java - 当窗口大小改变时扩展框架以填充空间

Question

这是我正在使用的完整相关代码:

    JPanel songDetails = new JPanel(new GridBagLayout() ); 

    GridBagConstraints constraints = new GridBagConstraints();   
        constraints.fill = GridBagConstraints.BOTH; 
        constraints.weightx = 1.0; 
        constraints.gridx = 0; 
        constraints.gridy = 0;  

    for(int i = 0; i < songOptions.length; i++, constraints.gridx++){ 
        songDetails.add(this.buttons[i],constraints);
    }

    constraints.gridy = 1; 

    for(int i = 0; i < songInfo.length; i++, constraints.gridy++){ 

        constraints.gridwidth = 1; 
        constraints.gridx = 0; 
        songDetails.add(this.labels[i],constraints); 

        constraints.gridwidth = GridBagConstraints.REMAINDER; 
        constraints.gridx = 1; 
        songDetails.add(this.fields[i],constraints); 
    }


    JList<Song> list = new JList<Song>(this.lib); //data has type Object[] 
        list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        list.setLayoutOrientation(JList.VERTICAL);
        list.setVisibleRowCount(5);


    JScrollPane listScroller = new JScrollPane();
        listScroller.setViewportView(list);

    constraints.fill = GridBagConstraints.BOTH; 
    constraints.weightx = 1.0; 
    constraints.gridheight = GridBagConstraints.RELATIVE; 
    constraints.gridwidth = GridBagConstraints.REMAINDER; 
    constraints.gridx = 0; 
    constraints.gridy = 0;   
    constraints.anchor = GridBagConstraints.NORTHWEST;
    setLayout(new GridBagLayout());
        add(listScroller,constraints); 
        constraints.gridy++; 
        add(songDetails, constraints); 

在 main 中，我按如下方式初始化框架:

    SongLib myLibrary = new SongLib("Song Library", pathName );
        myLibrary.setVisible(true);
        myLibrary.setSize(300, 250);// Sets the Frame Size
        myLibrary.setMinimumSize(new Dimension(300,250));
        myLibrary.setResizable(true);//Makes the size not fixed
        myLibrary.setLocationRelativeTo(null); // Make the Frame appear centered
        myLibrary.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//Tells program to exit when the 'x'(close) button is pressed

我的问题是，当我扩展框架时，它在水平(宽度)上扩展得很好，但在垂直方向上根本不扩展。我认为更改填充值可以为我做到这一点，但事实并非如此。另外，如果可能的话，在发生此更改时更改字体大小。

如果不是太复杂，我还想让用户能够更改每个框架的相对大小。我认为需要某种 Action 监听器。如果是的话，我会稍后研究，但如果有什么我忽略的事情，我将不胜感激!

Answer 1

代码中的注意事项:

GridBagConstraints constraints = new GridBagConstraints();   
    constraints.fill = GridBagConstraints.BOTH; 
    constraints.weightx = 1.0;   // *********
    constraints.gridx = 0; 
    constraints.gridy = 0;

您没有为 GridBagConstraints 设置权重，只是设置了weightx。设置此项，它将垂直扩展。

例如，

GridBagConstraints constraints = new GridBagConstraints();   
    constraints.fill = GridBagConstraints.BOTH; 
    constraints.weightx = 1.0; 
    constraints.weighty = 1.0;  // ***** added *****
    constraints.gridx = 0; 
    constraints.gridy = 0;