如何在我的GUI上显示我的颜色图标？

Question

I'm trying to create a GUI where I can create custom colors. I have a feature that lets the user preview the color before submitting the color. I can't get the Icon to display at all. The actual problem is in my ColorFrame class. The color Icon(a JLabel, color) is created in the actionperformed() method.

The code that creates the Icon(The ButtonListener class):

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Label;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BoxLayout;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;


public class ColorFrame extends JFrame implements ActionListener {

private JPanel colorPanel;
private JPanel labelPanel;
private JPanel buttonPanel;

private JLabel labelRed;
private JLabel labelGreen;
private JLabel labelBlue;
private JLabel color;

private JTextField redField;
private JTextField greenField;
private JTextField blueField;

private JButton preview;
private JButton submit;


private int redInt;
private int blueInt;
private int greenInt;


private int width = 30;
private int height = 30;

public ColorFrame(int x, int y)
{
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //closes all frames for some reason
    this.pack();
    this.setLocation(x, y);

    buttonPanel = new JPanel();
    this.getContentPane().add(buttonPanel,BorderLayout.SOUTH);
    preview = new JButton("Preview Color");
    preview.addActionListener(new ButtonListener());
    buttonPanel.add(preview);
    createColorPanel();
    createLabelPanel();

    this.setVisible(true);

}

class ButtonListener implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent arg0) {
        //in the gui, there are three jtextfieilds that represent color values. the first is red, the second is green, and the last is blue.
        redInt = Integer.parseInt(redField.getText());
        greenInt = Integer.parseInt(greenField.getText());
        blueInt = Integer.parseInt(blueField.getText());

        color = new JLabel(new ColorIcon(redInt,greenInt,blueInt));
        buttonPanel.add(color,BorderLayout.SOUTH);
        print(redInt,greenInt, blueInt);

    }

}


private void createColorPanel()
{
    colorPanel = new JPanel(new GridBagLayout());

    GridBagConstraints c = new GridBagConstraints();

    //creates the three textfields to input rgb values.
    //the first is r, second, b third g
    redField = new JTextField(2);
    c.fill = GridBagConstraints.VERTICAL;
    c.weightx = 0.5;
    c.gridx = 1;
    c.gridy = 0;
    c.insets = new Insets(10,0,0,10);
    colorPanel.add(redField,c);

    greenField = new JTextField(2);
    c.fill = GridBagConstraints.VERTICAL;
    c.weightx = 0.0;
    c.gridx = 1;
    c.gridy = 1;
    colorPanel.add(greenField,c);

    blueField = new JTextField(2);
    c.fill = GridBagConstraints.VERTICAL;
    c.weightx = 0.5;
    c.gridx = 1;
    c.gridy = 2;
    colorPanel.add(blueField,c);

    redField.addActionListener(this);
    greenField.addActionListener(this);
    blueField.addActionListener(this);



    this.add(colorPanel, BorderLayout.EAST);
}


public void actionPerformed(ActionEvent arg0) {
    redInt = Integer.parseInt(redField.getText());
    greenInt = Integer.parseInt(greenField.getText());
    blueInt = Integer.parseInt(blueField.getText());

    // creates the color icon. It works sometimes, but not every time.
    color = new JLabel(new ColorIcon(redInt,greenInt,blueInt));
    buttonPanel.add(color);
    print(redInt,greenInt, blueInt);

}


private void print(int a, int b, int c)
{
    // just to see if the actionperformed() method works.
    System.out.println(a);
    System.out.println(b);
    System.out.println(c);
}


public Dimension getPreferredSize() {
    return new Dimension(300,300);
}


public static void main(String[] args)
{
    ColorFrame frame = new ColorFrame(200,200); 
}


}

Color Icon class:

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;

import javax.swing.Icon;


public class ColorIcon implements Icon{



private final int size = 30;
private int red;
private int green;
private int blue;



public ColorIcon(int r, int g, int b)
{
    this.red = r;
    this.green = g;
    this.blue = b;
}


@Override
public int getIconHeight() {
    // TODO Auto-generated method stub
    return size;
}

@Override
public int getIconWidth() {
    // TODO Auto-generated method stub
    return size;
}

@Override
public void paintIcon(Component c, Graphics g, int x, int y) {
    // TODO Auto-generated method stub

    Graphics2D g2 = (Graphics2D) g;
    Rectangle2D.Double square = new Rectangle2D.Double(50, 50, size, size);
    g2.setColor(new Color(red,green,blue));
    g2.fill(square);
}

}

Answer 1

There are a number of possible ways you can handle this. One is to create a panel where you can set the color and paint the entire panel. Something like

private class ColorPanel extends JPanel {
    private Color color = Color.BLUE;

    public void setColor(Color color) {
        this.color = color;
        repaint();
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(color);
        g.fillRect(0, 0, getWidth(), getHeight());
    }

    public Dimension getPreferredSize() {
        return new Dimension(150, 150);
    }
}

You can just set the color. Another thing I noticed is that you are trying to add the new label to the button panel, but the button panel is in the south of the frame. I think you want the label in the center of the frame. So you would add the new label to the CENTER by itself, and not to the button panel.

Here's a refactor of your code.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

public class ColorFrame extends JFrame implements ActionListener {

    private JPanel colorPanel;
    private JPanel buttonPanel;

    private JLabel color;

    private JTextField redField;
    private JTextField greenField;
    private JTextField blueField;

    private JButton preview;

    private int redInt;
    private int blueInt;
    private int greenInt;

    private ColorPanel cPanel = new ColorPanel();

    public ColorFrame(int x, int y) {
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        buttonPanel = new JPanel();
        JPanel preferredSizeWrapper = new JPanel(new GridBagLayout());
        preferredSizeWrapper.add(cPanel);
        this.getContentPane().add(buttonPanel, BorderLayout.SOUTH);
        preview = new JButton("Preview Color");
        preview.addActionListener(new ButtonListener());
        buttonPanel.add(preview);
        createColorPanel();
        this.add(preferredSizeWrapper);
        this.pack();
        this.setLocation(x, y);
        this.setVisible(true);

    }

    class ButtonListener implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            // in the gui, there are three jtextfieilds that represent color
            // values. the first is red, the second is green, and the last is
            // blue.
            redInt = Integer.parseInt(redField.getText());
            greenInt = Integer.parseInt(greenField.getText());
            blueInt = Integer.parseInt(blueField.getText());
            // new ColorIcon(redInt, greenInt, blueInt)
            cPanel.setColor(new Color(redInt, greenInt, blueInt));
        }
    }

    private class ColorPanel extends JPanel {
        private Color color = Color.BLUE;

        public void setColor(Color color) {
            this.color = color;
            repaint();
        }

        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.setColor(color);
            g.fillRect(0, 0, getWidth(), getHeight());
        }

        public Dimension getPreferredSize() {
            return new Dimension(150, 150);
        }
    }

    private void createColorPanel() {
        colorPanel = new JPanel(new GridBagLayout());

        GridBagConstraints c = new GridBagConstraints();

        // creates the three textfields to input rgb values.
        // the first is r, second, b third g
        redField = new JTextField(2);
        c.fill = GridBagConstraints.VERTICAL;
        c.weightx = 0.5;
        c.gridx = 1;
        c.gridy = 0;
        c.insets = new Insets(10, 0, 0, 10);
        colorPanel.add(redField, c);

        greenField = new JTextField(2);
        c.fill = GridBagConstraints.VERTICAL;
        c.weightx = 0.0;
        c.gridx = 1;
        c.gridy = 1;
        colorPanel.add(greenField, c);

        blueField = new JTextField(2);
        c.fill = GridBagConstraints.VERTICAL;
        c.weightx = 0.5;
        c.gridx = 1;
        c.gridy = 2;
        colorPanel.add(blueField, c);

        redField.addActionListener(this);
        greenField.addActionListener(this);
        blueField.addActionListener(this);

        this.add(colorPanel, BorderLayout.EAST);
    }

    public void actionPerformed(ActionEvent arg0) {
        redInt = Integer.parseInt(redField.getText());
        greenInt = Integer.parseInt(greenField.getText());
        blueInt = Integer.parseInt(blueField.getText());

        colorPanel.add(color);

    }

    public Dimension getPreferredSize() {
        return new Dimension(300, 300);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                ColorFrame frame = new ColorFrame(200, 200);
            }
        });
    }
}

---

Another Option is just use a regular JPanel

private JPanel createCPanel() {
    return new JPanel() {
        {
            setBackground(Color.BLUE);
        }
        @Override
        public Dimension getPreferredSize() {
            return new Dimension(150, 150);
        }
    };
}

and just call setBackground(Color) on the panel. You need to keep in mind the above changes also though.

Answer 2

而不是创建颜色图标尝试使用背景颜色设置您想要的，然后设置标签的大小。