GUI Loop問題Java

我是一個嘗試使用基本的GUI函數爲練習中的前56個元素製作簡單問題和回答程序的新手。GUI Loop問題Java

但是，當我運行我的代碼時，我得到隨機代碼運行期間的錯誤。

一個文本框將出現沒有對話只是消息作爲文本框的名稱，並X按鈕退出。有時當我按下X時，它會轉到我代碼中的下一行，其他時候它會退出。因爲它似乎是隨機發生的，所以我很難重現這個錯誤。

我的主要方法是下面貼：

import java.math.*; 
import java.text.DecimalFormat; 
import java.io.*; 
import java.util.*; 
import javax.swing.JOptionPane; 
import java.util.Random; 

//This lab is to study periodc table of elements with simple gui output 
public class practiceFiftyEight 
{ 
public static void main(String[] args) 
{ 

    String input; 

    boolean answer; 

    Random myRan = new Random(); 

    int randInt = 0; 
    //random num from 0 - 56 

    String[] arrayElements = {"Hydrogen","Helium","Lithium","Beryllium","Boron","Carbon","Nitrogen","Oxygen","Fluorine","Neon","Sodium","Mangnesium","Aluminium","Silicon","Phosphorus","Sulfur","Chlorine","Argon","Potassium","Calcium","Scandium","Titanium","Vanadium","Chronium","Manganese","Iron","Cobalt","Nickel","Copper","Zinc", 
    "Gallium","Germanium","Arsenic","Selenium","Bromine","Krypton","Rubidium","Strontium","Yttrium","Zirconium","Niobium","Molybdenum","Technetium","Ruthenium","Rhodium","Palladium","Silver","Cadmium","Indium","Tin","Antimony","Tellurium","Iodine","Xenon","Cesium","Barium"}; 

    String[] arrayEleAbriv = {"H","He","Li","Be","B","C","N","O","F","Ne","Na","Mg","Al","Si","P","S","Cl","Ar","K","Ca","Sc","Ti","V","Cr","Mn","Fe","Co","Ni","Cu","Zn","Ga","Ge","As", 
    "Se","Br","Kr","Rb","Sr","Y","Zr","Nb","Mo","Tc","Ru","Rh","Pd","Ag","Cd","In","Sn","Sb","Te","I","Xe","Cs","Ba"}; 

    int repeat; 

     do 
     { 
     randInt = myRan.nextInt(56); 

     JOptionPane.showMessageDialog(null, " sizes of arrays " + arrayElements.length + " " + arrayEleAbriv.length); 

     JOptionPane.showMessageDialog(null, " What is the symbol of " + arrayElements[randInt]); 

     input = JOptionPane.showInputDialog(null," Enter element symbol (1 - 56) of"); 

     answer = input.equalsIgnoreCase(arrayEleAbriv[randInt]); 

     if(answer) 
     { 
     JOptionPane.showMessageDialog(null, " Correct " + arrayElements[randInt] + " is represented by " + arrayEleAbriv[randInt]); 
     } 
     else 
     { 
      JOptionPane.showMessageDialog(null, " WRONG!!!!! " + arrayElements[randInt] + " is represented by " + arrayEleAbriv[randInt] + " !!!!! "); 
     } 
     repeat = JOptionPane.showConfirmDialog(null, "Press Yes to repeat, No to quit ", "please confirmm", JOptionPane.YES_NO_OPTION); 

     }while(repeat == JOptionPane.YES_OPTION); 
    } 
}

來源

2014-09-10 Ro Siv

鎂被拼寫爲「Mangnesium」。將變量聲明爲更接近它們的用法可能會更好，例如，使用「輸入」和「答案」。我想知道，因爲這個類被命名爲'practiceFiftyEight'，並且每次在循環中打印數組的大小，但是隻有56個元素被支持，如果問題與您的程序的早期版本有關沒有匹配？我試過了，無法重現任何錯誤。 – 2014-09-10 16:57:58

你有什麼記錄嗎？ – m4rtin 2014-09-10 16:59:15

您還有幾個未使用的導入。這將是一個好主意，從文件中讀取元素數據，而不是硬編碼所有內容，但我意識到這僅僅是一個開始。 – 2014-09-10 16:59:18

你應該從EDT調用Swing組件。

如果用戶選擇了取消，那麼也有可能拋出NullPointerException的地方。

以下代碼應該不會凍結。

import java.text.DecimalFormat; 
import javax.swing.SwingUtilities; 
import javax.swing.JOptionPane; 
import java.util.Random; 

//This lab is to study periodc table of elements with simple gui output 
public class PracticeFiftyEight { 
    final static String[] arrayElements = {"Hydrogen","Helium","Lithium","Beryllium","Boron","Carbon","Nitrogen","Oxygen","Fluorine","Neon","Sodium","Magnesium", 
              "Aluminium","Silicon","Phosphorus","Sulfur","Chlorine","Argon","Potassium","Calcium","Scandium","Titanium","Vanadium", 
              "Chromium","Manganese","Iron","Cobalt","Nickel","Copper","Zinc","Gallium","Germanium","Arsenic","Selenium","Bromine", 
              "Krypton","Rubidium","Strontium","Yttrium","Zirconium","Niobium","Molybdenum","Technetium","Ruthenium","Rhodium", 
              "Palladium","Silver","Cadmium","Indium","Tin","Antimony","Tellurium","Iodine","Xenon","Cesium","Barium"}; 

    final static String[] arrayEleAbriv = {"H","He","Li","Be","B","C","N","O","F","Ne","Na","Mg","Al","Si","P","S","Cl","Ar","K","Ca","Sc","Ti","V","Cr","Mn","Fe","Co","Ni","Cu","Zn","Ga","Ge","As", 
       "Se","Br","Kr","Rb","Sr","Y","Zr","Nb","Mo","Tc","Ru","Rh","Pd","Ag","Cd","In","Sn","Sb","Te","I","Xe","Cs","Ba"}; 

    public static void main(String[] args) {    

     SwingUtilities.invokeLater(new Runnable() { 
      public void run() { 

       String input; 

       boolean answer; 

       Random myRan = new Random(); 

       int randInt = 0; 
       //random num from 0 - 56     

       int repeat; 

       do { 
        randInt = myRan.nextInt(56); 

        JOptionPane.showMessageDialog(null, " sizes of arrays " + arrayElements.length + " " + arrayEleAbriv.length); 

        JOptionPane.showMessageDialog(null, " What is the symbol of " + arrayElements[randInt]); 

        input = JOptionPane.showInputDialog(null," Enter element symbol (1 - 56) of"); 

        if(input != null) { // if user press cancel, input is null 
         answer = input.equalsIgnoreCase(arrayEleAbriv[randInt]); 

         if(answer) { 
          JOptionPane.showMessageDialog(null, " Correct " + arrayElements[randInt] + " is represented by " + arrayEleAbriv[randInt]); 
         } else { 
          JOptionPane.showMessageDialog(null, " WRONG!!!!! " + arrayElements[randInt] + " is represented by " + arrayEleAbriv[randInt] + " !!!!! "); 
         } 
        } else { 
         System.out.println("input is null: " + input); 
        } 

        repeat = JOptionPane.showConfirmDialog(null, "Press Yes to repeat, No to quit ", "please confirmm", JOptionPane.YES_NO_OPTION); 

       } while(repeat == JOptionPane.YES_OPTION); 
      } 
     }); 
    } 
}

來源

2014-09-11 16:25:49 MockerTim

GUI Loop問題Java

回答

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