JOption从字符串文本调用方法

Question

我不太确定如何问这个问题，但这里是。请查看我的代码(为了方便起见，我简化了代码，不要担心"Sam"是临时的)

public class JeopardyGUI_Main11 extends javax.swing.JFrame {
/**
 * Creates new form JeopardyGUI_Main
 */
public JeopardyGUI_Main11() {
    initComponents();
    setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}
public void info(){
           String[] am = new String[25];
   String[] sp = new String[25];
   String[] mu = new String[25];
   String[] spe = new String[25];
   String[] tv = new String[25];
   String[] mo = new String[25];
   String[] ama = new String[25];
   String[] spa = new String[25];
   String[] mua = new String[25];
   String[] spea = new String[25];
   String[] tva = new String[25];
   String[] moa = new String[25];
   am[0] = "Sam";ama[0] = "Sam";
   am[1] = "Sam";ama[1] = "Sam";
   ...
   am[23] = "Sam";ama[23] = "Sam";
   am[24] = "Sam";ama[24] = "Sam";
   mu[0] = "Sam";mua[0] = "Sam";
   mu[1] = "Sam";mua[1] = "Sam";
   ...
   mu[23] = "Sam";mua[23] = "Sam";
   mu[24] = "Sam";mua[24] = "Sam";

   spe[0] = "Sam";spea[0] = "Sam";
   spe[1] = "Sam";spea[1] = "Sam";
   ...
   spe[23] = "Sam";spea[23] = "Sam";
   spe[24] = "Sam";spea[24] = "Sam";

   tv[0] = "Sam";tva[0] = "Sam";
   tv[1] = "Sam";tva[1] = "Sam";
  ...
   tv[23] = "Sam";tva[23] = "Sam";
   tv[24] = "Sam";tva[24] = "Sam";

   sp[0] = "Sam";spa[0] = "Sam";
   sp[1] = "Sam";spa[1] = "Sam";
  ...
   sp[23] = "Sam";spa[23] = "Sam";
   sp[24] = "Sam";spa[24] = "Sam";

   mo[0] = "Sam";moa[0] = "Sam";
   mo[1] = "Sam";moa[1] = "Sam";
   ...
   mo[23] = "Sam";moa[23] = "Sam";
   mo[24] = "Sam";moa[24] = "Sam";
    int random_int = (int) (Math.random() * ( 0 - 24 ));  
  String am_qu = am[random_int];
  String am_an = ama[random_int];  
  String sp_qu = sp[random_int];
  String sp_an = spa[random_int];
  String mu_qu = mu[random_int];
  String mu_an = mua[random_int];
  String spe_qu = sp[random_int];
  String spe_an = spa[random_int];
  String tv_qu = tv[random_int];
  String tv_an = tva[random_int];
  String mo_qu = mo[random_int];
  String mo_an = moa[random_int];
  }
    pack();
    setLocationRelativeTo(null);
}// </editor-fold>                        
private void sp1ActionPerformed(java.awt.event.ActionEvent evt) {                                    
    // TODO add your handling code here:
}                                                                     

private void sp2ActionPerformed(java.awt.event.ActionEvent evt) {                                    
    // TODO add your handling code here:
}                                   
private void am1ActionPerformed(java.awt.event.ActionEvent evt) {                                    
    // TODO add your handling code here:
    Object[] options = {"Yes, please",
                "No way!"};
int n = JOptionPane.showOptionDialog(null,
""+am_qu,          <-------------------------------------AREA IN QUESTION
"",
JOptionPane.YES_NO_OPTION,
JOptionPane.PLAIN_MESSAGE,
null,     //do not use a custom Icon
options,  //the titles of buttons
options[0]); //default button title

}                                   
private void mo1ActionPerformed(java.awt.event.ActionEvent evt) {                                    
    // TODO add your handling code here:
}                                   
private void am1MouseClicked(java.awt.event.MouseEvent evt) {                                 
    // TODO add your handling code here:
}                                
/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(JeopardyGUI_Main11.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(JeopardyGUI_Main11.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(JeopardyGUI_Main11.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(JeopardyGUI_Main11.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>
    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new JeopardyGUI_Main11().setVisible(true);
        }
    });
}
// Variables declaration - do not modify                     
private javax.swing.JButton am1;
private javax.swing.JButton am2;
private javax.swing.JButton am3;
...
private javax.swing.JButton am4;
private javax.swing.JButton am5;
// End of variables declaration                   

}

在"AREA IN QUESTION"我写的是问题的位置。optionDialog框需要一个字符串的文本，但我想替换它的字符串从"公共void info()"，这将随机化与Math.Random。

因此，如果我要正常运行它，optionDialog应该显示"Sam"(在中间文本区域)。

我很抱歉，如果我没有说清楚这一点，问任何问题，我会等待一个回应，谢谢!

Answer 1

这是一个基本的例子，你可以用不同的方式来构建你的程序，这可能会更有效率:

public class SO {
public static void main(String[] args) throws ClassNotFoundException{
    getinfo();//Set the random question and answer
    Object[] options = {"Yes, please", "No way!"};
    int n = JOptionPane.showOptionDialog(null,
            SO.question,//Reference the question set
            "",
            JOptionPane.YES_NO_OPTION,
            JOptionPane.PLAIN_MESSAGE,
            null,     //do not use a custom Icon
            options,  //the titles of buttons
            options[0]); //default button title
    JOptionPane.showMessageDialog(null, SO.answer);
}
public static void getinfo(){ //Will set question and answer
    int category = new Random().nextInt(2 - 0);//Random number to get a category
    int choice = new Random().nextInt(2 - 0);//Random to get a selection
    SO.question = questions[category][choice];//Get question
    SO.answer = answers[category][choice];//Answer is located in same position in answers array
}
/*Each category is represented by a seperate array within the questions
 * 2 dimensional array.  These are declared as static fields or 'Global fields'
 * This way they are easily accessible and only initialised once
 */
private static String[][] questions = new String[][]{ 
    {"Question 1, category 1", "Question 2 category 1"},//questions[0][*] for one category 
    {"Question 1 category 2", "Question 2 category 2"}//questions[1][*] on another category
};
/*The answers array mirrors the other array so each answer in this 2D array 
 * is in the same position as the relevant question in the questions array
 * 
 */
private static String[][] answers = new String[][]{ 
    {"Answer 1 category 1", "Answer 2 category 1"}, //answers[0][*] for questions [0][*]  
    {"Answer 1 category 2", "Answer 2 category 2"}//answers[1][*] for questions [1][*]
};
//These will each hold a question and an answer
private static String question;
private static String answer;

}

我把它缩小了很多，这样你就可以感受到它是如何工作的。建议您使用的"全局变量"位于底部。这应该有希望让你得到你的问题和答案，你需要的JOPtionPane和防止数组的不断重新初始化。

再一次，如果不确定给我回复，我会看看我能做些什么。好运！

Answer 2

我不确定我理解你的程序，但我假设你试图在info()方法中实例化一些字符串，然后在am1ActionPerformed()方法中使用这些字符串的值。现在，我也不太明白你的问题，但我在你的代码中看到的是一个范围的问题。

你试图在am1ActionPerformed()方法中访问的字符串am_qu不存在，因为它是在info()方法中创建和销毁的。如果您想在其他方法中使用它，请尝试将其改为全局变量。

---

更新

找不到符号的原因是由于作用域的原因它不存在。我不知道你的意思是"我添加了全局而不是void info()"，但你让变量全局的方式是在类中声明它，但在其他所有东西之外;

考虑以下内容:

public class TempClass{
    public String globVar;       //global variable
    public void method1(){
        globVar ="hello";        // Same global variable
    }
    public void method2(){
        globVar ="world!";        // same here too
    }
}

在这里，同一个变量globVar可以被method1()和method2()访问，并且可以被两者修改。在method1之后调用method2()将替换globVar的值现在考虑一个局部变量。

public class TempClass{
    public void method1(){
        String localVar;       //local variable is declared
        localVar = "Hello";    //value assigned to local Variable
    }                          //localVar is destroyed
    public void method2(){
        String localVar;       // different localVar to method1
        localVar = "world";    // value assigned to localVar
    }                          // localVar destroyed
}

这里使用了两个不同的变量，尽管它们被称为相同的。不仅如此，当方法退出时，它们将被销毁，并且不能在其他任何地方使用。最后，考虑到目前为止你在做什么

public class TempClass{
    public void method1(){
        String localVar;           //local variable is declared
        localVar = "Hello World";  //value assigned to local Variable
    }                              //localVar is destroyed
    public void method2(){
        System.out.println(localVar);  // Error. localVar does not exist
    }                                  
}

你可以看到变量在你使用它之前就被销毁了。你需要全局声明它。