Android手机悬浮窗口小案例

//布局中就一个Buttonpublic class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {   @Override   public void onClick(View view) {   //目的就是启动Service来打开悬浮窗体    startService(new Intent(MainActivity.this, FloatService.class));    finish();   }  }); }}

/** * description：通过Service来开启FloatView * 作者：ldm * 时间：20162016/8/17 14:03 * 邮箱：1786911211@qq.com */public class FloatService extends Service { @Override public void onCreate() {  super.onCreate();  CustomViewManager.getInstance(this).showFloatViewOnWindow(); } @Override public IBinder onBind(Intent intent) {  return null; }}

/** * description： * 作者：ldm * 时间：20162016/8/17 11:57 * 邮箱：1786911211@qq.com */public class CustomViewManager { //上下文 private Context mContext; //本类实例 private static CustomViewManager instance; //自定义的FloatView private FloatView mFloatView; //窗口管理类 private WindowManager mWindowManager; private CustomViewManager(Context context) {  this.mContext = context;  mFloatView = new FloatView(mContext);  mWindowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE); } /**  * @param  * @description 通过单例模式获取实例对象  * @author ldm  * @time 2016/8/17 11:59  */ public static CustomViewManager getInstance(Context mContext) {  if (null == instance) {   synchronized (CustomViewManager.class) {    if (null == instance) {     instance = new CustomViewManager(mContext);    }   }  }  return instance; } /**  * @param  * @description 在手机屏幕上显示自定义的FloatView  * @author ldm  * @time 2016/8/17 13:47  */ public void showFloatViewOnWindow() {  WindowManager.LayoutParams parmas = new WindowManager.LayoutParams();  parmas.width = mFloatView.getFloatWidth();  parmas.height = mFloatView.getFloatHeight();  //窗口图案放置位置  parmas.gravity = Gravity.LEFT | Gravity.CENTER;  // 如果忽略gravity属性，那么它表示窗口的绝对X位置。  parmas.x = 0;  //如果忽略gravity属性，那么它表示窗口的绝对Y位置。  parmas.y = 0;  ////电话窗口。它用于电话交互（特别是呼入）。它置于所有应用程序之上，状态栏之下。  parmas.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;  //FLAG_NOT_FOCUSABLE让window不能获得焦点，这样用户快就不能向该window发送按键事件及按钮事件  //FLAG_NOT_TOUCH_MODAL即使在该window在可获得焦点情况下，仍然把该window之外的任何event发送到该window之后的其他window.  parmas.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;  // 期望的位图格式。默认为不透明。参考android.graphics.PixelFormat。  parmas.format = PixelFormat.RGBA_8888;  mWindowManager.addView(mFloatView, parmas); }}

/** * description： * 作者：ldm * 时间：20162016/8/17 11:17 * 邮箱：1786911211@qq.com */public class FloatView extends View { //悬浮球宽度 private int floatWidth = 150; //悬浮球高度 private int floatHeight = 150; //悬浮球画笔 private Paint mPaint; //绘制文字画笔 private Paint mTextPaint; private String text = "50%"; public FloatView(Context context) {  super(context);  initPaint(); } public int getFloatWidth() {  return floatWidth; } public int getFloatHeight() {  return floatHeight; } public FloatView(Context context, AttributeSet attrs) {  super(context, attrs);  initPaint(); } public FloatView(Context context, AttributeSet attrs, int defStyleAttr) {  super(context, attrs, defStyleAttr);  initPaint(); } /**  * @param  * @description 初始化画笔  * @author ldm  * @time 2016/8/17 11:37  */ private void initPaint() {  //设置悬浮球画笔  mPaint = new Paint();  mPaint.setColor(Color.GREEN);  mPaint.setAntiAlias(true);  mPaint.setDither(true);  //设置文字画笔  mTextPaint = new Paint();  mTextPaint.setTextSize(25);  mPaint.setAntiAlias(true);  mTextPaint.setColor(Color.WHITE);  mTextPaint.setFakeBoldText(true); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  //设置大小  setMeasuredDimension(floatWidth, floatHeight); } /**  * @param  * @description 绘制图案  * @author ldm  * @time 2016/8/17 11:44  */ @Override protected void onDraw(Canvas canvas) {  super.onDraw(canvas);  //绘制悬浮球  canvas.drawCircle(floatWidth / 2, floatHeight / 2, floatWidth / 2, mPaint);  //绘制文字  Paint.FontMetrics metrics = mTextPaint.getFontMetrics();  //文字大小计算可以参考：http://mikewang.blog.51cto.com/3826268/871765/  float textWidth = mTextPaint.measureText(text);  float x = floatWidth / 2 - textWidth / 2;  float dy = -(metrics.descent + metrics.ascent) / 2;  float y = floatHeight / 2 + dy;  canvas.drawText(text, x, y, mTextPaint); }}

 <!--添加权限--> <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

 <service android:name=".service.FloatService" />