Java GUI没有显示

import java.util.Scanner; 

import javax.swing.*; 
@SuppressWarnings("serial") 
public class Synthetic_Division extends JFrame{ 
public void init(){ 
    JTextField JTF = new JTextField(); 
    JLabel label = new JLabel(); 
    JPanel panel = new JPanel(); 
    panel.add(label); 
    panel.add(JTF); 
    this.add(panel); 
} 
public Synthetic_Division(){ 
    super("Synthetic Division"); 
    this.init(); 
    this.setSize(600, 400); 
    this.setVisible(true); 

} 
public static void main(String[] args) { 
    int sol01 = 0, sol12 = 0, sol23 = 0, sol34 = 0, sol45 = 0, cross12 = 0, cross23 = 0, cross34 = 0, cross45 = 0, cross56 = 0, Remainder = 0, Divisor = 0, Number1 = 0, Number2 = 0, Number3 = 0, Number4 = 0, Number5 = 0, Number6 = 0, NumberOfNumbers = 0; 
    System.out.println("Please input the following values accordingly."); 
    System.out.println("1. Numbers in equation (: 4-6 :)"); 
    System.out.println("2. Divisor (: After the sign has been flipped :)"); 
    System.out.println("3. First Number"); 
    System.out.println("4. Second Number"); 
    System.out.println("5. Third Number"); 
    System.out.println("6. Fourth Number"); 
    System.out.println("7. Fifth Number (: If Needed :)"); 
    System.out.println("8. Sixth Number (: If Needed :)"); 
    Scanner in = new Scanner(System.in); 
    NumberOfNumbers = in.nextInt(); 
    Divisor = in.nextInt(); 
    Number1 = in.nextInt(); 
    Number2 = in.nextInt(); 
    Number3 = in.nextInt(); 
    Number4 = in.nextInt(); 
    if (NumberOfNumbers == 5 || NumberOfNumbers == 6) { 
     Number5 = in.nextInt(); 
    } 
    if (NumberOfNumbers == 6) { 
     Number6 = in.nextInt(); 
    } 
    if (NumberOfNumbers == 4) { 
     sol01 = Number1; 
     cross12 = sol01 * Divisor; 
     sol12 = Number2 + cross12; 
     cross23 = sol12 * Divisor; 
     sol23 = Number3 + cross23; 
     cross34 = sol23 * Divisor; 
     Remainder = Number4 + cross34; 
     if (Remainder == 0) { 
      System.out.println(sol01 + " + " + sol12 + " + " + sol23 
        + " with no remainder! "); 
     } else { 
      System.out.println(sol01 + " + " + sol12 + " + " + sol23 
        + " with a remainder of: " + Remainder); 
     } 

    } else if (NumberOfNumbers == 5) { 
     sol01 = Number1; 
     cross12 = sol01 * Divisor; 
     sol12 = Number2 + cross12; 
     cross23 = sol12 * Divisor; 
     sol23 = Number3 + cross23; 
     cross34 = sol23 * Divisor; 
     sol34 = Number4 + cross34; 
     cross45 = sol34 * Divisor; 
     Remainder = Number5 + cross45; 
     if (Remainder == 0) { 
      System.out.println(sol01 + " + " + sol12 + " + " + sol23 + " + " 
        + sol34 + " with no remainder! "); 
     } else { 
      System.out.println(sol01 + " + " + sol12 + " + " + sol23 
        + " + " + sol34 + " with a remainder of: " + Remainder); 
     } 
    } else if (NumberOfNumbers == 6) { 
     sol01 = Number1; 
     cross12 = sol01 * Divisor; 
     sol12 = Number2 + cross12; 
     cross23 = sol12 * Divisor; 
     sol23 = Number3 + cross23; 
     cross34 = sol23 * Divisor; 
     sol34 = Number4 + cross34; 
     cross45 = sol34 * Divisor; 
     sol45 = Number5 + cross45; 
     cross56 = sol45 * Divisor; 
     Remainder = Number6 + cross56; 
     if (Remainder == 0) { 
      System.out.println(sol01 + " + " + sol12 + " + " + sol23 + " + " 
        + sol34 + " + " + sol45 + " with no remainder! "); 
     } else { 
      System.out.println(sol01 + " + " + sol12 + " + " + sol23 
        + " + " + sol34 + " + " + sol45 
        + " with a remainder of: " + Remainder); 
     } 
    } else { 
     System.out.println("Please input correct number of numbers"); 
    } 

} 
}

出于某种原因，当我运行此代码时，没有GUI显示，但有一个程序开始运行，我可以随时停止。正如你可能通过代码所说的那样，我对Java来说是个新手。我只是添加了其余的代码，希望对故障排除有所帮助，但我仍然没有将GUI实现到主类中，因为我想查看GUI是否是我想要的第一个。Java GUI没有显示

来源

2014-01-18 YourMomMinecraft

你的main（） – TwilightSun

您错过了您的程序中的“入口”。在java中，这是我添加到您提供的代码中的main()方法。你只需要实际创建你写的类的一个对象。另外，如果您打算进入秋千开发阶段，您可能需要查看Swing的EDT（Event Dispatching Thread）。找到它here。

import javax.swing.*; 

@SuppressWarnings("serial") 
public class Synthetic_Division extends JFrame { 
    void init() { 
     JTextField JTF = new JTextField(); 
     JLabel label = new JLabel(); 
     JPanel panel = new JPanel(); 
     panel.add(label); 
     panel.add(JTF); 
     this.add(panel); 
    } 

    public Synthetic_Division() { 
     super("Synthetic Division"); 
     this.init(); 
     this.setSize(600, 400); 
     this.setVisible(true); 
    } 

    //Here is the part you were missing. Everything else is fine. 
    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable(){ 
      public void run() { 
       new Synthetic_Division(); 
      } 
     }); 
    } 
}

编辑

看到您的编辑后，我能看到的主要问题是，你永远不创建类的实例。你失踪的主要是new Synthetic_Division();。其他一些提示：尽量不要将命令行（System.out.println()）和GUI代码合并到一个程序中。这会让您和用户很快感到困惑。此外，请尝试遵守标准的Java命名约定。类以大写字母开始，每个单词后面也是大写字母SyntheticDivision而变量以小写字母开头，每个单词后面都是大写字母myVariableToWorkWith。

来源

2014-01-18 03:28:43 csmckelvey

哪里是初始线程 – MadProgrammer

我没有在任何地方看到main类，这是Java在启动时所期望的。看看下面的代码块：

import javax.swing.*; 
@SuppressWarnings("serial") 
public class Synthetic_Division extends JFrame 
{ 
    public static void main(String[] args) 
    { 
     JFrame frame = new JFrame(); 
     JTextField JTF = new JTextField(); 
     JLabel label = new JLabel(); 
     JPanel panel = new JPanel(); 
     panel.add(label); 
     panel.add(JTF); 
     frame.add(panel); 
     frame.setTitle("Synthetic Division"); 
     frame.setSize(600, 400); 
     frame.setVisible(true); 
    } 
}

来源

2014-01-18 03:29:24

你从来没有在main实例Synthetic_Division。
```
new Synthetic_Division(); 
```
设计很差试图用GUI
混合控制台，您需要指定一个大小为您的文本字段，这样
```
new JTextField(20); 
```

从EDT像这样运行程序

public static void main(String[] args) { 
    SwingUtilities.invokeLater(new Runnable(){ 
     public void run() { 
      new Synthetic_Division(); 
      // everything else here 
     } 
    }); 
}

来源

2014-01-18 03:37:28

-1

// you need to make an object of Synthetic_Division. 
Synthetic_Division SD = new Synthetic_Division();

我希望它能正常工作。

来源

2014-07-21 22:25:21

Java GUI没有显示

回答

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