对 Java gridbaglayout 的帮助？

Question

好吧，我正在尝试将其设置为“输入您的姓名”JLabel 显示在 JTextField 左侧旁边的位置，遗憾的是它显示在中心。我说的是第一个JLabel和第一个JTextArea，其余代码请忽略。

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

public class practice extends JFrame  {

    public static void main(String[] args){
        new practice();
    }

    public practice(){
        JPanel jp = new JPanel();

        jp.setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();

        jp.add(new JLabel(""),gbc);

        gbc.gridx=0;
        gbc.gridy=1;
        jp.add(new JLabel("Enter your name\n"),gbc);

        gbc.gridx=0;
        gbc.gridy=0;
        jp.add(new JLabel(" "),gbc);

        gbc.gridx=0;
        gbc.gridy=0;
        jp.add(new JLabel(" "),gbc);

        gbc.insets = new Insets(30,0,0,0);
        gbc.gridx=0;
        gbc.gridy=1;
        jp.add(new JTextArea(3,30),gbc);

        gbc.insets = new Insets(10,0,0,0);
        gbc.gridx=0;
        gbc.gridy=2;
        jp.add(new JTextArea(3,10),gbc);

        gbc.insets = new Insets(10,0,0,0);
        gbc.gridx=0;
        gbc.gridy=3;
        jp.add(new JTextArea(3,10),gbc);

        gbc.gridx=0;
        gbc.gridy=0;
        jp.add(new JRadioButton(""),gbc);

        gbc.gridx=0;
        gbc.gridy=0;
        jp.add(new JRadioButton (""),gbc);

        gbc.gridx=0;
        gbc.gridy=0;
        jp.add(new JRadioButton(""),gbc);

        this.add(jp);
        setTitle("Card");
        setSize(700,500);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }
}

Answer 1

我建议为您想要放入 GUI 的每个 Swing 组件创建一个 GridBagConstraints。这样，您就不必记住任何默认值，而是为每个组件指定每个参数。

这是我使用 GridBagLayout 的 JDialog。

这是 JDialog 的代码。

package com.ggl.sudoku.solver.view;

import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class SolutionDialog {

    protected static final Insets   buttonInsets    = new Insets(10, 10, 0, 10);

    private int                     singleCount;
    private int                     guessCount;

    private long                    elapsedTime;

    private JDialog                 dialog;

    private SudokuFrame             frame;

    public SolutionDialog(SudokuFrame frame, int singleCount, int guessCount,
            long elapsedTime) {
        this.frame = frame;
        this.singleCount = singleCount;
        this.guessCount = guessCount;
        this.elapsedTime = elapsedTime;
        createPartControl();
    }

    private void createPartControl() {
        dialog = new JDialog(frame.getFrame(), "Statistics");
        dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);

        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));

        JPanel resultsPanel = new JPanel();
        resultsPanel.setLayout(new GridBagLayout());

        int gridy = 0;

        JLabel singleCountLabel = new JLabel("Cells with one possible number:");
        addComponent(resultsPanel, singleCountLabel, 0, gridy, 1, 1,
                buttonInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        String s = singleCount + " cells";
        JLabel singleCountString = new JLabel(s);
        addComponent(resultsPanel, singleCountString, 1, gridy++, 1, 1,
                buttonInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        JLabel guessCountLabel = new JLabel("Cells where the solver guessed:");
        addComponent(resultsPanel, guessCountLabel, 0, gridy, 1, 1,
                buttonInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        s = guessCount + " cells";
        JLabel guessCountString = new JLabel(s);
        addComponent(resultsPanel, guessCountString, 1, gridy++, 1, 1,
                buttonInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        JLabel elapsedTimeLabel = new JLabel("Elapsed Time:");
        addComponent(resultsPanel, elapsedTimeLabel, 0, gridy, 1, 1,
                buttonInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        s = elapsedTime + " milliseconds";
        JLabel elapsedTimeString = new JLabel(s);
        addComponent(resultsPanel, elapsedTimeString, 1, gridy++, 1, 1,
                buttonInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        mainPanel.add(resultsPanel);

        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout());

        JButton okButton = new JButton("OK");
        okButton.setAlignmentX(JButton.RIGHT_ALIGNMENT);
        okButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent event) {
                dialog.setVisible(false);
                dialog.dispose();
            }
        });
        buttonPanel.add(okButton);

        mainPanel.add(buttonPanel);

        dialog.add(mainPanel);
        dialog.pack();
        dialog.setBounds(getBounds());
        dialog.setVisible(true);
    }

    private void addComponent(Container container, Component component,
            int gridx, int gridy, int gridwidth, int gridheight, Insets insets,
            int anchor, int fill) {
        GridBagConstraints gbc = new GridBagConstraints(gridx, gridy,
                gridwidth, gridheight, 1.0D, 1.0D, anchor, fill, insets, 0, 0);
        container.add(component, gbc);
    }

    protected Rectangle getBounds() {
        Rectangle f = frame.getBounds();
        Rectangle d = dialog.getBounds();
        d.x = f.x + (f.width - d.width) / 2;
        d.y = f.y + (f.height - d.height) / 2;
        return d;
    }

}

Answer 2

gridx 和gridy 定义对象将被放置在网格的哪个单元格。它本质上是一个坐标系……就像电子表格一样。

您将许多组件放置在 (0,0) 处，并且在您询问的特定实例中，您同时放置了“输入您的姓名”标签和 JTextArea（与 JTextField 不同）在 (0,1) 处的同一单元格中。因此它们被放置在彼此之上。

Answer 3

如果你想把它放在另一个旁边，你应该尝试这样做：

gbc.gridx = 0;
gbc.gridy = 0; 
Container.add(//Your Label);

gbc.gridx = 1;
gbc.gridy = 0;
Container.add(//Your TextField);

还阅读了关于锚点的信息，因为我没有看到你使用它们，你可以使用：

gbc.anchor = GridBagConstraints.LINE_START;

用于显示自 Line Start 而不是自中心以来的对象。

最后，我建议您创建一种将对象添加到窗口的方法，以避免出现大量代码。 这是我使用的一个非常好的 DEITEL 示例：

import java.awt.


public Yourclass{

JPanel Container;
GridBagLayout yourlayout;
GridBagConstraints gbc;

//Initialize them in the constructor.. Ex: Container = new JPanel();
}


private void addobjects(Component object, int gridx, int gridy, int width, int heigth){

gbc.gridx = gridx;
gbc.gridy = gridy;

gbc.gridwith = width;
gbc.gridheight = height;

yourlayout.setConstraints(object, gbc);
Container.add(object);

}

所以现在你只需要这样做：

addobjects(YourJLabel, 0, 0, 1, 1);
addobjects(YourTextField, 1, 0, 1, 1);

一定要给 widht 和 height 赋值，因为如果没有，构造函数现在不会在哪里添加对象。 并且还要确保在构造函数所在的同一类中声明该方法。

如果我有一些语法错误很抱歉，但我很自豪我的头上有一个 Nopal。贾贾贾。

我希望这个答案可以帮助到你。