Small error I can't manage to do. So right now my program GUI looks like this:
现在，“标记”列下有一个文本字段，用户可以在其中输入数据。如果我想在“重量”列下方插入一个文本字段，我也希望重量部分也有相同的效果。
However when I try and put in a TextField, both the the Textfields turn like this when the window is small:
and this when the window is enlarged:
我怎样才能使“标记和重量”下有一个文本字段？
Code:
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);
}
}
谢谢阅读。
这是我创建的 GUI。
我不知道你的主要方法在哪里，但是你必须始终通过调用 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事件调度线程 (EDT) https://docs.oracle.com/javase/tutorial/uiswing/concurrency/dispatch.html.
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 方法的顺序是极其重要。记住本示例中 JFrame 方法的顺序。
我将说明放在 JTextArea 中。这样，指令文本就会根据 JTextArea 的大小进行分割。无需使用 HTML 硬编码换行符。
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);
}
}