Android游戏:将一个图像一次拖动到一组图像的屏幕中

Question

我的屏幕底部有5张图像.我的游戏的目的是拖动这些图像并在特定条件下连接它们.(排序拼图)我使用下面的代码

var touchListener = new CCEventListenerTouchAllAtOnce ();
touchListener.OnTouchesEnded = OnTouchesEnded;
touchListener.OnTouchesMoved = HandleTouchesMoved;
AddEventListener (touchListener, this);
void HandleTouchesMoved (List touches, CCEvent touchEvent)
{
    foreach(var tap in touches)
    {
       var locationOnScreen = tap.Location;
       alarmicSprite.PositionY = locationOnScreen.Y;
       alarmicSprite.PositionX = locationOnScreen.X;
       pressSwitchSprite.PositionY = locationOnScreen.Y;
       pressSwitchSprite.PositionX = locationOnScreen.X;
     }
}

此代码将所有图像一次移动到触摸的坐标.我的要求是一次拖动一个图像不同于一次.在我看来,Xamarin和Github中给出的Cocossharp API和教程没那么有用.有没有一种方法可以在一个触摸实例上拖动一个图像？帮助赞赏

Answer 1

下面是一个创建两个精灵的示例,您可以单独拖动它们.

设计:

• 您需要检测正在触摸的精灵,然后才移动该精灵.
• 保存OnTouchesBegan中触摸的精灵
• 在OnTouchesMoved中移动当前触摸的精灵

备注:

• 对于注册事件的每个精灵,都会调用一次OnTouchesBegan .因此,如果20个精灵添加了监听器,则OnTouchesBegan事件被调用20次(除非被吞下,见下文)
• 以编程方式确定触摸位置是否在调用OnTouchesBegan的精灵的边界框内.然而,"吞咽"触摸将停止任何剩余的排队呼叫.吞下去,就回归真.

• 一旦找到感兴趣的精灵,就会返回true以"吞下"触摸事件并停止其余的精灵回调.这样可以节省CPU并更快地执行OnTouchesMoved.在完成处理OnTouchesBegan之前,系统不会调用OnTouchesMoved.

  CCSprite currentSpriteTouched;
  CCSprite Sprite1;
  CCSprite Sprite2;
  protected override void AddedToScene()
  {
      base.AddedToScene();
  
      // Use the bounds to layout the positioning of our drawable assets
      CCRect bounds = VisibleBoundsWorldspace;
  
      Sprite1 = new CCSprite("redball.png");
      Sprite2 = new CCSprite("blueball.png");
  
      Sprite1.Position = bounds.Center;
      Sprite2.Position = bounds.Center;
      AddChild(Sprite1);
      AddChild(Sprite2);
  
      // Register for touch events
      var touchListener =  new CCEventListenerTouchOneByOne();
      touchListener.IsSwallowTouches = true;
      touchListener.OnTouchBegan = this.OnTouchesBegan;
      touchListener.OnTouchMoved = this.OnTouchesMoved;
  
      AddEventListener(touchListener, Sprite2);
      AddEventListener(touchListener.Copy(), Sprite1);
  
  }
  
  
  void OnTouchesMoved(CCTouch touch, CCEvent touchEvent)
  {
      if (currentSpriteTouched != null)
      {
          currentSpriteTouched.Position = touch.Location;
      }
  }
  
  bool OnTouchesBegan(CCTouch touch, CCEvent touchEvent)
  {
      // This is called once for each sprite
      // To stop the remaining sprites from calling, 
      //   "swallow" the touch by returning true
      CCSprite caller = touchEvent.CurrentTarget as CCSprite;
      currentSpriteTouched = null;
      if (caller == Sprite1)
      {
          if (Sprite1.BoundingBoxTransformedToWorld.ContainsPoint(touch.Location))
          {
              System.Diagnostics.Debug.WriteLine("Sprite 1 touched ");
              currentSpriteTouched = Sprite1;
              return true;  // swallow    
          }
          else
          {
              return false;  // do not swallow and try the next caller
          }
  
      }
      else if (caller == Sprite2)
      {
          if (Sprite2.BoundingBoxTransformedToWorld.ContainsPoint(touch.Location))
          {
              currentSpriteTouched = Sprite2;
              System.Diagnostics.Debug.WriteLine("Sprite 2 touched ");
              return true;  // swallow    
          }
          else
          {
              return false;  // do not swallow and try the next caller
          }
      }
      else
      {
          // something else touched
          System.Diagnostics.Debug.WriteLine("Something else was touched");
          return false;  // Do not swallow
      }
  }