() {
// TODO Auto-generated method stub
Intent intent = new Intent(MainActivity.this, FloatViewService.class);
//启动FloatViewService
startService(intent);
super.onStart();
}

如果不想显示Activity界面的话，可以在配置这个属性就ok了

android:theme="@android:style/Theme.NoDisplay"

android:theme="@android:style/Theme.NoDisplay"

就是这么简单！