Java 作业选项对话框显示在后台
您好,为什么JOption对话框显示在应用程序的后台?我是编程新手,仍然无法解决此错误。尝试以下方法:Java 作业选项对话框显示在后台,java,swing,joptionpane,Java,Swing,Joptionpane,您好,为什么JOption对话框显示在应用程序的后台?我是编程新手,仍然无法解决此错误。尝试以下方法: import java.util.Scanner; import javax.swing.JOptionPane; public class calculator { public static void main(String[] args) { int num1; int num2; String operation; Scanner input =
import java.util.Scanner;
import javax.swing.JOptionPane;
public class calculator {
public static void main(String[] args)
{
int num1;
int num2;
String operation;
Scanner input = new Scanner(System.in);
System.out.println("please enter the first number");
num1 = input.nextInt();
System.out.println("please enter the second number");
num2 = input.nextInt();
System.out.println("Please enter operation");
operation = input.next();
if (operation.equals ("+"))
{
JOptionPane.showMessageDialog(null,"your answer is" + " " + (num1 + num2));
}
if (operation.equals ("-"))
{
JOptionPane.showMessageDialog(null, "your answer is " + " " + (num1 - num2));
}
if (operation.equals ("/"))
{
JOptionPane.showMessageDialog(null,"your answer is" + " " + " " + (num1 / num2));
}
if (operation.equals ("*"))
{
JOptionPane.showMessageDialog(null,"your answer is" + " " + " " + (num1 * num2));
}
}
}
在
null
位置使用此
import java.util.Scanner;
import javax.swing.JOptionPane;
public class calculator {
public static void main(String[] args)
{
int num1;
int num2;
String operation;
Scanner input = new Scanner(System.in);
System.out.println("please enter the first number");
num1 = input.nextInt();
System.out.println("please enter the second number");
num2 = input.nextInt();
System.out.println("Please enter operation");
operation = input.next();
JOptionPane optionPane = new JOptionPane();
if (operation.equals ("+"))
{
JDialog dialog = optionPane.createDialog("your answer is" + " " + (num1 + num2));
dialog.setAlwaysOnTop(alwaysOnTop);
dialog.setVisible(true);
}
if (operation.equals ("-"))
{
JDialog dialog = optionPane.createDialog("your answer is " + " " + (num1 - num2));
dialog.setAlwaysOnTop(alwaysOnTop);
dialog.setVisible(true);
}
if (operation.equals ("/"))
{
JDialog dialog = optionPane.createDialog("your answer is" + " " + " " + (num1 / num2));
dialog.setAlwaysOnTop(alwaysOnTop);
dialog.setVisible(true);
}
if (operation.equals ("*"))
{
JDialog dialog = optionPane.createDialog("your answer is" + " " + " " + (num1 * num2));
dialog.setAlwaysOnTop(alwaysOnTop);
dialog.setVisible(true);
}
}
试试这个
JOptionPane.showMessageDialog(this,"your answer is" + " " + (num1 + num2));
“在后台”是什么意思?在
main(String[])
中不能使用this
!
UIManager UI=new UIManager();
UI.put("OptionPane.background",new ColorUIResource(0,250,0));
// (or)
UI.put("OptionPane.background", Color.green);
UI.put("Panel.background",new ColorUIResource(255,0,0));
// (or)
UI.put("Panel.background", Color.red);
JOptionPane.showMessageDialog(null,"Warning Message for change the color of the ","Forum", JOptionPane.WARNING_MESSAGE);