问题
I am currently creating a Calculator project in java and right now I am only making the design or the GUI for it. This is my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class Calculator extends JFrame {
JButton jcomp1;
JButton jcomp2;
JButton jcomp3;
JTextField jcomp4;
JTextField jcomp5;
JRadioButton rb1;
JRadioButton jcomp7;
JRadioButton jcomp8;
JRadioButton jcomp9;
JRadioButton jcomp10;
JRadioButton jcomp11;
JLabel jcomp12;
JLabel jcomp13;
JButton jcomp14;
JButton jcomp15;
JButton jcomp16;
JButton jcomp17;
JButton jcomp18;
JButton jcomp19;
JButton jcomp20;
JButton jcomp21;
JButton jcomp22;
JButton jcomp23;
JButton jcomp24;
JButton jcomp25;
JButton jcomp26;
JButton jcomp27;
JButton jcomp28;
JButton jcomp29;
JButton jcomp30;
JButton jcomp31;
JButton jcomp32;
JButton jcomp33;
JButton jcomp34;
JButton jcomp35;
public Calculator() {
jcomp1 = new JButton ("A");
jcomp2 = new JButton ("CE");
jcomp3 = new JButton ("C");
jcomp4 = new JTextField (5);
jcomp5 = new JTextField (5);
rb1 = new JRadioButton ("Hex");
jcomp7 = new JRadioButton ("Dec");
jcomp8 = new JRadioButton ("Oct");
jcomp9 = new JRadioButton ("Bin");
jcomp10 = new JRadioButton ("On");
jcomp11 = new JRadioButton ("Off");
jcomp12 = new JLabel ("Palindrome");
jcomp13 = new JLabel ("Test");
jcomp14 = new JButton ("?");
jcomp15 = new JButton ("B");
jcomp16 = new JButton ("C");
jcomp17 = new JButton ("D");
jcomp18 = new JButton ("E");
jcomp19 = new JButton ("F");
jcomp20 = new JButton ("7");
jcomp21 = new JButton ("4");
jcomp22 = new JButton ("1");
jcomp23 = new JButton ("0");
jcomp24 = new JButton ("8");
jcomp25 = new JButton ("5");
jcomp26 = new JButton ("2");
jcomp27 = new JButton (".");
jcomp28 = new JButton ("3");
jcomp29 = new JButton ("6");
jcomp30 = new JButton ("9");
jcomp31 = new JButton ("+");
jcomp32 = new JButton ("-");
jcomp33 = new JButton ("/");
jcomp34 = new JButton ("*");
jcomp35 = new JButton ("=");
setPreferredSize (new Dimension (363, 312));
setLayout (null);
add (jcomp1);
add (jcomp2);
add (jcomp3);
add (jcomp4);
add (jcomp5);
add (rb1);
add (jcomp7);
add (jcomp8);
add (jcomp9);
add (jcomp10);
add (jcomp11);
add (jcomp12);
add (jcomp13);
add (jcomp14);
add (jcomp15);
add (jcomp16);
add (jcomp17);
add (jcomp18);
add (jcomp19);
add (jcomp20);
add (jcomp21);
add (jcomp22);
add (jcomp23);
add (jcomp24);
add (jcomp25);
add (jcomp26);
add (jcomp27);
add (jcomp28);
add (jcomp29);
add (jcomp30);
add (jcomp31);
add (jcomp32);
add (jcomp33);
add (jcomp34);
add (jcomp35);
jcomp1.setBounds (90, 100, 50, 30);
jcomp2.setBounds (145, 100, 50, 30);
jcomp3.setBounds (200, 100, 50, 30);
jcomp4.setBounds (0, 0, 365, 40);
jcomp5.setBounds (0, 45, 365, 40);
rb1.setBounds (0, 100, 50, 25);
jcomp7.setBounds (0, 120, 70, 25);
jcomp8.setBounds (0, 145, 70, 25);
jcomp9.setBounds (0, 170, 60, 25);
jcomp10.setBounds (0, 245, 65, 25);
jcomp11.setBounds (0, 270, 65, 25);
jcomp12.setBounds (5, 205, 75, 25);
jcomp13.setBounds (20, 220, 45, 25);
jcomp14.setBounds (255, 100, 105, 30);
jcomp15.setBounds (90, 135, 50, 30);
jcomp16.setBounds (90, 170, 50, 30);
jcomp17.setBounds (90, 205, 50, 30);
jcomp18.setBounds (90, 240, 50, 30);
jcomp19.setBounds (90, 275, 50, 30);
jcomp20.setBounds (145, 135, 50, 30);
jcomp21.setBounds (145, 170, 50, 30);
jcomp22.setBounds (145, 205, 50, 30);
jcomp23.setBounds (145, 240, 105, 30);
jcomp24.setBounds (200, 135, 50, 30);
jcomp25.setBounds (200, 170, 50, 30);
jcomp26.setBounds (200, 205, 50, 30);
jcomp27.setBounds (255, 240, 50, 30);
jcomp28.setBounds (255, 205, 50, 30);
jcomp29.setBounds (255, 170, 50, 30);
jcomp30.setBounds (255, 135, 50, 30);
jcomp31.setBounds (310, 135, 50, 30);
jcomp32.setBounds (310, 170, 50, 30);
jcomp33.setBounds (310, 205, 50, 30);
jcomp34.setBounds (310, 240, 50, 30);
jcomp35.setBounds (145, 275, 215, 30);
}
public static void main (String[] args) {
Calculator calc = new Calculator();
calc.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
calc.getContentPane().add (new Calculator());
calc.pack();
calc.setVisible (true);
}
}
I am using eclipse to make this layout but I'm afraid I keep getting the error:
Exception in thread "main" java.lang.IllegalArgumentException: adding a window to a container
at java.awt.Container.checkNotAWindow(Container.java:429)
at java.awt.Container.addImpl(Container.java:1037)
at java.awt.Container.add(Container.java:363)
at Calculator.main(Calculator.java:162)
Can you point out what did I do wrong? I tried making a design in GuiGenie but also I still get this error.
回答1:
The problem:
calc.getContentPane().add (new Calculator());
All of your buttons, text fields, etc., should be added to a JPanel, and the JPanel should be added to the content pane of the JFrame.
To do this:
- create a JPanel in the constructor of your Calculator.
- add all your JComponents to the JPanel.
- in the Calculator constructor, add this code:
this.getContentPane().add(jPanel);
回答2:
On this line:
calc.getContentPane().add (new Calculator());
You are attempting to add a calculator to itself. Quite obviously, this is not going to work. You really only need these two lines:
calc.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
calc.setVisible (true);
And they should be in the constructor for Calculator, not in your main method.
来源：https://stackoverflow.com/questions/14804603/java-error-exception-in-thread-main-java-lang-illegalargumentexception-addin