android悬浮窗

• 首先需要申请权限

       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
              if (Settings.canDrawOverlays(MainActivity.this))
              {
                  Intent intent = new Intent(MainActivity.this,MainService.class);
                  Toast.makeText(MainActivity.this,"已开启Toucher",Toast.LENGTH_SHORT).show();
                  startService(intent);
                  finish();
              }else
              {
                  //若没有权限，提示获取.
                  Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
                  Toast.makeText(MainActivity.this,"需要取得权限以使用悬浮窗",Toast.LENGTH_SHORT).show();
                  startActivity(intent);
                  finish();
              }
          }else{
              Intent intent = new Intent(MainActivity.this, MainService.class);
              startService(intent);
              finish();
          }
  

  　　

• 开启一个service

  package com.lightingcontour.toucher;
  
  import android.app.Service;
  import android.content.Context;
  import android.content.Intent;
  import android.graphics.PixelFormat;
  import android.os.Handler;
  import android.os.IBinder;
  import android.os.SystemClock;
  import android.support.constraint.ConstraintLayout;
  import android.util.Log;
  import android.view.Gravity;
  import android.view.LayoutInflater;
  import android.view.MotionEvent;
  import android.view.View;
  import android.view.WindowManager;
  import android.widget.ImageButton;
  import android.widget.RelativeLayout;
  import android.widget.Toast;
  
  public class MainService extends Service {
  
      private static final String TAG = "MainService";
  
      ConstraintLayout toucherLayout;
      WindowManager.LayoutParams params;
      WindowManager windowManager;
  
      ImageButton imageButton1;
  
      //状态栏高度.
      int statusBarHeight = -1;
  
      //不与Activity进行绑定.
      @Override
      public IBinder onBind(Intent intent)
      {
          return null;
      }
  
      @Override
      public void onCreate()
      {
          super.onCreate();
          Log.i(TAG,"MainService Created");
          createToucher();
      }
  
      private void createToucher()
      {
          //赋值WindowManager&LayoutParam.
          params = new WindowManager.LayoutParams();
          windowManager = (WindowManager) getApplication().getSystemService(Context.WINDOW_SERVICE);
          //设置type.系统提示型窗口，一般都在应用程序窗口之上.
          params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
          //设置效果为背景透明.
          params.format = PixelFormat.RGBA_8888;
          //设置flags.不可聚焦及不可使用按钮对悬浮窗进行操控.
          params.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
  
          //设置窗口初始停靠位置.
          params.gravity = Gravity.LEFT | Gravity.TOP;
          params.x = 0;
          params.y = 0;
  
          //设置悬浮窗口长宽数据.
          params.width = 300;
          params.height = 300;
  
          LayoutInflater inflater = LayoutInflater.from(getApplication());
          //获取浮动窗口视图所在布局.
          toucherLayout = (ConstraintLayout) inflater.inflate(R.layout.toucherlayout,null);
          //添加toucherlayout
          windowManager.addView(toucherLayout,params);
  
          Log.i(TAG,"toucherlayout-->left:" + toucherLayout.getLeft());
          Log.i(TAG,"toucherlayout-->right:" + toucherLayout.getRight());
          Log.i(TAG,"toucherlayout-->top:" + toucherLayout.getTop());
          Log.i(TAG,"toucherlayout-->bottom:" + toucherLayout.getBottom());
  
          //主动计算出当前View的宽高信息.
          toucherLayout.measure(View.MeasureSpec.UNSPECIFIED,View.MeasureSpec.UNSPECIFIED);
  
          //用于检测状态栏高度.
          int resourceId = getResources().getIdentifier("status_bar_height","dimen","android");
          if (resourceId > 0)
          {
              statusBarHeight = getResources().getDimensionPixelSize(resourceId);
          }
          Log.i(TAG,"状态栏高度为:" + statusBarHeight);
  
          //浮动窗口按钮.
          imageButton1 = (ImageButton) toucherLayout.findViewById(R.id.imageButton1);
  
          imageButton1.setOnClickListener(new View.OnClickListener() {
              long[] hints = new long[2];
              @Override
              public void onClick(View v) {
                  Log.i(TAG,"点击了");
                  System.arraycopy(hints,1,hints,0,hints.length -1);
                  hints[hints.length -1] = SystemClock.uptimeMillis();
                  if (SystemClock.uptimeMillis() - hints[0] >= 700)
                  {
                      Log.i(TAG,"要执行");
                      Toast.makeText(MainService.this,"连续点击两次以退出",Toast.LENGTH_SHORT).show();
                  }else
                  {
                      Log.i(TAG,"即将关闭");
                      stopSelf();
                  }
              }
          });
  
          imageButton1.setOnTouchListener(new View.OnTouchListener() {
              @Override
              public boolean onTouch(View v, MotionEvent event) {
                  Log.i(TAG,"event:->"+event.getAction());
                  params.x = (int) event.getRawX() - 150;
                  params.y = (int) event.getRawY() - 150 - statusBarHeight;
                  windowManager.updateViewLayout(toucherLayout,params);
                  return false;
              }
          });
      }
  
      @Override
      public void onDestroy()
      {
          if (imageButton1 != null)
          {
              windowManager.removeView(toucherLayout);
          }
          super.onDestroy();
      }
  }
  

  　　
• 添加权限

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