java - 如何使按钮展开Java

Question

我正在尝试创建一个 Java Applet，我在 Java 网站上四处寻找，发现了一个我编辑过的很好的例子。

在这个例子中有 3 个按钮，一个像页眉，一个像页脚和一个像 body 一样的人。我的问题是，中间(正文)按钮不会完全展开。

如果你运行这段代码，你就会明白我的意思。

import java.awt.*;
import javax.swing.JButton;
import javax.swing.JFrame;

public class main {
    final static boolean shouldFill = true;
    final static boolean shouldWeightX = true;
    final static boolean RIGHT_TO_LEFT = false;

    public static void addComponentsToPane(Container pane) {
        if (RIGHT_TO_LEFT) {
            pane.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
        }

        JButton button;
    pane.setLayout(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();
    if (shouldFill) {
    //natural height, maximum width
    c.fill = GridBagConstraints.HORIZONTAL;
    }


    button = new JButton("hi");
    c.fill = GridBagConstraints.HORIZONTAL;
    c.weightx = 0.5;
    c.gridx = 1;
    c.gridy = 0;
    c.ipady = 40;
    pane.add(button, c);

    button = new JButton("Hello, i will not expand");
    c.fill = GridBagConstraints.BOTH;
    c.weighty = 1.0;   //request any extra vertical space
    c.weightx=1.0;
    c.anchor = GridBagConstraints.CENTER; //bottom of space
    c.insets = new Insets(10,0,0,0);  //top padding
    c.gridx = 1;       //aligned with button 2
    c.gridy = 1;       //third row
    pane.add(button, c);


    button = new JButton("fr");
    c.fill = GridBagConstraints.HORIZONTAL;
    c.ipady = 0;       //reset to default
    c.weighty = 1.0;   //request any extra vertical space
    c.anchor = GridBagConstraints.PAGE_END; //bottom of space
    c.insets = new Insets(10,0,0,0);  //top padding
    c.gridx = 1;       //aligned with button 2
    c.gridwidth = 2;   //2 columns wide
    c.gridy = 2;       //third row
    pane.add(button, c);
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("main");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Set up the content pane.
        addComponentsToPane(frame.getContentPane());

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Answer 1

看起来不是中间按钮的错，而是底部按钮没有展开，如果你这样设置底部按钮 c.fill = GridBagConstraints.BOTH; 那么它会占用空的下面的空间。

你想让中间大一点吗？您可能希望将底部按钮的权重更改为 .5c.weighty = .5;//请求任何额外的垂直空间
看看这是否是您要找的东西？

如果你想让中间比顶部和底部大得多，你可能需要制作更多的网格空间，所以不要用 1,1,1，试试 1,3,1 等等