我正在使用苹果的快速编程语言制作一个简单的侧滚动游戏，我想让我的角色在触摸屏幕的左半部分时向左移动，在触摸另一半时向右移动。我使用此代码完成了此操作：
for touch: AnyObject in touches {
let location = touch.locationInNode(self)
if location.x < CGRectGetMidX(self.frame){
character.position.x -= 30
} else if location.x > CGRectGetMidX(self.frame){
character.position.x += 30
} else {
println("jump")
}
}
但他在移动30 px后立即停止移动。我的问题是，有人可以解释如何让他继续移动，直到用户举起手指？
这是我的GameScene.swift文件：
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
let character = SKSpriteNode(texture: SKTexture(imageNamed: "character"))
override func didMoveToView(view: SKView) {
/* Setup your scene here */
//world
self.physicsWorld.gravity = CGVectorMake(0.0, -5.0)
//background
var background = SKSpriteNode(imageNamed: "background")
background.size.height = self.frame.size.height
background.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
self.addChild(background)
//character
character.position = CGPointMake(self.frame.size.width * 0.6, self.frame.size.height * 0.6)
character.setScale(0.015)
character.physicsBody = SKPhysicsBody(circleOfRadius: CGFloat(character.size.width / 2))
var charPos = character.position
character.physicsBody?.dynamic = true
self.addChild(character)
//platform 1
var platformTexture = SKTexture(imageNamed: "platform")
var platform = SKSpriteNode(texture: platformTexture)
platform.position = CGPointMake(self.frame.size.width * 0.6, CGRectGetMidY(self.frame))
platform.physicsBody = SKPhysicsBody(rectangleOfSize: platform.size)
platform.physicsBody?.dynamic = false
platform.setScale(0.25)
self.addChild(platform)
//platform 2
var platformTexture2 = SKTexture(imageNamed: "platform")
var platform2 = SKSpriteNode(texture: platformTexture2)
platform2.position = CGPointMake(self.frame.size.width * 0.4, self.frame.size.height * 0.3)
platform2.physicsBody = SKPhysicsBody(rectangleOfSize: platform2.size)
platform2.physicsBody?.dynamic = false
platform2.setScale(0.25)
self.addChild(platform2)
//platform main
var platformTexture3 = SKTexture(imageNamed: "platform")
var platform3 = SKSpriteNode(texture: platformTexture2)
platform3.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMinY(self.frame) + platform3.size.height / 3)
platform3.physicsBody = SKPhysicsBody(rectangleOfSize: platform3.size)
platform3.physicsBody?.dynamic = false
platform3.setScale(1)
platform3.size.width = platform3.size.width * CGFloat(2.0)
self.addChild(platform3)
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
/* Called when a touch begins */
func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
}
}
答案 0 :(得分：1)
你必须在每次更新时不断对力量施加力量：调用以便不停地移动它。您还可以应用脉冲以移动角色或使其跳跃。这是一个基于您的代码的示例，为您提供如何使用物理（或通过手动更改字符的速度矢量）移动字符的基本概念。查看评论以找出重要的内容。
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
let character = SKSpriteNode(texture: SKTexture(imageNamed: "pauseButton"))
//Boolean variable to store information about move signal (updated in touchesBegan and touchesEnded method)
var move = false
override func didMoveToView(view: SKView) {
/* Setup your scene here */
//world
self.physicsWorld.gravity = CGVectorMake(0.0, -5.0)
self.physicsWorld.contactDelegate = self; //don't forget to set contact delegate if you want to use contact detection and methods like didBeginContact and didEndContact
//background
//just a physical border so that character can't escape from us :)
self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
//character
character.position = CGPointMake(self.frame.size.width * 0.6, self.frame.size.height * 0.6)
character.setScale(0.415)
character.physicsBody = SKPhysicsBody(circleOfRadius: CGFloat(character.size.width / 2))
var charPos = character.position
character.physicsBody?.dynamic = true
self.addChild(character)
}
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
/* Called when a touch begins */
for touch: AnyObject in touches {
let location = touch.locationInNode(self)
//Hold finger at upper area to move character constantly to the right.
if location.y > 400{
//moving allowed, force is applied in update method. read the docs about applyImpulse and applyForce methods and the differences between those two.
move = true
}else{
if location.x < CGRectGetMidX(self.frame){
character.physicsBody?.applyImpulse(CGVector(dx: -30, dy: 0))
//tap somewhere above this to make character jump
if(location.y > 250) {
character.physicsBody?.applyImpulse(CGVector(dx: 0, dy: 50))
}
} else if location.x > CGRectGetMidX(self.frame){
character.physicsBody?.applyImpulse(CGVector(dx: 30, dy: 0))
//tap somewhere above this to make character jump
if(location.y > 250) {
character.physicsBody?.applyImpulse(CGVector(dx: 0, dy: 50))
}
}
}
}
}
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
move = false
//character.physicsBody?.velocity = CGVector(dx: 0, dy: 0) //you can make character to stop by manually setting its velocity vector to (0,0)
}
override func update(currentTime: CFTimeInterval) {
if(move){character.physicsBody?.applyForce(CGVector(dx: 30, dy: 0))}
//if(move){character.position = CGPoint(x: character.position.x+1, y:character.position.y)} //not recommended if you need physics simulation (eg. collisions)
}
}
请注意，您可以在每次更新调用中更改节点的位置，以达到您想要的效果，如下所示：
if(move){character.position = CGPoint(x: character.position.x+1, y:character.position.y)}
但是这样你就可以将节点从物理模拟中拉出来，你会遇到意想不到的结果。搜索关于这个主题的SO，有一些关于这一切的好帖子。
希望这有点帮助。