JComboBox返回索引值

Question

我一直在試圖寫一個遊戲最近，我一直在編寫GUI。由於我是一名新程序員，並且希望保持簡單，所以我只想使用分辨率選擇器（全屏或稍後）。我有CB，我有一個動作監聽器來返回值，還有一個按鈕來替代新的分辨率測量值。但是，每次運行代碼時，我都會嘗試更改分辨率並且什麼都不會發生。

任何人有任何想法？

此外，我想知道如何使它在首次運行時有一個股票決議，但它然後保存您選擇的決議。

謝謝！

傑克

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
import java.util.Random; 
import java.util.Scanner; 


public class GUI_Test{ 

    private JPanel window; 
    private JPanel settings; 
    private JFrame main; 
    private JFrame optionsScreen; 
    private JLabel headerLabel; 
    private JLabel optionsLabel; 
    private JLabel resolution; 
    private JComboBox resolutonOption; 
    String[] resolutionOptions = new String[] { 
      "640x480", "1024x768", "1366x768", "1600x900", "1920x1080" 
    }; 
    int tempResX, tempResY, res; 
    GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice(); 
    int resX = gd.getDisplayMode().getWidth(); 
    int resY = gd.getDisplayMode().getHeight(); 

    public GUI_Test(){ 
     prepareGUI(); 
    } 
    public static void main(String[] args) { 
     GUI_Test GUI = new GUI_Test(); 
     GUI.showGUIDemo(); 
    } 
    private void showGUIDemo() { 
     JButton exit = new JButton("EXIT"); 
     JButton options = new JButton("OPTIONS"); 
     JButton back = new JButton("BACK"); 
     JButton apply = new JButton("APPLY"); 
     JComboBox <String> resolutionOption = new JComboBox<>(resolutionOptions); 

     exit.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       System.exit(0); 
      } 
     }); 

     options.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       optionsScreen.setVisible(true); 
       settings.setVisible(true); 
       window.setVisible(false); 
       main.setVisible(false); 
      } 
     }); 

     back.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       optionsScreen.setVisible(false); 
       settings.setVisible(false); 
       window.setVisible(true); 
       main.setVisible(true); 
      } 
     }); 

     resolutionOption.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       res = resolutionOption.getSelectedIndex(); 

       switch (res) { 
       case 0: 
        tempResX = 640; 
        tempResY = 480; 
        break; 
       case 1: 
        tempResX = 1024; 
        tempResY = 768; 
        break; 
       case 2: 
        tempResX = 1366; 
        tempResY = 768; 
        break; 
       case 3: 
        tempResX = 1600; 
        tempResY = 900; 
        break; 
       case 4: 
        tempResX = 1920; 
        tempResY = 1080; 
        break; 
       } 
      } 
     }); 

     apply.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       resX = tempResX; 
       resY = tempResY; 
      } 
     }); 

     window.add(exit); 
     window.add(options); 
     settings.add(back); 
     settings.add(resolutionOption); 
     settings.add(apply); 

     main.setVisible(true); 
    } 
    private void prepareGUI() { 
     main = new JFrame("Basic GUI"); 
     main.setSize(resX, resY); 
     main.setLayout(new GridLayout(3,1)); 
     main.addWindowListener(new WindowAdapter(){ 
      public void windowClosing(WindowEvent windowEvent) { 
       System.exit(0); 
      } 
     }); 

     optionsScreen = new JFrame("Options"); 
     optionsScreen.setSize(resX, resY); 
     optionsScreen.setLayout(new GridLayout(4,1)); 
     optionsScreen.addWindowListener(new WindowAdapter(){ 
      public void windowClosing(WindowEvent windowEvent) { 
       System.exit(0); 
      } 
     }); 

     headerLabel = new JLabel("AGame", JLabel.CENTER); 
     headerLabel.setSize(100, 50); 

     optionsLabel = new JLabel("Settings", JLabel.CENTER); 
     optionsLabel.setSize(100, 50); 
     resolution = new JLabel("Resolution", JLabel.CENTER); 

     window = new JPanel(); 
     window.setLayout(new FlowLayout()); 

     settings = new JPanel(); 
     settings.setLayout(new FlowLayout()); 

     main.add(headerLabel); 
     main.add(window); 
     main.setVisible(true); 

     optionsScreen.add(optionsLabel); 
     optionsScreen.add(settings); 
     optionsScreen.add(resolution); 

     optionsScreen.setVisible(false); 
     settings.setVisible(false); 
    } 

} 

Answer 1

你應該叫setSize()更改分辨率。而隨後致電setVisible(true)主框架後。如果要隱藏選項屏幕窗口請撥setVisible(false)或dispose()方法。

apply.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       resX = tempResX; 
       resY = tempResY; 
       main.setSize(resX, resY);// apply resolution 
       main.setVisible(true); 
       //optionsScreen.setVisible(false); // hide optionscreen frame 

      } 
     });