Java布局定位与NetBeans与Eclipse

Question

我正在尝试创建一个简单的幻灯片程序，如Powerpoint。为了设计它的GUI，我使用Netbeans，然后将GUI代码从Netbeans复制到Eclipse中。

Netbeans生成了以下代码:

    pg = new javax.swing.JPanel();
    jScrollPane1 = new javax.swing.JScrollPane();
    jPanel1 = new javax.swing.JPanel();
    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setBackground(new java.awt.Color(153, 153, 153));
    pg.setBackground(new java.awt.Color(255, 255, 255));
    pg.setForeground(new java.awt.Color(255, 255, 255));
    pg.setPreferredSize(new java.awt.Dimension(255, 234));
    javax.swing.GroupLayout pgLayout = new javax.swing.GroupLayout(pg);
    pg.setLayout(pgLayout);
    pgLayout.setHorizontalGroup(
        pgLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 357, Short.MAX_VALUE)
    );
    pgLayout.setVerticalGroup(
        pgLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 257, Short.MAX_VALUE)
    );
    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 62, Short.MAX_VALUE)
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 279, Short.MAX_VALUE)
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 82, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addComponent(pg, javax.swing.GroupLayout.DEFAULT_SIZE, 357, Short.MAX_VALUE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 279, Short.MAX_VALUE)
        .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(pg, javax.swing.GroupLayout.DEFAULT_SIZE, 257, Short.MAX_VALUE)
            .addContainerGap())
    );
    pack();

我的问题是，我想把右边的jPanel1更改为我自己的类，它扩展了JPanel。为此，我写:

JPanel jPanel1 = new JPanel();  
jPanel1.add(new ToolBoxGUI("ToolBox"));

但是当我运行代码时，右边没有ToolBoxGUI类按钮。我该如何解决这个问题?

Answer 1

jPanel1使用GroupLayout。要使其可见，必须将ToolBoxGUI添加到这个GroupLayout中。如果您想使ToolBoxGUI成为jPanel1的唯一组件，那么删除设置jPanel1布局的代码:

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
    jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
    .addGap(0, 62, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
    jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
    .addGap(0, 279, Short.MAX_VALUE)
);

并替换为

jPanel1.setLayout(new BorderLayout());

或者，如果您想用ToolBoxGUI替换jPanel1，请删除与上面相同的代码，并使用

初始化jPanel1

jPanel1 = new ToolBoxGUI();