Android开发模仿qq视频通话悬浮按钮(实例代码)

public class FloatingWindowService extends Service{
  private static final String TAG="OnTouchListener";
  private static View mView = null;
  private static WindowManager mWindowManager = null;
  private static Context mContext = null;
  public static Boolean isShown = false;
  public WindowManager.LayoutParams params = null;
  private int pixel;
  private int TheOffset;
  @Override
  public void onCreate() {
    super.onCreate();
  }
  @Override
  public int onStartCommand(Intent intent, int flags, int startId) {
    pixel = intent.getIntExtra("pixel",1);
    showPopupWindow(this);
    return super.onStartCommand(intent, flags, startId);
  }
  /**
   * 显示弹出框
   *
   * @param context
   *
   */
  private void showPopupWindow(final Context context) {
    if (isShown) {
      return;
    }
    isShown = true;
    // 获取应用的Context
    mContext = context.getApplicationContext();
    // 获取WindowManager
    mWindowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
    params = new WindowManager.LayoutParams();
    mView = setUpView(context);
    // 类型
    params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
    int flags=WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
    params.flags = flags;
    params.format = PixelFormat.TRANSLUCENT;
    params.width = WindowManager.LayoutParams.WRAP_CONTENT;
    params.height = WindowManager.LayoutParams.WRAP_CONTENT;
    params.gravity = Gravity.CENTER;
    mWindowManager.addView(mView, params);
  }
  /**
   * 隐藏弹出框
   */
  private static void hidePopupWindow() {
    if (isShown && null != mView) {
      mWindowManager.removeView(mView);
      isShown = false;
    }
  }
  private  int x=0;
  private  int y=0;
  private  int startX=0;
  private  int startY=0;
  private View setUpView(final Context context) {
    View view = LayoutInflater.from(context).inflate(R.layout.popupwindow,
        null);
     TextView tv= (TextView) view.findViewById(R.id.title);
    int w = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);
    int h = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);
    tv.measure(w, h);
    TheOffset=(pixel-tv.getMeasuredWidth())/2-50;
    tv.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Intent intent =new Intent(context,MainActivity.class);
        context.startActivity(intent);
        // Toast.makeText(context,"点击事件",Toast.LENGTH_LONG).show();
      }
    });
    tv.setOnTouchListener(new View.OnTouchListener() {
      @Override
      public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()){
          case MotionEvent.ACTION_MOVE:
            int newX= (int) (event.getRawX()-x);
            int newY= (int) (event.getRawY()-y);
            params.x=newX+startX;
            params.y=newY+startY;
              mWindowManager.updateViewLayout(mView,params);
            break;
          case MotionEvent.ACTION_DOWN:
            x= (int) event.getRawX();
            y= (int) event.getRawY();
            break;
          case MotionEvent.ACTION_UP:
            if(params.x>=0){
              params.x=TheOffset;
              mWindowManager.updateViewLayout(mView,params);
            }
            if(params.x<=-0){
              params.x=-TheOffset;
              mWindowManager.updateViewLayout(mView,params);
            }
            Log.i(TAG,params.x+"");
            Log.i(TAG,params.y+"");
            //判断 从按住到抬起时候的移动距离， 如果如果移动距离大于20 那么就拦截事件，否则就不拦截事件，主要是处理点击事件的冲突
            if(Math.abs(startX-params.x)>20 ||Math.abs(startY-params.y)>20 ){
              //记录上一次的偏移量
              startX=params.x;
              startY=params.y;
              return true;
            }else {
              startX=params.x;
              startY=params.y;
              return false;
            }
        }
        return false;
      }
    });
    return view;
  }
  @Nullable
  @Override
  public IBinder onBind(Intent intent) {
    return null;
  }
  @Override
  public void onDestroy() {
    super.onDestroy();
    if (mView != null) {
      isShown=false;
      mWindowManager.removeView(mView);
    }
  }
  }

@Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      findViewById(R.id.open).setOnClickListener(this);
      findViewById(R.id.close).setOnClickListener(this);
    }

@Override
    public void onClick(View v) {
      switch (v.getId()){
        case R.id.open:
          //判断是否拥有悬浮权限
          //op 的值是 0 ~ 47，其中0代表粗略定位权限，1代表精确定位权限，24代表悬浮窗权限。（具体可以看看Android源码在android.app下就有个AppOpsManager类）
          if(utils.checkOp(this,24)==0) {
            Intent intent=new Intent(MainActivity.this, FloatingWindowService.class);
            intent.putExtra("pixel",utils.pixel(this)[0]);
            startService(intent);
          }else {
            //引导用户进入悬浮权限设置界面
            Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
                Uri.parse("package:" + getPackageName()));
            startActivityForResult(intent, 200);
          }
          break;
        case R.id.close:
          stopService(new Intent(MainActivity.this,FloatingWindowService.class));
          break;
      }
    }

public class utils {
      public static int checkOp(Context context, int op){
        final int version = Build.VERSION.SDK_INT;
        if (version >= 19){
          Object object = context.getSystemService("appops");
          Class c = object.getClass();
          try {
            Class[] cArg = new Class[3];
            cArg[0] = int.class;
            cArg[1] = int.class;
            cArg[2] = String.class;
            Method lMethod = c.getDeclaredMethod("checkOp", cArg);
            return (Integer) lMethod.invoke(object, op, Binder.getCallingUid(), context.getPackageName());
          } catch(NoSuchMethodException e) {
            e.printStackTrace();
          } catch (IllegalAccessException e) {
            e.printStackTrace();
          } catch (IllegalArgumentException e) {
            e.printStackTrace();
          } catch (InvocationTargetException e) {
            e.printStackTrace();
          }
        }
        return -1;
      }
      /**
       * 获取屏幕的宽高
       * @param context
       * @return
       */
      public static int[] pixel(Activity context){
        DisplayMetrics dm = new DisplayMetrics();
        context.getWindowManager().getDefaultDisplay().getMetrics(dm);
        return new int[]{dm.widthPixels,dm.heightPixels};
      }
    }

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical">
    <LinearLayout
      android:id="@+id/popup_window"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:background="@android:color/white"
      android:orientation="vertical" >
      <TextView
        android:background="@mipmap/ic_launcher"
        android:id="@+id/title"
        android:layout_width="50dp"
        android:layout_height="50dp"/>
      </LinearLayout>
  </LinearLayout>