Java 如何遍历对象的ArrayList来创建条件?
我试图让我的最后一个IF循环遍历其中的三个对象 在PinballTypeOne列表中,只有ArrayList中的这三个对象在碰到左侧墙后,才应将其以前的颜色更改为橙色。碰撞确实起作用,但对象一直在反弹,而没有被更改为橙色,因此我认为ArrayList是如何生成的,或者我是如何尝试迭代ArrayList的。没有编译错误Java 如何遍历对象的ArrayList来创建条件?,java,arraylist,bluej,Java,Arraylist,Bluej,我试图让我的最后一个IF循环遍历其中的三个对象 在PinballTypeOne列表中,只有ArrayList中的这三个对象在碰到左侧墙后,才应将其以前的颜色更改为橙色。碰撞确实起作用,但对象一直在反弹,而没有被更改为橙色,因此我认为ArrayList是如何生成的,或者我是如何尝试迭代ArrayList的。没有编译错误 public class PinballObject { private int currentXLocation; private int currentY
public class PinballObject
{
private int currentXLocation;
private int currentYLocation;
private int speedXTravel;
private int speedYTravel;
private Color colour;
private int radius;
private Machine machine;
private final int leftWallPosition;
private final int bottomWallPosition;
private final int topWallPosition;
private final int rightWallPosition;
private ArrayList<PinballObject> PinballTypeOneList = new ArrayList<PinballObject>();
/**
* Constructor for objects of class Pinball_Obj
*
* @param xPos the horizontal coordinate of the object
* @param yPos the vertical coordinate of the object
* @param xVel the horizontal speed of the object
* @param yVel the vertical speed of the object
* @param objectRadius the radius (in pixels) of the object
* @param objectColor the color of the object
* @param theMachine the machine this object is in
*/
public PinballObject(int xPos, int yPos, int xVel, int yVel, Color objectColor, int objectRadius, Machine theMachine)
{
currentXLocation = xPos;
currentYLocation = yPos;
speedXTravel = xVel;
speedYTravel = yVel;
colour = objectColor;
radius = objectRadius;
machine = theMachine;
leftWallPosition = machine.getLeftWall();
bottomWallPosition = machine.getBottomWall();
topWallPosition = machine.getTopWall();
rightWallPosition = machine.getRightWall();
}
public void makeType1()
{
PinballObject firstTypeOne = new PinballObject(50, 200, -5, 3, Color.RED, 10, machine);
PinballTypeOneList.add(firstTypeOne);
PinballObject secondTypeOne = new PinballObject(100, 300, 1, 2, Color.BLUE, 55, machine);
PinballTypeOneList.add(secondTypeOne);
PinballObject thirdTypeOne = new PinballObject(450, 125, -1, -1, Color.YELLOW, 40, machine);
PinballTypeOneList.add(thirdTypeOne);
}
/**
* Move this object according to its position and speed and redraw.
**/
public void move()
{
// remove from universe at the current position
machine.erase(this);
// compute new position
currentYLocation += speedYTravel;
currentXLocation += speedXTravel;
// check if it has hit the leftwall + change color to orange only for the objects IN the arraylist
if(currentXLocation <= (leftWallPosition + radius))
{
currentXLocation = leftWallPosition + radius;
speedXTravel = -speedXTravel;
if(this.equals(PinballTypeOneList)){
colour = Color.ORANGE;
}
// draw again at new position
machine.draw(this);
}
}
公共类pinbalobject
{
私有内部位置;
私人住宅;
私人int speedXTravel;
私人快速旅行;
私人色彩;
私有整数半径;
私人机器;
私人最终职位;
私人最终职位;
私人最终职位;
私人最终职位;
私有ArrayList PinballTypeOneList=新ArrayList();
/**
*Pinball_Obj类对象的构造函数
*
*@param xPos对象的水平坐标
*@param yPos对象的垂直坐标
*@param xVel对象的水平速度
*@param yVel对象的垂直速度
*@param objectRadius对象的半径(以像素为单位)
*@param objectColor对象的颜色
*@param机器此对象所在的机器
*/
公共Pinball对象(int xPos、int YPO、int xVel、int yVel、Color objectColor、int objectRadius、机器)
{
currentXLocation=xPos;
currentlocation=yPos;
speedXTravel=xVel;
speedYTravel=yVel;
颜色=对象颜色;
半径=对象半径;
机器=机器;
leftWallPosition=machine.getLeftWall();
bottomWallPosition=machine.getBottomWall();
topWallPosition=machine.getTopWall();
rightWallPosition=machine.getRightWall();
}
公共void makeType1()
{
PinballObject firstTypeOne=新PinballObject(50,200,-5,3,彩色,红色,10,机器);
PinballTypeOne列表。添加(第一个TypeOne);
PinballObject secondTypeOne=新的PinballObject(100300,1,2,彩色,蓝色,55,机器);
PinballTypeOne列表。添加(第二个TypeOne);
PinballObject thirdTypeOne=新PinballObject(450125,-1,-1,颜色为黄色,40,机器);
PinballTypeOne列表。添加(第三种类型);
}
/**
*根据其位置和速度移动此对象并重新绘制。
**/
公开作废动议()
{
//在当前位置从宇宙中移除
清除(这个);
//计算新位置
currentYLocation+=快速旅行;
currentXLocation+=speedXTravel;
//检查它是否击中了leftwall+仅将arraylist中的对象的颜色更改为橙色
如果(currentXLocation为您的功能移动,您应该这样做:
public void move()
{
machine.erase(this);
currentYLocation += speedYTravel;
currentXLocation += speedXTravel;
if(currentXLocation <= (leftWallPosition + radius))
{
currentXLocation = leftWallPosition + radius;
speedXTravel = -speedXTravel;
for(PinballObject po : PinballTypeOneList) { //Iterating through list of PinballObject's
if(this.equals(po)) { // If this PinballObject is in list
colour = Color.ORANGE; // Or use po.colour
}
}
machine.draw(this);
}
}
公共作废移动()
{
清除(这个);
currentYLocation+=快速旅行;
currentXLocation+=speedXTravel;
if(currentXLocation Yourif(this.equals(PinballTypeOneList))
将始终返回true。这意味着什么?这意味着反弹后它将始终是橙色的。这也意味着如果代码中有无用的。问题是它们根本不会变为橙色,如果我删除该条件,我可以使它们全部变为橙色,但我尝试做的是只让ArrayList中的对象变为橙色橙色。它们在碰撞后反弹为相同的颜色。正如我前面提到的,我想我可能对ArrayList是如何制作的或者我是如何尝试迭代ArrayList有问题,我要么是瞎的,要么就是看不见。首先,你有一个类pinbalObject
,它有一个构造函数和函数move()
和makeType1()
这个返回PinballObject
类,它不能等于PinballTypeOneList
它是PinballObject
的数组,所以你需要从数组中选择一个PinballObject
,并使用if
如果(this.equals(PinballTypeOneList))
返回始终为false。