java - 在 JOptionOutput 末尾获取 "1"

Question

简单的程序，只需计算圆的周长、直径和面积。每当我运行该程序时，都很好，只是在最后，Area 值后面总是有一个 1 或 -1。例如，当使用半径 10 时，我得到:

Results
The circumference of the circle is: 62.832 Centimeters
The diameter of the circle is: 20.0 Centimeters
The area of the circle is: 314.159 Centimeters1

代码如下:

import javax.swing.JOptionPane;
import java.text.DecimalFormat;

public class Circle {

    public static void main(String[] args)
    {
    //Declarations
    double radius;
    String getRadius;

    //Formatting
    DecimalFormat formatter = new
    DecimalFormat(".000");

    //Calculations
    getRadius = JOptionPane.showInputDialog("Enter Circle Radius In Centimeters:");
    radius = Double.parseDouble(getRadius);

    //Output
    JOptionPane.showMessageDialog(null, "Results" + 
            "\n The circumference of the circle is: " + formatter.format(2*Math.PI*radius) + " Centimeters" +
            "\n The diameter of the circle is: " + 2*radius + " Centimeters" +
            "\n The area of the circle is: " + formatter.format(Math.PI*Math.pow(radius,2)) + " Centimeters" +
            JOptionPane.INFORMATION_MESSAGE);
    }
}

Answer 1

您正在将 JOptionPane.INFORMATION_MESSAGE(恰好等于 1)附加到字符串中。它应该是这样的:

JOptionPane.showMessageDialog(null, 
        "Results" + 
        "\n The circumference of the circle is: " + formatter.format(2*Math.PI*radius) + " Centimeters" +
        "\n The diameter of the circle is: " + 2*radius + " Centimeters" +
        "\n The area of the circle is: " + formatter.format(Math.PI*Math.pow(radius,2)) + " Centimeters", 
        "Results", 
        JOptionPane.INFORMATION_MESSAGE);

四个参数分别是parent、message、title、messageType。之前，您不小心使用了双参数版本(父级、消息)并将 messageType 附加到消息中。