Question

我正在使用以下代码让球落下，每当我点击它时它应该跳回来，因此我的touchesBegan方法中的应用冲动。然而，当我运行这个代码时，球开始下降但是当我点击它时，它会继续下降。我做错了什么？

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */
[ball.physicsBody applyImpulse:CGVectorMake(0, 8)];
}

-(void) addBall
{
SKShapeNode *ball;
ball = [SKShapeNode shapeNodeWithCircleOfRadius:30];
ball.strokeColor = [SKColor colorWithRed:114.0f/255.0f green:84.0f/255.0f blue:123.0f/255.0f alpha:1.0];
ball.fillColor = [SKColor colorWithRed:114.0f/255.0f green:84.0f/255.0f blue:123.0f/255.0f alpha:1.0];
ball.position = CGPointMake(self.size.width/2,self.size.height/2);

//add physics body
ball.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:30];


[self addChild:ball];
}

-(void)didMoveToView: (SKView *)view
{
self.backgroundColor = [UIColor colorWithRed:113.0f/255.0f green:255.0f/255.0f blue:248.0f/255.0f alpha:1.0];
//add phsyics body to the scene
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];

//change gravity
self.physicsWorld.gravity = CGVectorMake(0, -6);



[self addBall];
}

-(void)update:(CFTimeInterval)currentTime {
/* Called before each frame is rendered */
}

Answer 1

你的冲动值非常低。增加它或减少重力，试试这个代码是有效的。

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */
for (SKSpriteNode *node in self.children) {
    if ([node.name isEqualToString:@"ball"])
        [node.physicsBody applyImpulse:
         CGVectorMake(0, 100)];
         NSLog(@"tapped ball");
}
}

-(void)didMoveToView: (SKView *)view
{
self.backgroundColor = [UIColor colorWithRed:113.0f/255.0f green:255.0f/255.0f blue:248.0f/255.0f alpha:1.0];
//add phsyics body to the scene
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];

//change gravity
self.physicsWorld.gravity = CGVectorMake(0, -6);



[self addBall];
}

-(void) addBall {
    ball = [SKShapeNode shapeNodeWithCircleOfRadius:30];
    ball.fillColor = [SKColor colorWithRed:225.0f/255.0f green:76.0f/255.0f blue:76.0f/255.0f alpha:1.0];
    ball.strokeColor = [SKColor colorWithRed:225.0f/255.0f green:76.0f/255.0f blue:76.0f/255.0f alpha:1.0];
    ball.position = CGPointMake(self.size.height/2, self.size.width/2);
    ball.name = @"ball";
    ball.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:30];

    [self addChild:ball];
}

Answer 2

以下是用于应用冲动的代码。

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInNode:self];
SKNode *node = [self nodeAtPoint:location];

// if ball is tapped apply impulse
if ([node.name isEqualToString:@"ball"]) {
    [node.physicsBody applyImpulse:
     CGVectorMake(0, 80)];

    NSLog(@"ball pressed");
}
}


-(void) addBall
{
SKShapeNode *ball;
ball = [SKShapeNode shapeNodeWithCircleOfRadius:30];
ball.strokeColor = [SKColor colorWithRed:114.0f/255.0f green:84.0f/255.0f blue:123.0f/255.0f alpha:1.0];
ball.fillColor = [SKColor colorWithRed:114.0f/255.0f green:84.0f/255.0f blue:123.0f/255.0f alpha:1.0];
ball.position = CGPointMake(self.size.width/2,self.size.height/2);
ball.name = @"ball";
//add physics body
ball.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:30];

[self addChild:ball];
}

Answer 3

您在ball中创建并添加物理主体的addBall与您在touchesBegan中施加冲动的行为不同。在addBall中，它是一个局部变量。也许你的意思是把它变成一个属性？然后在两个地方将其称为self.ball。

申请冲动不起作用

3 个答案: