手指划动切换Activity

13年前
 以下代码用于Activity之间的划动切换，大概实现原理就是判断手指的划动速度和划动方向以确定向哪个Activity跳转，switchTo***Activity（）为Activity的跳转方法
private VelocityTracker velocityTracker;//用于得到手势在屏幕上的滑动速度  private static final int VELOCITY = 600;                 @Override  public boolean onTouchEvent(MotionEvent event) {   String localClassName = getLocalClassName();//当前所在类名   LogUtil.log(TAG, "class Name:"+localClassName);   int action = event.getAction();   //float x = event.getX();   //float y = event.getY();      switch (action) {   case MotionEvent.ACTION_DOWN:    if(velocityTracker == null){     velocityTracker = VelocityTracker.obtain();//取得手势在屏幕上的滑动速度     velocityTracker.addMovement(event);    }       //lastMotionX = x;        break;      case MotionEvent.ACTION_MOVE:    //int deltaX = (int) (lastMotionX - x);    if(velocityTracker != null){     velocityTracker.addMovement(event);    }    //lastMotionX = x;    break;       case MotionEvent.ACTION_UP:        int velocityX = 0;    if(velocityTracker != null){     velocityTracker.addMovement(event);     velocityTracker.computeCurrentVelocity(1000);//计算每秒滑动多少个像素     velocityX = (int) velocityTracker.getXVelocity();//最后计算检索X速度    }        if(velocityX > VELOCITY ){     if("ui.MainActivity".equals(localClassName)){      switchToTvLiveActivity();     }else if("ui.LocalMediaActivity".equals(localClassName)){      switchToMainActivity();     }else if("ui.NetMediaActivity".equals(localClassName)){      switchToLocalMediaActivity();     }else if("ui.TvLiveActivity".equals(localClassName)){      switchToNetMediaActivity();     }    } else if(velocityX < -VELOCITY ){     if("ui.MainActivity".equals(localClassName)){      switchToLocalMediaActivity();     }else if("ui.LocalMediaActivity".equals(localClassName)){      switchToNetMediaActivity();     }else if("ui.NetMediaActivity".equals(localClassName)){      switchToTvLiveActivity();     }else if("ui.TvLiveActivity".equals(localClassName)){      switchToMainActivity();     }    }        if(velocityTracker != null){     velocityTracker.recycle();//回收     velocityTracker = null;    }        break;   }      return true;  }