java - 是否可以访问在方法内部创建的对象？

Question

我正在为我的游戏设计和开发类(class)制作期末项目。我有一种方法可以为角色创建类对象，并为代表敌人角色创建空间几何图形。

敌人角色已创建，但我无法访问在该方法中创建的对象(仅几何图形)。

这是创建敌人的方法:

/*
Method to create an enemy model.  
*/
protected Spatial makeEnemy(String t, float x, float y, float z) {

    Character emy = new Character(t);

    // load a character from jme3test-test-data
    Spatial enemy = assetManager.loadModel(emy.getLocation());
    if (t=="ogre") {
        enemy.scale(4.0f);
    } else {
        enemy.scale(1.0f);
    }

    enemy.setLocalTranslation(x, y, z);

    //add physics
    enemy_phy = new RigidBodyControl(2f);
    enemy.addControl(enemy_phy);
    bulletAppState.getPhysicsSpace().add(enemy_phy);

    //add a light to make the model visible
    DirectionalLight sun = new DirectionalLight();
    sun.setDirection(new Vector3f(-0.1f, -0.7f, 1.0f));
    enemy.addLight(sun);
    enemy.rotate(0.0f, 3.0f, 0.0f);
    return enemy;
}//end makeEnemy

字符类如下:

public class Character {

    private String modelLocation; //the location of the model
    private int hitPoints;
    private int atk;
    private int score;

    Character() {
        modelLocation = "Models/Ninja/Ninja.mesh.xml";//makes the ninja the default character
        hitPoints = 10;
        atk = 1;
        score = 0;
    }//end no argument constructor

    /*
    This will be the constructor used primarily for 
    creating enemy characters.
    */
    Character(String s){
        if(s=="ogre"){
            modelLocation = "Models/Sinbad.j3o";
            hitPoints = 5;
            atk = 1;
            score= 0;
        } else {
            modelLocation = "Models/Oto/Oto.mesh.xml";
            hitPoints = 10;
            atk = 1;
            score = 0;
        }
    }//end constructor

    /*
    This constructor will be used for 
    creating the player character.
    */
    Character(String s, int h, int a){
        modelLocation = s;
        hitPoints = h;
        atk = a;
        score= 0;//score always starts at zero
    }//end constructor

    /*
    Getter Methods
    */
    public String getLocation() {
        return modelLocation;
    }//end getLocation
    public int getHitPoints() {
        return hitPoints;
    }//end getHitPoints
    public int getAtk() {
        return atk;
    }//end getAtk
    public int getScore() {
        return score;
    }//end getScore

    /*
    Setter methods
    */
    public void setHitPoints(int n) {
        hitPoints = n;
    }//end setHitPoints
    public void setAtk(int n) {
        atk = n;
    }//end setAtk
    public void setScore(int n) {
        score = n;
    }//end setScore

    //method to deal damage to character
    public void takeDamage(int a) {
        hitPoints = hitPoints - a;
    }//end takeDamage

    //mehtod to add to character score
    public void addScore() {
        if(modelLocation == "Models/Sinbad.j3o") {
            score = score + 1; // 1 point for a ogre
        } else {
            score = score + 2; //2 points for golems
        }//end if else
    }//end addScore
}//end character

在另一种方法中，我可以访问在此方法中创建的空间并对其进行更改，但不能访问创建的 emy 角色对象。我只需要知道如何从方法外部访问其 hitPoints 变量等。

Answer 1

局部变量只能“本地”访问，这意味着只能在其创建的范围内(通常由大括号({})定义)(只有方法知道它们在哪里)。

要解决上述问题并使具有字符的变量在方法外部可用，您有几个选择:

• 将Character变量实现为实例(甚至可能是类变量)并在方法内对其进行初始化。
• 更好的方法是通过您的方法返回 Character 变量。

假设 Spatial 对象描述了角色的位置，您可以将角色和空间作为键值对返回。在这种情况下，我会采用另一种方法，并在角色对象本身内为每个角色定义空间(我不知道您的体系结构是否允许这样做)。