java - 使用滚动条或微调器的值设置 FillRect() 的颜色

Question

我创建了两个 JPanel 并将它们添加到 mainpanel 上，然后将这个 JPanel 添加到 JFrame。我无法使用微调器或滚动条的更改值来设置矩形的颜色。如果有人有解决方案，请帮助我解决这个问题。

TestColorFrame.java

import java.awt.BorderLayout;
import java.awt.GridLayout;import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.plaf.metal.MetalLookAndFeel;
import com.swing.Myframe;

public class TestColorFrame extends JFrame {

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
        } catch (ClassNotFoundException | InstantiationException
                | IllegalAccessException | UnsupportedLookAndFeelException e) {
            e.printStackTrace();
        }
        JFrame f = new JFrame();
        JPanel Mainpanel = new JPanel(new GridLayout(2, 1));

        ColorPanel1 p = new ColorPanel1();
        ColorPanel2 p1 = new ColorPanel2();

        //f.getContentPane().setLayout(new BorderLayout() );
        f.add(Mainpanel);

        Mainpanel.add(p);
        Mainpanel.add(p1,BorderLayout.SOUTH);

        f.setVisible(true);
        f.setResizable(false);
        f.setSize(500,500);
        f.setTitle("My Color Frame");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
    }
}

ColorPanel1.java

import java.awt.Adjustable;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import javax.swing.JColorChooser;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.JSpinner;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SpinnerModel;
import javax.swing.SpinnerNumberModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class ColorPanel1 extends JPanel implements
                    AdjustmentListener,ChangeListener { 
    ColorPanel2 p;
    private JLabel jLabelred,jLabelgreen,jLabelblue;

    public JScrollBar jRedScrollbar,jGreenScollbar,jBlueScrollbar;
    //private JTextField jRedtext,jGreentext,jBluetext;
    protected JSpinner jRed, jGreen, jBlue;
    ColorPanel2 color2;
    public Color current;

    public ColorPanel1() {
        setLayout(new GridLayout(3, 3,60,60));
        jLabelred = new JLabel("RED");
        add(jLabelred);

        SpinnerModel spinnerModel = new SpinnerNumberModel(100, 0, 255, 1) ;
        jRed = new JSpinner(spinnerModel);
        add(jRed); 
        jRedScrollbar = new JScrollBar(JScrollBar.HORIZONTAL, 100, 40, 0, 255);
        add(jRedScrollbar);

        jLabelgreen = new JLabel("GREEN");
        add(jLabelgreen);
        SpinnerModel spinnerModel1 = new SpinnerNumberModel(200, 0, 255, 1);
        jGreen = new JSpinner(spinnerModel1);
        add(jGreen);

        jGreenScollbar = new JScrollBar(JScrollBar.HORIZONTAL, 200, 4, 0, 255);
        add(jGreenScollbar);

        jLabelblue = new JLabel("BLUE");
        add(jLabelblue);
        SpinnerModel spinnerModel2 = new SpinnerNumberModel(50, 0, 255, 1);
        jBlue = new JSpinner(spinnerModel2);
        add(jBlue);

        jBlueScrollbar = new JScrollBar(JScrollBar.HORIZONTAL, 50, 40, 0, 255);
        add(jBlueScrollbar);

        jRedScrollbar.addAdjustmentListener(this);
        jBlueScrollbar.addAdjustmentListener(this);
        jGreenScollbar.addAdjustmentListener(this);
        spinnerModel.addChangeListener(this);
        spinnerModel1.addChangeListener(this);
        spinnerModel2.addChangeListener(this);
    }

    @Override
    public void adjustmentValueChanged(AdjustmentEvent e) {
        int r = jRedScrollbar.getValue();
        int g = jGreenScollbar.getValue();
        int b = jBlueScrollbar.getValue();

        jRed.setValue(jRedScrollbar.getValue()); 
        jBlue.setValue(jBlueScrollbar.getValue());
        jGreen.setValue(jGreenScollbar.getValue());
    }

    @Override
    public void stateChanged(ChangeEvent e) {
        SpinnerModel spinnerModel = jRed.getModel();
        if (spinnerModel instanceof SpinnerModel) {
            jRedScrollbar.setValue((int) spinnerModel.getValue());
        }
        SpinnerModel spinnerModel1 = jGreen.getModel();
        if(spinnerModel1 instanceof SpinnerModel) {
            jGreenScollbar.setValue((int) jGreen.getValue());
        }
        SpinnerModel spinnerModel2 = jBlue.getModel();
        if(spinnerModel2 instanceof SpinnerModel) {
            jBlueScrollbar.setValue((int) jBlue.getValue());
        }           
    } 
}

ColorPanel2.java

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SpinnerModel;
import javax.swing.SpinnerNumberModel;

public class ColorPanel2 extends JPanel {

    private JColorChooser colorchooser;
    ColorPanel1 color=new ColorPanel1();

    public ColorPanel2() {
        setLayout(new BorderLayout());
    }

    public void paintComponent(Graphics graphics) {   
        super.paintComponent(graphics);
        int r = (int) color.jRed.getValue();
        int g = (int) color.jGreen.getValue();
        int b = (int) color.jBlue.getValue();
        graphics.setColor(new Color(r,g,b));
        graphics.fillRect(100, 50, 300, 150);
    } 
}

Answer 1

您的ColorPanel 类中需要一个类成员Color。并且还有一个二传手。在 setter 中，调用 repaint()。在您的 paintComponent 方法中，使用类成员 Color 而不是创建 new Color()。有点像

public class ColorPanel extends JPanel {
    private Color color;

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

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        ...
        g.setColor(color);
    }
}

当您在ColorPanel 上setColor 并传递新颜色时，面板将使用更新后的颜色重新绘制。

这是一个完整的例子

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;


public class TestColorFrame {

    private static final int DEFAULT_VALUE = 100;

    private JSpinner rSpinner;
    private JSpinner gSpinner;
    private JSpinner bSpinner;
    private ColorPanel colorPanel;

    public TestColorFrame() {
        colorPanel = new ColorPanel();

        rSpinner = createRGBSpinner();
        gSpinner = createRGBSpinner();
        bSpinner = createRGBSpinner();

        JPanel spinnerPanel = new JPanel();
        spinnerPanel.add(new JLabel("R"));
        spinnerPanel.add(rSpinner);
        spinnerPanel.add(new JLabel("G"));
        spinnerPanel.add(gSpinner);
        spinnerPanel.add(new JLabel("B"));
        spinnerPanel.add(bSpinner);

        JFrame frame = new JFrame("Color Spinners");
        frame.add(colorPanel);
        frame.add(spinnerPanel, BorderLayout.NORTH);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

    }

    private JSpinner createRGBSpinner() {
        SpinnerNumberModel model = new SpinnerNumberModel(DEFAULT_VALUE, 0, 255, 1);
        JSpinner spinner = new JSpinner(model);
        spinner.addChangeListener(new ChangeListener(){
            public void stateChanged(ChangeEvent e) {
                int[] values =  getModelValues();
                colorPanel.setColor(new Color(values[0], values[1], values[2]));
            }
        });
        return spinner;
    }

    private int[] getModelValues() {
        int r = (Integer)((SpinnerNumberModel)rSpinner.getModel()).getValue();
        int g = (Integer)((SpinnerNumberModel)gSpinner.getModel()).getValue();
        int b = (Integer)((SpinnerNumberModel)bSpinner.getModel()).getValue();
        return new int[] {r, g, b};
    }

    class ColorPanel extends JPanel {
        private Color color = new Color(DEFAULT_VALUE, DEFAULT_VALUE, DEFAULT_VALUE);

        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());
        }

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

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                new TestColorFrame();
            }
        });
    }
}

---

此外，您可能应该考虑使用 JSlider ，这似乎比使用 JScrollBar 进行值调整更自然

---

更新

重构

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JSpinner;
import javax.swing.SpinnerModel;
import javax.swing.SpinnerNumberModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class TestColorFrame extends JFrame {

    public static void main(String[] args) {
        JFrame f = new JFrame();
        JPanel Mainpanel = new JPanel(new GridLayout(2, 1));


        ColorPanel2 p1 = new ColorPanel2();
        ColorPanel1 p = new ColorPanel1(p1);

        //f.getContentPane().setLayout(new BorderLayout() );
        f.add(Mainpanel);

        Mainpanel.add(p);
        Mainpanel.add(p1, BorderLayout.SOUTH);

        f.setVisible(true);
        f.setResizable(false);
        f.setSize(500, 500);
        f.setTitle("My Color Frame");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

class ColorPanel1 extends JPanel implements
        AdjustmentListener, ChangeListener {
    private JLabel jLabelred, jLabelgreen, jLabelblue;

    public JScrollBar jRedScrollbar, jGreenScollbar, jBlueScrollbar;
    //private JTextField jRedtext,jGreentext,jBluetext;
    protected JSpinner jRed, jGreen, jBlue;
    ColorPanel2 colorPanel2;
    public Color current;

    public ColorPanel1(ColorPanel2 colorPanel2) {
        this.colorPanel2 = colorPanel2;
        setLayout(new GridLayout(3, 3, 60, 60));
        jLabelred = new JLabel("RED");
        add(jLabelred);

        SpinnerModel spinnerModel = new SpinnerNumberModel(100, 0, 255, 1);
        jRed = new JSpinner(spinnerModel);
        add(jRed);
        jRedScrollbar = new JScrollBar(JScrollBar.HORIZONTAL, 100, 40, 0, 255);
        add(jRedScrollbar);

        jLabelgreen = new JLabel("GREEN");
        add(jLabelgreen);
        SpinnerModel spinnerModel1 = new SpinnerNumberModel(200, 0, 255, 1);
        jGreen = new JSpinner(spinnerModel1);
        add(jGreen);

        jGreenScollbar = new JScrollBar(JScrollBar.HORIZONTAL, 200, 4, 0, 255);
        add(jGreenScollbar);

        jLabelblue = new JLabel("BLUE");
        add(jLabelblue);
        SpinnerModel spinnerModel2 = new SpinnerNumberModel(50, 0, 255, 1);
        jBlue = new JSpinner(spinnerModel2);
        add(jBlue);

        jBlueScrollbar = new JScrollBar(JScrollBar.HORIZONTAL, 50, 40, 0, 255);
        add(jBlueScrollbar);

        jRedScrollbar.addAdjustmentListener(this);
        jBlueScrollbar.addAdjustmentListener(this);
        jGreenScollbar.addAdjustmentListener(this);
        spinnerModel.addChangeListener(this);
        spinnerModel1.addChangeListener(this);
        spinnerModel2.addChangeListener(this);
    }

    @Override
    public void adjustmentValueChanged(AdjustmentEvent e) {
        int r = jRedScrollbar.getValue();
        int g = jGreenScollbar.getValue();
        int b = jBlueScrollbar.getValue();

        jRed.setValue(jRedScrollbar.getValue());
        jBlue.setValue(jBlueScrollbar.getValue());
        jGreen.setValue(jGreenScollbar.getValue());
        setNewPanelColor();
    }

    @Override
    public void stateChanged(ChangeEvent e) {
        SpinnerModel spinnerModel = jRed.getModel();
        if (spinnerModel instanceof SpinnerModel) {
            jRedScrollbar.setValue((int) spinnerModel.getValue());
            setNewPanelColor();
        }
        SpinnerModel spinnerModel1 = jGreen.getModel();
        if (spinnerModel1 instanceof SpinnerModel) {
            jGreenScollbar.setValue((int) jGreen.getValue());
            setNewPanelColor();
        }
        SpinnerModel spinnerModel2 = jBlue.getModel();
        if (spinnerModel2 instanceof SpinnerModel) {
            jBlueScrollbar.setValue((int) jBlue.getValue());
            setNewPanelColor();
        }
    }

    public void setNewPanelColor() {
        int r = (int)((SpinnerModel)jRed.getModel()).getValue();
        int g = (int)((SpinnerModel)jGreen.getModel()).getValue();
        int b = (int)((SpinnerModel)jBlue.getModel()).getValue();
        colorPanel2.setColor(new Color(r, g, b));
    }
}

class ColorPanel2 extends JPanel {

    private JColorChooser colorchooser;
    private Color color = new Color(100, 200, 50);

    public ColorPanel2() {
        setLayout(new BorderLayout());
    }

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

    @Override
    public void paintComponent(Graphics graphics) {
        super.paintComponent(graphics);

        graphics.setColor(color);
        graphics.fillRect(100, 50, 300, 150);
    }
}