Question

如果用户在输入输入后单击否，我会尝试使代码循环。

import java.awt.event.WindowAdapter;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

    public class Sizer extends WindowAdapter 
    {
            public static void main (String[]args){


            JFrame m = new JFrame();
            JOptionPane.showMessageDialog(m,"Ok To set the window size you are going to type in the number for each value REMEMBER THE SIZE IS IN PIXELS");


            String input1= JOptionPane.showInputDialog("Height (suggested under 1080 and above 300)");
            int Height= Integer.parseInt( input1);

在输入之后，我必须确认如果用户单击“是”，则该用户是否正确输入了该信息；如果单击“否”，它将继续进行该操作，我希望它再次让用户键入它吗？

        int a1 = JOptionPane.showConfirmDialog(m,"Are you sure that this is the correct Height"+ Height);
        if (a1==JOptionPane.YES_OPTION){
        if (a1==JOptionPane.NO_OPTION){

        }

        String input2= JOptionPane.showInputDialog("Width (suggested under 1920 and above 300)");
        int Width = Integer.parseInt( input2);




        JFrame frame = new JFrame();                    
        Slop comp = new Slop();
        frame.add(comp);
        frame.setSize(Height,Width);
        frame.setTitle("Slop of a Line");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
                }   
        }
}

`

Answer 1

使用do ... while循环，如果用户单击“否”，则清除高度

public class Sizer extends WindowAdapter 
{
    public static void main (String[]args){

        JFrame m = new JFrame();
        int height = 0;

        JOptionPane.showMessageDialog(m,"Ok To set the window size you are going to type in the number for each value REMEMBER THE SIZE IS IN PIXELS");

        do {
            String input1= JOptionPane.showInputDialog("Height (suggested under 1080 and above 300)");
            height= Integer.parseInt(input1);
            int a1 = JOptionPane.showConfirmDialog(m,"Are you sure that this is the correct Height "+ height);

             if (a1==JOptionPane.NO_OPTION){
                height = 0;
            }

        } while (height==0)
    }

}

这假设高度必须大于0。如果height可以为0，则将-1用作初始值和重置值。

编辑：

@Nicholas K的答案表明您实际上并不需要if语句，而是只需像这样完成while循环：

            a1 = JOptionPane.showConfirmDialog(m,"Are you sure that this is the correct Height "+ height);

        } while (a1==JOptionPane.NO_OPTION)

但是，您需要在方法开始时初始化a1。

Answer 2

您可以使用

    int a1 = 0;
    do { 
      // Read input till user says 'yes
      a1 = JOptionPane.showConfirmDialog(m, "Are you sure that this is the correct Height "+ Height);
    } while (a1 == JOptionPane.NO_OPTION);

因此循环继续运行，直到用户输入值JOptionPane.NO_OPTION

是否可以基于if语句执行循环？

2 个答案: