小编Jul*_*ale的帖子

我创建了一个从JPanel扩展的类,其布局属性是GridBagLayout.我基本上需要显示一个JLabel(网格)数组,但是一旦创建了组件我就无法替换它.我试图删除我想要更改的组件,然后放置新组件,但结果很奇怪.例如,我创建了一个10x10 JLabel的数组,并想用这段代码替换position [0] [0]和position [9] [9]:

//At first i have the jpanel layout completely filled

this.remove(0);
this.add((JLabel) start, 0);  //This was created with GridBagLayout.gridx = 0 and GridBagLayout.gridy = 0 and it's fine

this.remove(99);
this.add((JLabel) end, 99); //This was created with GridBagLayout.gridx = 9 and GridBagLayout.gridy = 9 and it's out of grid
this.revalidate();

但只有位置[0] [0]看起来很好.我该怎么做才能更换一个组件？

我正在做一个与编译器设计相关的项目。我需要为基于 Java 的语言生成三个地址代码，这意味着使用对象和范围。我想您是否可以帮助我为以下示例生成 TAC（或向我推荐教程）：

class A {
    int x;
    String y;

    public A(int x, String y) {
       this.x = x;
       this.y = y;
    }
}

import A;

class B {
    int f;
    A foo;

    public B() {
       this.foo = null;
       this.f = -1;
    }

    public boolean createFoo() {
       this.foo = new A(0, "TAC Example");
       return true;
    } 

    public static void main() {
       B bar = new B();
       A baz = new A(666, "TAC generation");
       bar.createFoo();
       bar.foo.y = "Hello World";
       if(bar.foo.x …