我创建了一个简单的 Swing 应用程序,它目前由一个 JToolBar、一个 JTree 和一个RSyntaxTextArea 组成,所有这些都在一个 GridBagLayout 内。
JTree 目前只有一个顶部节点,并且只有一个子节点。 带有 JToolBar、JTree 和 RSyntaxTextArea 的完整 UI
当扩展 JTree 的顶部节点时,整个 GridBagLayout 类型“最小化”:
我用谷歌搜索了这个现象,但由于控制台中没有错误消息或其他内容,我现在有点无助。
我正在使用以下代码来创建 UI:
RSyntaxTextArea textArea = new RSyntaxTextArea(50, 150);
textArea.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_JAVA);
textArea.setCodeFoldingEnabled(true);
RTextScrollPane sp = new RTextScrollPane(textArea);
cp.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 0;
c.gridy = 0;
cp.add(createToolbar(), c);
c.gridx = 0;
c.gridy = 1;
c.ipadx = 90;
c.fill = GridBagConstraints.BOTH;
cp.add(createTree(), c);
c.gridx = 1;
c.gridy = 1;
c.fill = GridBagConstraints.HORIZONTAL;
cp.add(sp, c);
...
private JToolBar createToolbar() {
JToolBar tb = new JToolBar("Toolbar", JToolBar.HORIZONTAL);
JButton ob = new JButton(new ImageIcon("..."));
tb.add(ob);
tb.setFloatable(false);
tb.setRollover(true);
return tb;
}
...
private JTree createTree() {
DefaultMutableTreeNode top = new DefaultMutableTreeNode("Projects");
JTree tree = new JTree(top);
DefaultMutableTreeNode test = new DefaultMutableTreeNode("I'm a test!");
top.add(test);
return tree;
}
更新:为了测试目的在您的系统上编译的最小代码示例:
import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
public class Tester extends JFrame {
public Tester () {
initializeComponent();
}
private void initializeComponent() {
JPanel cp = new JPanel(new BorderLayout());
JTextArea textArea = new JTextArea(50, 150);
JScrollPane sp = new JScrollPane(textArea);
cp.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 0;
c.gridy = 0;
cp.add(createToolbar(), c);
c.gridx = 0;
c.gridy = 1;
c.ipadx = 90;
c.fill = GridBagConstraints.BOTH;
cp.add(createTree(), c);
c.gridx = 1;
c.gridy = 1;
c.fill = GridBagConstraints.HORIZONTAL;
cp.add(sp, c);
setContentPane(cp);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setLocationRelativeTo(null);
}
private JTree createTree() {
DefaultMutableTreeNode top = new DefaultMutableTreeNode("Projects");
JTree tree = new JTree(top);
DefaultMutableTreeNode test = new DefaultMutableTreeNode("I'm a test!");
top.add(test);
return tree;
}
private JToolBar createToolbar() {
JToolBar tb = new JToolBar("Toolbar", JToolBar.HORIZONTAL);
JButton ob = new JButton("Button");
tb.add(ob);
tb.setFloatable(false);
tb.setRollover(true);
return tb;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Tester().setVisible(true);
}
});
}
}