我无法修复的小 GUI 问题。 JTextFields

Question

我做不到的小错误。所以现在我的程序 GUI 看起来像这样：

现在 'Mark' 列下有一个 TextField，用户可以输入他们的数据。如果我想在 'Weight' 列的正下方插入一个 TextField，我也想要重量部分。

然而，当我尝试放入一个 TextField 时，当 window 较小时，两个 Textfields 都会变成这样：

当 window 放大时：

我怎样才能使标记和重量下有一个文本字段？

代码：

public class Gradeanalysis implements ActionListener {

public void actionPerformed (ActionEvent e){
     GridBagConstraints gbc = new GridBagConstraints();

    //Adding the JPanels. Panel for instructions
    JPanel panel = new JPanel();
    panel.setLayout(new GridBagLayout());

    //JLabel for the Instructions.
    JLabel label = new JLabel("<html> Instructions: Type in the grades you’ve received, along with the weights they’ll have in the determination of your overall average. <br> After you press ‘Calculate’, the results will show your average so far. <br> Every grade you enter must be a non-negative number, and every percentage/weight you enter must be a positive number :)</html>");
    gbc.fill = GridBagConstraints.HORIZONTAL;
    gbc.gridwidth = 2;
    gbc.gridy = 0;
    panel.add(label, gbc);


    //JLabel1 for Assingment/Grade/Weight(Percent)
    JLabel label1 = new JLabel("<html><pre>Assingment\t\t\t\t\t  Mark\t\t\t\t\tWeight</pre></html>");
    gbc.fill = GridBagConstraints.HORIZONTAL;
    gbc.gridx = 0;
    gbc.gridy = 1;
    gbc.anchor = GridBagConstraints.NORTH;
    panel.add(label1, gbc);

    //JLabel Numbers for the number list of assingments at the side.
    JLabel numbers = new JLabel("1");
    gbc.gridx = 0;
    gbc.gridy = 2;
    gbc.anchor = GridBagConstraints.NORTH;
    gbc.weighty = 1;
    panel.add(numbers, gbc);        

    //JTextfield for Mark
    JTextField mark = new JTextField(2);
    gbc.fill = GridBagConstraints.NONE;
    gbc.gridy = 2;
    panel.add(mark, gbc);


    //JTextfield for Weight
    JTextField weight = new JTextField(2);
    gbc.gridx = 2;
    panel.add(weight, gbc);


    //New frame set
    JFrame frame = new JFrame("Grade Calculator-- ");
    frame.setVisible(true);
    frame.setSize(750,700);
    frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
    frame.add(panel);




}

}

感谢阅读。

Answer 1

您可以像这样设置每个 JTextField 的最小、预期和最大大小：

JTextField t = new JTextField();
t.setMaximumSize(MAX);
t.setMinimumSize(MIN);
t.setBounds(x, y, width, height);

其中 MIN 和 MAX 是维度对象，设置边界的输入是 int

Answer 2

这是我创建的 GUI。

我不知道您的主要方法在哪里，但是您必须始终通过调用 SwingUtilities invokeLater 方法来启动 Swing 应用程序。 invokeLater 方法将 Swing 组件的创建和执行放在 Event Dispatch thread (EDT).
当我使用 GridBagLayout 时，我使用我创建的 addComponent 方法为每个 Swing 组件创建唯一的 GridBagConstraints。我不喜欢记住默认值。
JFrame 方法的顺序极其重要。记住本例中 JFrame 方法的顺序。
我把说明放在了一个JTextArea中。这样，指令文本将根据 JTextArea 的大小进行拆分。无需使用 HTML.

这是代码。

package com.ggl.testing;

import java.awt.Component;
import java.awt.Container;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

public class GradeAnalysis implements Runnable {

    private static final Insets normalInsets = new Insets(10, 10, 0, 10);
    private static final Insets finalInsets = new Insets(10, 10, 10, 10);

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

    @Override
    public void run() {
        JFrame frame = new JFrame("Grade Calculator");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(createMainPanel());
        frame.pack();
        frame.setVisible(true);
    }

    private JPanel createMainPanel() {
        GridBagConstraints gbc = new GridBagConstraints();

        // Adding the JPanels. Panel for instructions
        JPanel panel = new JPanel();
        panel.setLayout(new GridBagLayout());

        int gridy = 0;

        // JLabel for the Instructions.
        JTextArea instructionTextArea = new JTextArea(5, 30);
        instructionTextArea.setEditable(false);
        instructionTextArea.setLineWrap(true);
        instructionTextArea.setWrapStyleWord(true);
        instructionTextArea.setText(getInstructions());
        JScrollPane instructionScrollPane = new JScrollPane(instructionTextArea);
        addComponent(panel, instructionScrollPane, 0, gridy++, 3, 1,
                finalInsets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);

        // JLabels for Assignment/Grade/Weight(Percent)
        JLabel label1 = new JLabel("Assignment");
        label1.setHorizontalAlignment(JLabel.CENTER);
        addComponent(panel, label1, 0, gridy, 1, 1, finalInsets,
                GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL);

        JLabel label2 = new JLabel("Mark");
        label2.setHorizontalAlignment(JLabel.CENTER);
        addComponent(panel, label2, 1, gridy, 1, 1, finalInsets,
                GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL);

        JLabel label3 = new JLabel("Weight");
        label3.setHorizontalAlignment(JLabel.CENTER);
        addComponent(panel, label3, 2, gridy++, 1, 1, finalInsets,
                GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL);

        // JLabel Numbers for the number list of assignments at the side.
        JLabel number = new JLabel("1");
        number.setHorizontalAlignment(JLabel.CENTER);
        addComponent(panel, number, 0, gridy, 1, 1, normalInsets,
                GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL);

        // JTextfield for Mark
        JTextField mark = new JTextField(20);
        mark.setHorizontalAlignment(JLabel.CENTER);
        addComponent(panel, mark, 1, gridy, 1, 1, normalInsets,
                GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL);

        // JTextfield for Weight
        JTextField weight = new JTextField(20);
        weight.setHorizontalAlignment(JLabel.CENTER);
        addComponent(panel, weight, 2, gridy++, 1, 1, normalInsets,
                GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL);

        return panel;
    }

    private String getInstructions() {
        return "Instructions: Type in the grades you’ve received, along with the weights "
                + "they’ll have in the determination of your overall average. After you "
                + "press ‘Calculate’, the results will show your average so far. Every "
                + "grade you enter must be a non-negative number, and every "
                + "percentage/weight you enter must be a positive number :)";
    }

    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);
    }

}

Answer 3

我建议你

不要在任何组件或 GUI 上使用 setBounds(...)
setSize(...)
而是嵌套 JPanel，每个 JPanel 使用自己的布局来实现令人愉悦且易于管理的布局和 GUI。
考虑将介绍文本放入 JTextArea。如果你想让它看起来像一个JLabel，你可以去掉背景颜色和边框。
最好的方法是在 JTable 中显示表格数据，为此您需要创建自己的 table 模型，该模型基于 AbstractTableModel 并为每个模型使用一个 Assignment 对象行。

一个例子没有 JTable:

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.util.List;

import javax.swing.*;

@SuppressWarnings("serial")
public class GradeAnalysis2 extends JPanel {
   private static final int PREF_H = 400;
   private static final String DISPLAY_TEXT = "Instructions: "
         + "Type in the grades you’ve received, along with the "
         + "weights they’ll have in the determination of your "
         + "overall average.\n"
         + "After you press ‘Calculate’, the results will show "
         + "your average so far.\n"
         + "Every grade you enter must be a non-negative number, "
         + "and every percentage/weight you enter must be a "
         + "positive number :)";
   private JTextArea displayArea = new JTextArea(5, 50);
   private GradeTablePanel gradeTablePanel = new GradeTablePanel();

   public GradeAnalysis2() {
      displayArea.setText(DISPLAY_TEXT);
      displayArea.setWrapStyleWord(true);
      displayArea.setLineWrap(true);
      displayArea.setEditable(false);
      displayArea.setFocusable(false);
      displayArea.setBorder(null);
      displayArea.setBackground(null);

      JPanel centerPanel = new JPanel(new BorderLayout());
      centerPanel.add(gradeTablePanel, BorderLayout.PAGE_START);
      centerPanel.add(Box.createGlue(), BorderLayout.CENTER);
      JScrollPane scrollPane = new JScrollPane(centerPanel);

      JPanel btnPanel = new JPanel();
      btnPanel.add(new JButton(new AddAssignmentAction("Add")));

      setLayout(new BorderLayout());
      add(displayArea, BorderLayout.PAGE_START);
      add(scrollPane, BorderLayout.CENTER);
      add(btnPanel, BorderLayout.PAGE_END);
   }

   @Override
   public Dimension getPreferredSize() {
      Dimension sz = super.getPreferredSize();
      if (isPreferredSizeSet()) {
         return sz;
      }
      int height = Math.max(sz.height, PREF_H);
      return new Dimension(sz.width, height);
   }

   private class AddAssignmentAction extends AbstractAction {
      public AddAssignmentAction(String name) {
         super(name);
         int mnenomic = (int) name.charAt(0);
         putValue(MNEMONIC_KEY, mnenomic);
      }

      public void actionPerformed(ActionEvent e) {
         gradeTablePanel.addAssignment();
         gradeTablePanel.revalidate();
         gradeTablePanel.repaint();
      };
   }

   private class GradeTablePanel extends JPanel {
      private int count = 0;

      // parallel collections -- a bad kludge. 
      // a table model would make this much cleaner
      private List<JTextField> marks;
      private List<JTextField> weights;

      public GradeTablePanel() {
         setLayout(new GridBagLayout());
         JLabel assgmntLbl = new JLabel(Assignment.ASSIGNMENT, SwingConstants.CENTER);
         assgmntLbl.setFont(assgmntLbl.getFont().deriveFont(Font.BOLD));
         JLabel markLbl = new JLabel(Assignment.MARK, SwingConstants.CENTER);
         markLbl.setFont(markLbl.getFont().deriveFont(Font.BOLD));
         JLabel weightLbl = new JLabel(Assignment.WEIGHT, SwingConstants.CENTER);
         weightLbl.setFont(weightLbl.getFont().deriveFont(Font.BOLD));

         add(assgmntLbl, createGbc(0, 0));
         add(markLbl, createGbc(1, 0));
         add(weightLbl, createGbc(2, 0));
      }

      private GridBagConstraints createGbc(int x, int y) {
         GridBagConstraints gbc = new GridBagConstraints();
         gbc.gridx = x;
         gbc.gridy = y;
         gbc.gridwidth = 1;
         gbc.gridheight = 1;
         gbc.fill = GridBagConstraints.VERTICAL;
         gbc.weightx = 1.0;
         gbc.weighty = 1.0;
         gbc.anchor = GridBagConstraints.CENTER;
         return gbc;
      }

      public void addAssignment() {
         count++;
         JLabel countLabel = new JLabel(String.valueOf(count));
         JTextField markField = new JTextField(2);
         JTextField weightField = new JTextField(2);

         add(countLabel, createGbc(0, count));
         add(markField, createGbc(1, count));
         add(weightField, createGbc(2, count));
      }

   }

   private static void createAndShowGui() {
      JFrame frame = new JFrame("GradeAnalysis2");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(new GradeAnalysis2());
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

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


class Assignment {
   public static final String ASSIGNMENT = "Assignment";
   public static final String MARK = "Mark";
   public static final String WEIGHT = "Weight";
   private String assignment;
   private int mark;
   private double weight;
   public Assignment(String assignment, int mark, double weight) {
      this.assignment = assignment;
      this.mark = mark;
      this.weight = weight;
   }
   public String getAssignment() {
      return assignment;
   }
   public void setAssignment(String assignment) {
      this.assignment = assignment;
   }
   public int getMark() {
      return mark;
   }
   public void setMark(int mark) {
      this.mark = mark;
   }
   public double getWeight() {
      return weight;
   }
   public void setWeight(double weight) {
      this.weight = weight;
   }


}

我无法修复的小 GUI 问题。 JTextFields

Small GUI issue I cannot fix. JTextFields

java

user-interface

jlabel

jtextfield

gridbaglayout