JOptionPane取消按钮

Question

int n = 0, k = 0;

Students stu = new Students();      

while (n <= 0) { 

     try { 
       n = Integer.parseInt(JOptionPane.showInputDialog(stu, "Enter the number of people","Input", JOptionPane.INFORMATION_MESSAGE));

       if (n <= 0) {
        OptionPane.showMessageDialog(stu, "You have given a wrong input!", 
             "Warning", JOptionPane.WARNING_MESSAGE);
       }    
    }

    catch (Exception e) { 
          JOptionPane.showMessageDialog(stu, "You have given a wrong input!",
               "Warning",  JOptionPane.WARNING_MESSAGE);
          n = 0; 
    }
}

Answer 1

在显示OptionDialog之后，必须使用break语句来中断循环。JOptionPane不知道您的循环。

或使用

System.exit(ErrorCode);

而不是中断；

String input = JOptionPane.showInputDialog(null, "Enter name :  ", "New Record!", 

while (n <= 0) { 
 try {
   String input = JOptionPane.showInputDialog(stu, "Enter the number of people","Input", JOptionPane.INFORMATION_MESSAGE);
   if(input == null || input.length() == 0)
   {
    OptionPane.showMessageDialog(stu, "You have given a wrong input!", 
         "Warning", JOptionPane.WARNING_MESSAGE);
      System.exit(0);
   }

   n = Integer.parseInt(input);

   if (n <= 0) {
    OptionPane.showMessageDialog(stu, "You have given a wrong input!", 
         "Warning", JOptionPane.WARNING_MESSAGE);
   }    
}

catch (Exception e) { 
      JOptionPane.showMessageDialog(stu, "You have given a wrong input!",
           "Warning",  JOptionPane.WARNING_MESSAGE);
      n = 0; 
}