Android 游戏：从一组图像中一次将一个图像拖入屏幕

Question

我的屏幕底部堆叠了 5 张图片。我的游戏目的是拖动这些图像并在特定条件下将它们连接起来。（有点像拼图游戏）我使用了以下代码

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;
     }
}

此代码一次将所有图像移动到触摸的坐标。我的要求是一次拖动一个图像，而不是一次拖动所有图像。 Cocossharp API 和 Xamarin 中给出的教程和 Github 在我看来没有多大帮助。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

这里是创建两个精灵并允许您单独拖动它们的示例。

设计:

您需要检测哪个精灵被触摸，然后只移动那个精灵。
在 OnTouchesBegan 中保存被触摸的精灵
在 OnTouchesMoved 中移动当前触摸的精灵

备注：

OnTouchesBegan 为每个注册事件的精灵调用一次。所以如果20个精灵添加监听器，OnTouchesBegan事件被调用20次（除非被吞噬，见下文）
您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 "Swallowing" 触摸将停止任何剩余的排队呼叫。吞下去，就return真。

一旦找到感兴趣的 sprite，您 return 忠实于 "swallow" 触摸事件并阻止其余 sprite 回调。这可以节省 cpu 并更快地执行您的 OnTouchesMoved。系统在处理完 OnTouchesBegan 之前不会调用 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
    }
}

Answer 2

我按照这个 link TouchableSpriteTest 实现了我需要的功能（在 jaybers 的帮助下）

示例代码

protected override void AddedToScene ()
        {
            --------------------------
            --------------------------  
            // Register for touch events
        var touchListener = new CCEventListenerTouchOneByOne ();
        touchListener.IsSwallowTouches = true;
        touchListener.OnTouchBegan = OnTouchBegan;
        touchListener.OnTouchEnded = OnTouchesEnded;            
        touchListener.OnTouchMoved = HandleTouchesMoved;
        batterySprite.AddEventListener (touchListener);
        pressSwitchSprite.AddEventListener (touchListener.Copy ());
        wireSprite3.AddEventListener (touchListener.Copy ());
        lampSprite.AddEventListener (touchListener.Copy ());
        wireSprite2.AddEventListener (touchListener.Copy ());
         }

      bool OnTouchBegan (CCTouch touch, CCEvent touchEvent)
        {       
            var target = (CCSprite)touchEvent.CurrentTarget;

            var locationInNode = touch.Location;
            var s = target.ContentSize;
            CCRect rect = target.BoundingBoxTransformedToWorld;

            if (rect.ContainsPoint (locationInNode)) {              
                target.Opacity = 180;
                return true;
            }
            return false;
        }

        void HandleTouchesMoved (CCTouch touch, CCEvent touchEvent)
        {       

            var target = (CCSprite)touchEvent.CurrentTarget;
            CCPoint pt = touch.PreviousLocation + touch.Delta;
            target.Position = target.WorldToParentspace (pt);
        }

Android 游戏：从一组图像中一次将一个图像拖入屏幕

Android game : Drag one image at a time into screen from a group of images

android

xamarin

cocossharp