java - Netbean java 图形用户界面

Question

我是 JFrame 新手，并且在 NetBean 中遇到布局问题，如何解决此布局问题？我尝试调整大小，但元素的位置会变得困惑。我试图将每个细节显示到指定的文本区域。我使用了错误的布局还是我的编码有问题？帮助...><

这是我现在的输出

这就是我想要的输出

这些是我的编码:

public class PokemonJournal extends JFrame
    implements ActionListener {

JTextArea FirstName = new JTextArea(1, 10);
JTextArea LastName = new JTextArea(1, 10);
JTextArea Level = new JTextArea(1, 10);
JTextArea Gender = new JTextArea(1, 10);
JButton showPokemon = new JButton("Show");
JButton showRaid = new JButton("Show");
JButton showPokestop = new JButton("Show");
DBHandler db = new DBHandler();
ImageIcon image = new ImageIcon("p1.jpg");
JLabel imageLabel = new JLabel(image);

public static void main(String[] args) {
    PokemonJournal jf = new PokemonJournal();
}

public PokemonJournal() {
    setLayout(new FlowLayout());
    setSize(300, 600);
    setTitle("              Pokemon Journal         ");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    setLocationRelativeTo(null);
    setResizable(false);

    JPanel top = new JPanel();
    add("north", top);
    top.add(new Label("Pokemon Journal"));

    JPanel side = new JPanel();
    add("West", side);
    side.setLayout(new GridLayout());
    side.add(imageLabel);

    JPanel line1 = new JPanel();
    add("center", line1);
    line1.setLayout(new GridLayout());
    line1.add(new Label("First Name :"));
    line1.add(FirstName);

    JPanel line2 = new JPanel();
    add("Center", line2);
    FirstName.setEditable(false);
    line2.setLayout(new GridLayout());
    line2.add(new Label("Last Name   :"));
    line2.add(LastName);
    LastName.setEditable(false);

    JPanel line3 = new JPanel();
    add("Center", line3);
    line3.setLayout(new GridLayout());
    line3.add(new Label("Level      :"));
    line3.add(Level);
    Level.setEditable(false);

    JPanel line4 = new JPanel();
    add("Center", line4);
    line4.setLayout(new GridLayout());
    line4.add(new Label("Gender  : "));
    line4.add(Gender);
    Gender.setEditable(false);

    JPanel line5 = new JPanel();
    add("Center", line5);
    line5.setLayout(new GridLayout());
    line5.add(new Label("Pokemon Caught:"));
    line5.add(showPokemon);

    JPanel line6 = new JPanel();
    add("Center", line6);
    line6.setLayout(new GridLayout());
    line6.add(new Label("Raid Won:"));
    line6.add(showRaid);

    JPanel line7 = new JPanel();
    add("Center", line7);
    line7.setLayout(new GridLayout());
    line7.add(new Label("Pokestop visited:"));
    line7.add(showPokestop);

}

Answer 1

Am i using the wrong layout or my coding are having problems?

嗯，是的，有一点，但这与你的 JFrame 的大小有更多关系。 ，永远不要打电话setSize()请调用 pack() 。但是，如果将其更改为 pack() ， FlowLayout 的默认方向是 FlowLayout.HORIZONTAL因此您的所有组件都将位于彼此的右侧。

然后，您有 2 个选择:

1. 保留JFrame的布局为FlowLayout但做两个JPanel s，一个用于图像，一个用于数据，图像可能具有默认值 FlowLayout也一样，但另一个可能有 GridLayout .

2. 使用GridBagLayout对于所有组件，让图像 JLabel高度为 7 个单元格，所有其他单元格的高度为 1。

对于以下示例，我将使用 GridBagLayout选项，我建议您尝试制作多面板选项(选项 1)。

但是，在开始之前我必须提及代码中的其他问题:

• 您没有遵循Java naming conventions :firstWordLowerCaseVariable , firstWordLowerCaseMethods() , FirstWordUpperCaseClasses , ALL_WORDS_UPPER_CASE_CONSTANTS ，这将使您和我们更容易阅读和理解您的代码。

• 您不会更改 JFrame 的行为因此，无需继承它:请参阅 Extends JFrame vs. creating it inside the program了解更多信息。

• 与上述观点相关，明智的做法是将 GUI 构建为 JPanel s 而不是 JFrame s，请参阅:The Use of Multiple JFrames: Good or Bad Practice?同样，我认为您将来可能会遇到类似的问题。

• 您没有将程序放在 Event Dispatch Thread (EDT) 上，请参阅此 related answer看看如何解决这个问题。

• 您正在调用 setSize(...)方法，正如我之前所说，最好调用 pack()方法，将 GUI 大小的计算留给布局管理器。

• 您正在调用 setVisible在将所有组件添加到 GUI 之前，这可能会导致您出现空白或黑屏，它应该是程序中的最后一行。

• 与上述观点相关，我总是喜欢从内到外开始制作 GUI，并以这种方式添加项目，而不是从外到内。

• 你为什么使用 JTextArea s 而不是 JTextField s 用于用户信息？

现在，使用我给您的第二个选项遵循上述建议的代码是这样的:

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.net.MalformedURLException;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

public class PokemonJournal {
    private JFrame frame;
    private JPanel pane;
    private GridBagConstraints gbc;
    private JLabel imageLabel;
    private JLabel firstName;
    private JLabel lastName;
    private JLabel level;
    private JLabel gender;
    private JLabel pokemonCaught;
    private JLabel raidWon;
    private JLabel pokestopVisited;
    private JTextField nameField;
    private JTextField lastNameField;
    private JTextField levelField;
    private JTextField genderField;
    private JButton pokemonCaughtButton;
    private JButton raidWonButton;
    private JButton pokestopVisitedButton;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new PokemonJournal()::createAndShowGui);
    }

    private void createAndShowGui() {
        frame = new JFrame(getClass().getSimpleName());
        pane = new JPanel();
        pane.setLayout(new GridBagLayout());

        gbc = new GridBagConstraints();

        imageLabel = new JLabel();
        try {
            imageLabel.setIcon(new ImageIcon(
                    new URL("http://pm1.narvii.com/6535/1b362404d09091a335ce53fa68506827418890a3_128.jpg")));
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

        firstName = new JLabel("First Name: ");
        lastName = new JLabel("Last Name: ");
        level = new JLabel("Level: ");
        gender = new JLabel("Gender: ");
        pokemonCaught = new JLabel("Pokemon Caught: ");
        raidWon = new JLabel("Raid Won: ");
        pokestopVisited = new JLabel("Pokestop Visited: ");

        nameField = new JTextField(10);
        lastNameField = new JTextField(10);
        levelField = new JTextField(10);
        genderField = new JTextField(10);

        pokemonCaughtButton = new JButton("Show");
        raidWonButton = new JButton("Show");
        pokestopVisitedButton = new JButton("Show");

        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.gridheight = 7;
        gbc.fill = GridBagConstraints.BOTH;
        gbc.insets = new Insets(5, 5, 5, 5);

        pane.add(imageLabel, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        pane.add(firstName, gbc);

        gbc.gridx = 2;
        pane.add(nameField, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        gbc.gridy++;
        pane.add(lastName, gbc);

        gbc.gridx = 2;
        pane.add(lastNameField, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        gbc.gridy++;
        pane.add(level, gbc);

        gbc.gridx = 2;
        pane.add(levelField, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        gbc.gridy++;
        pane.add(gender, gbc);

        gbc.gridx = 2;
        pane.add(genderField, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        gbc.gridy++;
        pane.add(pokemonCaught, gbc);

        gbc.gridx = 2;
        pane.add(pokemonCaughtButton, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        gbc.gridy++;
        pane.add(raidWon, gbc);

        gbc.gridx = 2;
        pane.add(raidWonButton, gbc);

        gbc.gridx = 1;
        gbc.gridheight = 1;
        gbc.gridy++;
        pane.add(pokestopVisited, gbc);

        gbc.gridx = 2;
        pane.add(pokestopVisitedButton, gbc);

        frame.add(pane);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

它会生成一个与此类似的 GUI: