我有两个扩展JComponent的对象,这两个对象都覆盖paintComponent()。当仅将一个添加到Jpanel时,它就可以正确绘制,但是如果我添加两者,则仅显示一个。

我的初始化方法将两者都添加如下:

public class Applet extends JApplet {

long time_interval = 200; // length of time between moves in ms
int w = 75;
int h = 75;
int[][] a = new int[w][h]; // creates a 2D array to use as background
Creature test;

public void init() {
    System.out.println("Zachary Powell 1104583");
    resize(750, 850);

    WorldView tv = new WorldView(a);
    // add(applet, BorderLayout.CENTER);

    test = new Creature(100, 30, 1);
    add(tv);
    add(test);

    startTimer();
}
...


但是电视没画

我的生物课:

public class Creature extends JComponent{
    int health;
    boolean dead;
    int xpos, ypos;
    static int size = 10;

    Creature(int h, int y, int x) {
        dead = false;
        health = h;
        ypos = y;
        xpos = x;
    }

    void Update() {
        checkHealth();
    }

    private void checkHealth() {
        if (health <= 0)
            dead = true;
    }

    public void reduceHealth(int amount) {
        health -= amount;
    }

    public void move() {
        if (xpos < 75) {
            xpos++;
        } else {
            xpos = 1;
        }
        reduceHealth(1);
    }

    public void paintComponent(Graphics g) {
        g.setColor(Color.BLUE);
        g.fill3DRect(xpos * size, ypos * size, size, size, true);
    }
}


还有我的WorldView课

public class WorldView extends JComponent {
    static Color[] colors =
            {black, green, blue, red,
                    yellow, magenta, pink, cyan};
    int[][] a;
    int w, h;
    static int size = 10;
    //Create the object with the array give
    public WorldView(int[][] a) {
        this.a = a;
        w = a.length;
        h = a[0].length;
    }

    public void paintComponent(Graphics g) {
        for (int i = 0; i < w; i++) {
            for (int j = 0; j < h; j++) {
                    g.fill3DRect(i * size, j * size,
                            size, size, true);
            }
        }
    }

    public Dimension getPreferredSize() {
        return new Dimension(w * size, h * size);
    }
}

最佳答案

顶级容器的默认布局是BorderLayout。默认情况下,如果不指定约束,则将组件添加到CENTER。但是,只能将一个组件添加到CENTER,因此仅显示最后一个添加的组件。


WorldView应该位于背景中,以Creature为中心


然后将WorldView添加到小程序,并将Creature添加到WorldView。

您将需要在WorldView上使用适当的布局管理器来获取所需的布局。

关于java - 并非所有的JComponent都被绘制,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/22867454/

10-10 12:48