Question

我有两个jpanel：jpanel1和jpanel2，根据其内容必须具有正确的最小尺寸。 jpanel0是这两个面板的容器，它必须位于框架的左侧。这里是jpanel3，应该占用右侧的剩余可用空间。

如何将jpanel的大小设置为所有可用空间？

我想要的输出：

我目前的输出：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;

import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;

public class Panels {

public static void main(String[] args) {

    JFrame myFrame = new JFrame();
    myFrame.setLayout(new BorderLayout());

    JTabbedPane jtp = new JTabbedPane();

    JPanel jPaneTab1 = new JPanel();
    jPaneTab1.setLayout(new FlowLayout(FlowLayout.LEFT));

    JPanel jpanel0 = new JPanel();
    jpanel0.setLayout(new BoxLayout(jpanel0, BoxLayout.Y_AXIS));
    jpanel0.setBorder(BorderFactory.createTitledBorder("jpanel0"));
    jpanel0.setBackground(Color.RED);


    JPanel jpanel1 = new JPanel();
    jpanel1.setLayout(new GridBagLayout());
    jpanel1.setBorder(BorderFactory.createTitledBorder("jpanel1"));
    GridBagConstraints gc = new GridBagConstraints();
    jpanel1.setBackground(Color.BLUE);

    JLabel jlabel1 = new JLabel("jlabel1");
    gc.gridx = 0;
    gc.gridy = 0;
    gc.anchor = GridBagConstraints.NORTHWEST;
    gc.insets = new Insets(0, 0, 0, 2);
    jpanel1.add(jlabel1, gc);
    JLabel jlabel2 = new JLabel("jlabel2");
    gc.gridx = 0;
    gc.gridy = 1;
    gc.anchor = GridBagConstraints.NORTHWEST;
    gc.insets = new Insets(0, 0, 0, 2);
    jpanel1.add(jlabel2, gc);


    JPanel jpanel2 = new JPanel();
    jpanel2.setLayout(new GridBagLayout());
    jpanel2.setBorder(BorderFactory.createTitledBorder("jpanel2"));
    GridBagConstraints gc2 = new GridBagConstraints();
    jpanel1.setBackground(Color.BLUE);

    JLabel jlabel3 = new JLabel("jlabel3");
    gc2.gridx = 0;
    gc2.gridy = 0;
    gc2.anchor = GridBagConstraints.NORTHWEST;
    gc2.insets = new Insets(0, 0, 0, 2);
    jpanel2.add(jlabel3, gc2);
    JLabel jlabel4 = new JLabel("jlabel4");
    gc2.gridx = 0;
    gc2.gridy = 1;
    gc2.anchor = GridBagConstraints.NORTHWEST;
    gc2.insets = new Insets(0, 0, 0, 2);
    jpanel2.add(jlabel4, gc2);






    JPanel jpanel3 = new JPanel();
    jpanel3.setBackground(Color.YELLOW);
    JLabel jlabel5 = new JLabel("jpanel3");
    jpanel3.add(jlabel5);

    jpanel0.add(jpanel1);
    jpanel0.add(jpanel2);
    jPaneTab1.add(jpanel0, BorderLayout.WEST);
    jPaneTab1.add(jpanel3, BorderLayout.CENTER);        

    JPanel jPaneTab2 = new JPanel();


    jtp.addTab("tab1", jPaneTab1);
    jtp.addTab("tab2", jPaneTab2);

    myFrame.add(jtp);       
    myFrame.setSize(800, 600);
    myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    myFrame.setVisible(true);
}

}

增加：

当我使用BorderLayout作为main（标签面板）时，我遇到了另一个问题：

Answer 1

当您将布局分解为逻辑面板，然后使用不同的布局管理器嵌套面板时，布局会更轻松。

例如，使用带有BorderLayout的面板作为选项卡式窗格的内容。

然后创建一个“骑行侧面板”并将其添加到此面板和“中心面板”

JPanel main = new JPanel( new BorderLayout() );
JPanel rightSide = new JPanel( ... );
JPanel center = new JPanel(...);
main.add(rightSide, BorderLayout.LINE_START);
main.add(center, BorderLayout.CENTER);

然后设置“rightSide”和“center”面板的布局，并为每个面板添加组件。

Answer 2

您不应该使用GridBagLayout，BorderLayout或BoxLayout经理。这些都是90年代过时的经理人。

例如，当你这样做时：

gc.insets = new Insets(0, 0, 0, 2);

你正在硬编码组件之间的像素宽度空间将无法在今天各种各样的屏幕上发挥作用。

Insted，应该选择GroupLayout或MigLayout。

以下是MigLayout经理的工作示例。注意多么容易是使用此管理器创建布局。（四行代码。）另外，我们使用逻辑像素（lp）而不是物理像素。

package com.zetcode;

import java.awt.EventQueue;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import net.miginfocom.swing.MigLayout;

public class PanelsEx extends JFrame {

    public PanelsEx() {

        initUI();
    }

    private void initUI() {

        JTabbedPane tabpane = new JTabbedPane();

        JPanel mainPanel = new JPanel();

        JPanel pnl1 = createPanel("Panel 1");
        JPanel pnl2 = createPanel("Panel 2");
        JPanel pnl3 = createPanel("Panel 3");        

        mainPanel.setLayout(new MigLayout("ins 10lp"));

        mainPanel.add(pnl1, "w 150lp, h 100lp, split 2, flowy, ay top");
        mainPanel.add(pnl2, "w 150lp, h 100lp");
        mainPanel.add(pnl3, "push, grow");

        tabpane.add("First", mainPanel);

        add(tabpane);

        pack();        

        setTitle("Panels");
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

    }

    private JPanel createPanel(String text) {

        JLabel lbl = new JLabel(text);
        JPanel pnl = new JPanel();
        pnl.add(lbl);

        pnl.setBorder(BorderFactory.createEtchedBorder());

        return pnl;
    }

    public static void main(String[] args) {

        EventQueue.invokeLater(() -> {
            PanelsEx ex = new PanelsEx();
            ex.setVisible(true);
        });
    }
}

这是截图：

如何正确设置jpanels的大小？

2 个答案: