如何使用Java Swing制作GUI

Question

所以我最近开始学习面向对象的编程，在Java中做了大部分基本的东西，现在我想从控制台编写改为实际的GUI。

但是我有问题了解它是如何工作的，我在oracle文档中看过所有的东西，但是他们的例子并不那么清晰易懂，也使用了它，但找不到任何好的解释。这是我最后的手段。

这里是我的我的程序GUI应该是什么样子的想法： [这样的] [1]

我不能得出很不错，但所有的复选框应该保持一致！

如果有人能提供给我的代码，将是巨大的，如果不只是一些很好的解释会帮我了很多的解释，我的问题是，当我1米对齐的东西以外得到弄糟。

我当前的代码：

public class Zadatak2 extends JFrame{ 

    /** 
    * @param args the command line arguments 
    */ 
    public static void main(String[] args) { 
     // TODO code application logic here 


     new Zadatak2(); 

    } 


    public Zadatak2(){ 

     JPanel panel1 = new JPanel(); 
     setSize(500, 250); 
     setLocationRelativeTo(null); 
     add(panel1); 
     setDefaultCloseOperation(EXIT_ON_CLOSE); 
     setVisible(true); 




     BorderLayout border1 = new BorderLayout(); 
     panel1.setLayout(border1); 


     JPanel panel2 = new JPanel(); 
     GridLayout grid1 = new GridLayout(3,2); 

     panel2.setLayout(grid1); 
     panel2.add(new JCheckBox("Bold")); 
     panel2.add(new JCheckBox("Italic")); 
     panel2.add(new JCheckBox("Underline")); 


     panel1.add(panel2,BorderLayout.WEST); 



     JPanel panel3 = new JPanel(); 
     GridLayout grid2 = new GridLayout(4,1); 
     panel3.setLayout(grid2); 
     panel3.add(new JCheckBox("Strikerthrough")); 
     panel3.add(new JCheckBox("Teletype")); 
     panel3.add(new JCheckBox("Emphasis")); 
     panel3.add(new JCheckBox("Strong")); 
     panel1.add(panel3,BorderLayout.CENTER); 

     JPanel panel4 = new JPanel(); 
     BorderLayout border2 = new BorderLayout(); 
     panel4.setLayout(border2); 

     panel4.add(new JButton("Apply"), BorderLayout.EAST); 
     panel4.setBorder(BorderFactory.createEmptyBorder(0, 0, 10, 70)); 
     panel1.add(panel4,BorderLayout.SOUTH); 

     JPanel panel5 = new JPanel(); 
     GridLayout grid3 = new GridLayout(2,1); 
     panel5.setLayout(grid3); 
     panel5.add(new JLabel("Sample text")); 
     JTextArea ta = new JTextArea("Sample text"); 
     panel5.setBorder(BorderFactory.createEmptyBorder(5, 0, 10, 30)); 
     ta.setSize(200, 200); 
     panel5.add(ta); 
     panel1.add(panel5,BorderLayout.EAST); 


     setVisible(true); 
    } 

} 

感谢所有人的帮助下，终于做出了正确的图形用户界面，现在我明白变薄好得多。

Answer 1

要将复选框放置在GridLayout中，您不应为每列定义面板。只是定义，把它们像这样：

JPanel panel2 = new JPanel(); 
GridLayout grid1 = new GridLayout(4, 2); 

panel2.setLayout(grid1); 
panel2.add(new JCheckBox("Bold")); 
panel2.add(new JCheckBox("Strikerthrough")); 
panel2.add(new JCheckBox("Italic")); 
panel2.add(new JCheckBox("Teletype")); 
panel2.add(new JCheckBox("Underline")); 
panel2.add(new JCheckBox("Emphasis")); 
panel2.add(new JLabel("")); // fill the empty cell with an empty label 
panel2.add(new JCheckBox("Strong")); 

---

不过，既然你有一个TextArea应该与复选框对齐并跨越几行，我会电子书籍使用GridBagLayout代替。这是更多的代码编写，但比GridLayout更灵活。

一个例子：

public Zadatak2() { 

    JPanel panel1 = new JPanel(); 
    setSize(500, 250); 
    setLocationRelativeTo(null); 
    add(panel1); 
    setDefaultCloseOperation(EXIT_ON_CLOSE); 
    setVisible(true); 

    BorderLayout border1 = new BorderLayout(); 
    panel1.setLayout(border1); 

    JPanel panel2 = new JPanel(); 
    GridBagLayout grid1 = new GridBagLayout(); 

    panel2.setLayout(grid1); 
    panel2.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20)); 

    Insets insets = new Insets(2, 2, 2, 2); 

    GridBagConstraints c = new GridBagConstraints(); 
    c.gridx = 0; 
    c.gridy = 0; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Bold"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 1; 
    c.gridy = 0; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Strikerthrough"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 0; 
    c.gridy = 1; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Italic"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 1; 
    c.gridy = 1; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Teletype"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 0; 
    c.gridy = 2; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Underline"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 1; 
    c.gridy = 2; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Emphasis"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 1; 
    c.gridy = 3; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JCheckBox("Strong"), c); 

    insets = new Insets(2, 40, 2, 2); 
    c = new GridBagConstraints(); 
    c.gridx = 2; 
    c.gridy = 0; 
    c.insets = insets; 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JLabel("Sample text"), c); 

    c = new GridBagConstraints(); 
    c.gridx = 2; 
    c.gridy = 1; 
    c.insets = insets; 
    c.weightx = .5; 
    c.fill = GridBagConstraints.BOTH; 
    c.gridheight = 3; 
    JTextArea ta = new JTextArea("Sample text", 4, 4); 
    JScrollPane sp = new JScrollPane(ta); 
    panel2.add(sp, c); 

    c = new GridBagConstraints(); 
    c.gridx = 2; 
    c.gridy = 5; 
    c.insets = new Insets(40, 40, 2,2); 
    c.anchor = GridBagConstraints.WEST; 
    panel2.add(new JButton("Apply"), c); 


    panel1.add(panel2, BorderLayout.CENTER); 

    pack(); 

    setVisible(true); 
} 

结果：

请参阅GridBagLayoutTutorial和JavaDoc学习此布局的所有选项。

Answer 2

请记住使用其自己的布局嵌套JPanel。例如，您的图像图形用户界面可以成为多种方式之一。整体JPanel可以使用面向线的BoxLayout，左边有一个使用JPanel的GridLayout，使用JPanel的右边的BorderLayout。例如：

其他问题：

• 的JTextArea中应放入一个JScrollPane，然后滚动面板添加到GUI。
• 从不从不设置文本组件的大小或首选大小，尤其是JTextAreas，因为这会阻止它们正常工作，特别是在滚动窗格内时。
• 改为设置JTextArea的列和行属性。
• 避免一般设置尺寸。让GUI组件和布局在添加所有内容并将其设置为可见之前，通过在JFrame上调用pack()来设置它们自己的大小。

例如，只需稍作修改：

import java.awt.BorderLayout; 
import java.awt.Font; 
import java.awt.GridLayout; 

import javax.swing.*; 

@SuppressWarnings("serial") 
public class SimpleGui extends JPanel { 
    private static final String[] CHK_BOX_TEXTS = {"Monday", "Tuesday", "Wednesday", 
      "Thursday", "Friday", "Saturday", "Sunday"}; 
    private String title = "My Title"; 
    private JTextArea textArea = new JTextArea(10, 30); 
    private JButton applyButton = new JButton("Apply"); 

    public SimpleGui() { 
     // gridlayout with 2 columns, variable rows 
     JPanel checkBoxPanel = new JPanel(new GridLayout(0, 2, 4, 4)); 
     for (String chkBoxText : CHK_BOX_TEXTS) { 
      checkBoxPanel.add(new JCheckBox(chkBoxText)); 
     } 
     JPanel leftPanel = new JPanel(); 
     leftPanel.setLayout(new BoxLayout(leftPanel, BoxLayout.PAGE_AXIS)); 
     leftPanel.add(Box.createVerticalStrut(20)); 
     leftPanel.add(checkBoxPanel); 
     leftPanel.add(Box.createGlue());   

     JLabel titleLabel = new JLabel(title, SwingConstants.CENTER); 
     titleLabel.setFont(titleLabel.getFont().deriveFont(Font.BOLD, 20)); 
     JScrollPane scrollPane = new JScrollPane(textArea); 
     JPanel btnPanel = new JPanel(); 
     btnPanel.add(applyButton); 

     JPanel rightPanel = new JPanel(new BorderLayout(5, 5)); 
     rightPanel.add(titleLabel, BorderLayout.PAGE_START); 
     rightPanel.add(scrollPane, BorderLayout.CENTER); 
     rightPanel.add(btnPanel, BorderLayout.PAGE_END);   

     setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5)); 
     setLayout(new BoxLayout(this, BoxLayout.LINE_AXIS)); 
     add(leftPanel); 
     add(rightPanel); 
    } 

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

    public static void main(String[] args) { 
     SwingUtilities.invokeLater(() -> createAndShowGui()); 
    } 
} 

其中为显示：