打飞机02-飞机的拖动手势

拖动.gif

给飞机添加一个拖动的手势

1.创建一个手势pan，添加与之关联的动作panAction
2.添加手势pan到view

-(void)didMoveToView:(SKView *)view {

self.size = self.view.frame.size;

[self backgroundNode];
[self planeNode];

//创建一个手势与panAction关联
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panAction:)];

//添加手势到view
[self.view addGestureRecognizer:pan];

}

一、首先判断手指按下的是否是飞机

//这里需要设置一个全局变量
bool isPlane;

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    isPlane = NO;
    //获取手指按下的位置
    UITouch *touch = [touches anyObject];
    CGPoint  position = [touch locationInNode:self];

    //获取当前位置的精灵(如果有)
    SKNode *node = [self nodeAtPoint:position];

    //判断当前位置的精灵的name是否为plane
    if ([node.name isEqualToString:@"plane"]) {

        //全局变量isPlane设为YES;
        isPlane = YES;

    }

}

二、编写手势对应的动作

-(void)panAction:(UIGestureRecognizer *)sender {

    //判断isPlane是否为YES
    if (isPlane) {

        //获取plane精灵
        SKSpriteNode *plane = (SKSpriteNode *)[self childNodeWithName:@"plane"];

        //因为手势是添加到view上面的，获取传递进来view上面的手指拖动的坐标
        CGPoint position = [sender locationInView:sender.view];

        //view坐标(原点是左上角)和SpriteKit坐标(原点是左下角)之间的转换，x轴相同，y轴为与屏幕的height的差值
        position = CGPointMake(position.x, self.size.height -position.y);
        
        //根据手指位置改变plane位置
        plane.position = position;
    }
    
}