Bad compile errors for a setup wizard-Cannot find

问题:

I am making a setup wizard for a tax application and I get errors that I don't know how to solve. Please help! My Error is:

Setup.java:16: error: cannot find symbol
                Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};
                ^
  symbol:   variable Colors
  location: class Setup
Setup.java:17: error: cannot find symbol
                final JList colors = new JList(Colors);
                                               ^
  symbol:   variable Colors
  location: class Setup
Setup.java:24: error: cannot find symbol
                        Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};
                        ^
  symbol: variable Colors
Setup.java:25: error: cannot find symbol

If anybody knows the answer, and uses StackOverflow, please ask them to awnser this question! Here is my code:

import java.awt.event.*;
import javax.swing.event.*;
public class Setup {
    @SuppressWarnings("unchecked")
    private static String colorSelected;
    public static void main(String[] args) {
        final JFrame f = new JFrame("Test Setup wizard");
        Container a = f.getContentPane();
        a.setBackground(Color.white);
        a.setLayout(new  FlowLayout());
        JLabel question1 = new JLabel("What would you like the background color to be?");
        JButton Next = new JButton("Next");
        Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};
        final JList colors = new JList(Colors);
        colors.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        colors.setLayoutOrientation(JList.VERTICAL);
        JScrollPane listScroller = new JScrollPane(colors);
        colors.addListSelectionListener(new ListSelectionListener() {
                public void valueChanged(ListSelectionEvent e) {
                    int index = e.getFirstIndex();
                    Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};
                    String colorSelected = Colors[index];
                    }
                });
        f.add(question1);
        f.add(listScroller);
        f.add(Next);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setSize(500,500);
        f.setVisible(true);
        final ImageIcon img = new ImageIcon("HardDisk.jpg");
        f.setIconImage(img.getImage());
        Next.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent Ev) {
                    final Color[] Selected = new Color[1];
                    if (colorSelected .equals("black")) {
                        Selected[0] = new Color(0,0,0);
                    }
                    else if (colorSelected .equals("blue")) {
                        Selected[0] = new Color(0,0,255);
                    }
                    else if (colorSelected .equals("cyan")) {
                        Selected[0] = new Color(0,225,225);
                    }
                    else if (colorSelected .equals("darkGray")) {
                        Selected[0] = new Color(169,169,169);
                    }
                    else if (colorSelected .equals("gray")) {
                        Selected[0] = new Color(128,128,128);
                    }
                    else if (colorSelected .equals("green")) {
                        Selected[0] = new Color(0,255,0);
                    }
                    else if (colorSelected .equals("lightGray")) {
                        Selected[0] = new Color(211,211,211);
                    }
                    else if (colorSelected .equals("magenta")) {
                        Selected[0] = new Color(255,0,255);
                    }
                    else if (colorSelected .equals("orange")) {
                        Selected[0] = new Color(255,165,0);
                    }
                    else if (colorSelected .equals("pink")) {
                        Selected[0] = new Color(255,20,147);
                    }
                    else if (colorSelected .equals("red")) {
                        Selected[0] = new Color(255,0,0);
                    }
                    else if (colorSelected .equals("white")) {
                        Selected[0] = new Color(255,255,255);
                    }
                    else if (colorSelected .equals("yellow")) {
                        Selected[0] = new Color(255,255,0);
                    }
                f.dispose();
                JLabel complete = new JLabel("You are now complete.");
                JFrame f = new JFrame("Complete");
                Container a = f.getContentPane();
                a.setBackground(Selected[0]);
                f.add(complete);
                f.setSize(500,500);
                f.setVisible(true);
                f.setIconImage(img.getImage());
            }
            });
    }
}

Any help is appreciated! P.S: Only solve the first error!!! That fixes the others too!!!

回答1:

try leaving off the size of the array in the declaration and using curly braces instead of square braces. Such as:

Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};

回答2:

This line is incorrect must be wrapped with {} instead of []

new String[12]["black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"];

Should be

new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};

And you have to add the JSrollPane to the frame instead of your JList.

JScrollPane listScroller = new JScrollPane(colors);
f.add(listScroller);

And also you have to add the JLabel to the contentPane of the JFrame

JLabel question1 = new JLabel("What would you like the background color to be?");
f.add(question1);

As @MadProgrammer always suggest i prefer adding to a container as a JPanel instead of JFrame.

回答3:

new String[12]["black", ...]

should be

new String[]{"black", ...}

or even just

{"black", ...}  // no "new String[]"

You don't need to specify the size; it would be redundant as it's simply the number of elements you've declared.

回答4:

new String[12] here is of Array is 12 but there are 13 elements in your array. 

also no need that

 Colors = new String[12]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};

Just use

 Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};

回答5:

Arrays are not initialised using square brackets, they are initialised with curly brackets, so;

Colors = new String[]{"black", "blue", "cyan", "darkGray", "gray", "green", "lightGray", "magenta", "orange", "pink", "red", "white", "yellow"};

回答6:

Array initializers use {} instead of [] (for the literal part), and you don't declare the size of the array, as:

Colors = new String[] {"black", "blue", "cyan", "darkGray", 
                         "gray",  "green", "lightGray", "magenta", 
                         "orange", "pink", "red", "white", "yellow"};