Question

我需要知道用户是否正在触摸精灵。我可以很容易地判断他是否举起手指或是否伸出手指：

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
        UITouch *touch = [touches anyObject];
        CGPoint location = [touch locationInNode:self];
        SKNode *node = [self nodeAtPoint:location];
        if ([node.name isEqualToString:@"button"]) {
             // Sprite stopped being touched
            return;
        }
}

然而，我对如何知道触摸是否结束感到无能为力，因为当用户将手指放在适当位置时精灵会移出。我想我应该以某种方式检查我的更新方法，但我不知道如何：

// Called before each frame is rendered
-(void)update:(CFTimeInterval)currentTime {
     // Check if the user is holding the sprite
}

如何做到这一点？

Answer 1

Apple提供有关他们提供的每个触摸事件的文档。您正在寻找的方法是touchesEnded

处理它与处理touchesMoved的方式相同，并调用您需要的任何方法，以通知节点它不再被触摸。

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint location = [touch locationInNode:self];
    SKNode *node = [self nodeAtPoint:location];
    if ([node.name isEqualToString:@"button"]) {
        // Notify the node that the touch has stopped
    }

}

Answer 2

我认为你要求下面这样的事情。有很多方法可以解决这个问题，但这是思考问题的基本方法。根据游戏的实际复杂程度，您可能需要进行一些状态检查以保护性能，但是您可以获得要点：

//in touchesBegan and touchesMoved update a property:
_lastTouchPoint = //the touch point in scene, etc, blah blah
//if you care about a specific sprite you could also store it:
_someMovingSprite = theSpriteIJustTouchedOrCareAbout;

//in update
if (CGRectContainsPoint(_someMovingSprite.frame, _lastTouchPoint)) {
    //the touch is inside the rect of the sprite
}
//OR

NSArray *spritesContainingTheTouchPoint = [self nodesAtPoint:_lastTouchPoint];

if (spritesContainingTheTouchPoint.count == 0) {
    //no sprites are being touched
}else{
    for (SKSpriteNode *spriteContainingTouch in spritesContainingTheTouchPoint) {
        //do something to sprite
    }
}



-(void)update:(CFTimeInterval)currentTime {
    CGPoint location = [_lastTouchPoint locationInNode:self];
    if (!CGRectContainsPoint(_sprite.frame, location)) {
        @NSLog(@"Sprite Released");
    }
}

如何知道精灵是否因为移动而停止被触摸？

2 个答案: