如何使用Java佈局管理器以我想要的方式顯示面板？

Question

我目前正在嘗試使用四個面板製作程序。使用GridLayout將三個面板組合在JFrame的左側，最後一個面板佔據屏幕的右側。理想情況下，左側面板佔用JFrame左側的2/3，最後三分之一將被第四個面板佔用。我試圖用很多方式做到這一點，但無法弄清楚。當前顯示將屏幕分成兩半，並顯示黃色，紅色，藍色，但只有540個像素長，而綠色覆蓋左側面板的其餘部分。

這有一個代表最後一個面板的綠色矩形，它與黃色紅色和藍色矩形重疊，其長度應爲720像素。我已經通過重新調整JFrame的大小，直到完成工作，完成了正確顯示我想要的方式。通過重新調整直到矩形排列，我設法使它看起來應該如此。我移動了JFrame的右側，直到兩個相應的面板排成一行，沒有空白或重疊，不幸的是，爲了做到這一點，一邊有大量的空白空間。

這裏是我用來做這個顯示的代碼。我是一個完美的新手，可能完全做錯了。我沒有設置使用GridLayout，我只是想使這個工作正常。

import java.awt.*; 
import javax.swing.*; 
class testJPanel1 extends JPanel  //topLeft 
{ 
    int x,y; 
    //JPanel Tjp1; 
    public testJPanel1() 
    { 
     x=720; 
     y=250; 
     setSize(x,y); 
     setVisible(true); 
    } 
    @Override 
    public void paintComponent(Graphics g) 
    { 
     super.paintComponent(g); 
     //g.fillOval(x,y,50,50); 
     g.setColor(Color.yellow); 
     g.fillRect(0, 0, x, y); 
     g.setColor(Color.black); 
     g.drawString("1",x,y); 
     System.out.println("Hey 1 works"); 
    } 
} 
class testJPanel2 extends JPanel  //mid left 
{ 
    int x,y; 
    public testJPanel2() 
    { 
     x=720; 
     y=260; 
     setVisible(true); 
     setSize(x,y); 
    } 
    @Override 
    public void paintComponent(Graphics g) 
    {super.paintComponent(g); 
     //g.fillOval(x,y,50,50); 
     g.setColor(Color.red); 
     g.fillRect(0, 0, x, y); 
     g.setColor(Color.black); 
     g.drawString("2",x,y); 
     System.out.println("Hey 2 works"); 
    } 
} 
class testJPanel3 extends JPanel  //bot left 
{ 
    int x,y; 
    int boundsx; 
    int boundsy; 
    public testJPanel3() 
    { 
     x=720; 
     y=250; 
     boundsx=200; 
     boundsy=200; 
     setVisible(true); 
     setSize(x,y); 
    } 
    @Override 
    public void paintComponent(Graphics g) 
    { 
     super.paintComponent(g); 
     //g.fillOval(x,y,50,50); 
     g.setColor(Color.blue); 
     g.fillRect(0, 0, x, y); 
     g.setColor(Color.black); 
     g.drawString("3",x,y); 
     System.out.println("Hey 3 works"); 
     // g.drawRect(0,0,boundsx,boundsy); 
    } 
} 
class testJPanel4 extends JPanel  //BIG one on the right 
{ 
    int x,y; 
    int boundsx; 
    int boundsy; 
    public testJPanel4() 
    { 
     x=360; 
     y=760; 
     boundsx=200; 
     boundsy=200; 
     setVisible(true); 
     setSize(x,y); 
    } 
    @Override 
    public void paintComponent(Graphics g) 
    { 
     super.paintComponent(g); 
     g.setColor(Color.green); 
     //g.fillOval(x,y,50,50); 

     g.fillRect(0,0,x,y); 
     g.setColor(Color.black); 
     g.drawString("4",x,y); 
     System.out.println("Hey 4 works"); 
     //g.drawRect(0,0,boundsx,boundsy); 
    } 
} 
class Left_Panel extends JPanel  //Combines 1 and 2 and 3 
{ 
    testJPanel1 tjp1; 
    testJPanel2 tjp2; 
    testJPanel3 tjp3; 
    public Left_Panel() 
    { 
     setLayout(new GridLayout(3,1)); 
     tjp1= new testJPanel1(); 
     tjp2= new testJPanel2(); 
     tjp3= new testJPanel3(); 
     add(tjp1); 
     add(tjp2); 
     add(tjp3); 

    } 
} 

class combo_Panel extends JPanel  //combines left and right panels together 
{ 
    Left_Panel lp; 
    testJPanel4 tjp4; 
    //GOAL IS TO MAKE THIS PANEL lp is 720,760 pixels and tjp4 360,760...still doesnt work 
    public combo_Panel() 
    { 
     setLayout(new GridLayout(1,2));  //HOW TO make this work the way i want it or use something else i want 
     lp= new Left_Panel(); 
     lp.setSize(720,760); 
     tjp4= new testJPanel4(); 
     tjp4.setSize(360,760); 

     add(lp); 
     add(tjp4); 
    } 
} 
class Paint_Window extends JFrame 
{ 
    combo_Panel combo; 
    Paint_Window(String title) 
    { 
     super(title); 
       //setLayout(new BoxLayout(combo,2)); 
       combo = new combo_Panel(); 
     setBounds(new Rectangle(1080,760)); 
     setVisible(true); 
     setDefaultCloseOperation(EXIT_ON_CLOSE); 
       //setLayout(new FlowLayout()); 
       add(combo); 
       //add(tjp5); 
       //tjp1.repaint(); 
    } 
} 
public class testJPanel 
{ 
    public static void main(String args[]) 
    { 
      Paint_Window window = new Paint_Window("Make your choice"); 
    } 

Answer 1

您有幾種選擇，你可以嘗試使用GridLayout在一個容器中奠定了所有三個面板，但可能無法實現，其他的選擇可能是使用GridBagLayout和調整weightx財產以滿足您的要求，例如...

注意紅色的「邊界」，圍繞藍色和綠色的面板，這正顯示出這兩個組件父容器

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.EventQueue; 
import java.awt.GridBagConstraints; 
import java.awt.GridBagLayout; 
import java.awt.GridLayout; 
import java.awt.PopupMenu; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 
import javax.swing.border.EmptyBorder; 

public class TestLayout { 

    public static void main(String[] args) { 
     new TestLayout(); 
    } 

    public TestLayout() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
       } 

       JFrame frame = new JFrame("Testing"); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.setLayout(new BorderLayout()); 
       frame.add(new TestPane()); 
       frame.pack(); 
       frame.setLocationRelativeTo(null); 
       frame.setVisible(true); 
      } 
     }); 
    } 

    public class TestPane extends JPanel { 

     private JPanel leftSide; 
     private JPanel rightSide; 

     public TestPane() { 
      setLayout(new GridBagLayout()); 

      leftSide = new JPanel(new GridLayout(1, 2)); 
      leftSide.setBackground(Color.RED); 
      leftSide.setBorder(new EmptyBorder(1, 1, 1, 1)); 

      leftSide.add(createPanel(Color.BLUE)); 
      leftSide.add(createPanel(Color.GREEN)); 

      GridBagConstraints gbc = new GridBagConstraints(); 
      gbc.gridx = 0; 
      gbc.gridy = 0; 
      gbc.weightx = 0.67; 
      gbc.weighty = 1; 
      gbc.fill = GridBagConstraints.BOTH; 
      add(leftSide, gbc); 

      gbc.gridx = 1; 
      gbc.weightx = 0.33; 
      rightSide = createPanel(Color.MAGENTA); 
      add(rightSide, gbc); 

     } 

     protected JPanel createPanel(Color color) { 
      JPanel panel = new JPanel() { 
       @Override 
       public Dimension getPreferredSize() { 
        return new Dimension(50, 100); 
       } 
      }; 
      panel.setBackground(color); 
      return panel; 
     } 
    } 

}