用滑动条实现RGB调色板功能

package GUI;
import javax.swing.;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.;
public class RGBPalette {
public JFrame jf;
public JPanel jp, jp_R, jp_G, jp_B, jp_Label;
public JLabel jLabel_R, jLabel_G, jLabel_B, jLabel_BG, jLabel_Rt, jLabel_Gt, jLabel_Bt;
public JSlider jSlider_R, jSlider_G, jSlider_B;
public int r, g, b;

public RGBPalette(){

    jf = new JFrame("RGB调色板");
    jf.setSize(300, 250);
    jf.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    jf.setLocationRelativeTo(null);
    jf.setResizable(false);

    jp = new JPanel(new FlowLayout());
    jp_R = new JPanel(new FlowLayout());
    jp_G = new JPanel(new FlowLayout());
    jp_B = new JPanel(new FlowLayout());
    jp_Label = new JPanel(new GridLayout(1,3,5,5));

    jp_R = new JPanel(new FlowLayout());
    jp_G = new JPanel(new FlowLayout());
    jp_B = new JPanel(new FlowLayout());

    jLabel_R = new JLabel("Red~~");
    jLabel_G = new JLabel("Green");
    jLabel_B = new JLabel("Blue~");
    jLabel_Rt = new JLabel("R: 255");
    jLabel_Gt = new JLabel("G: 255");
    jLabel_Bt = new JLabel("B: 255");
    jLabel_BG = new JLabel("#000000");
    jLabel_Rt.setFont(new Font(null, Font.PLAIN, 24));
    jLabel_Gt.setFont(new Font(null, Font.PLAIN, 24));
    jLabel_Bt.setFont(new Font(null, Font.PLAIN, 24));
    jLabel_BG.setFont(new Font(null, Font.PLAIN, 40));
    jLabel_BG.setBackground(new Color(255, 255, 255));
    jLabel_BG.setOpaque(true);

    jSlider_R = new JSlider(0,255,255);
    jSlider_G = new JSlider(0,255,255);
    jSlider_B = new JSlider(0,255,255);

    RGBListener listener = new RGBListener();

    jSlider_R.addChangeListener(listener);
    jSlider_G.addChangeListener(listener);
    jSlider_B.addChangeListener(listener);

    jp_R.add(jLabel_R);
    jp_R.add(jSlider_R);

    jp_G.add(jLabel_G);
    jp_G.add(jSlider_G);

    jp_B.add(jLabel_B);
    jp_B.add(jSlider_B);

    jp_Label.add(jLabel_Rt);
    jp_Label.add(jLabel_Gt);
    jp_Label.add(jLabel_Bt);

    jp.add(jp_R);
    jp.add(jp_G);
    jp.add(jp_B);
    jp.add(jLabel_BG);
    jp.add(jp_Label);

    jf.setContentPane(jp);
    jf.setVisible(true);

}

class RGBListener implements ChangeListener{

    @Override
    public void stateChanged(ChangeEvent changeEvent) {
        r = jSlider_R.getValue();
        g = jSlider_G.getValue();
        b = jSlider_B.getValue();
        jLabel_Rt.setText("R: " + r);
        jLabel_Gt.setText("G: " + g);
        jLabel_Bt.setText("B: " + b);
        jLabel_BG.setText(convertRGBToHex(r, g, b));
        jLabel_BG.setBackground(new Color(r, g, b));
        jLabel_BG.setForeground(new Color(255 - r, 255 - g, 255 - b));
    }
}

//**将rgb色彩值转成16进制代码**
//**来自CSDN https://blog.csdn.net/Jason763/article/details/72844092 **

public  String convertRGBToHex(int r, int g, int b) {
    String rFString, rSString, gFString, gSString, bFString, bSString, result;
    int red, green, blue;
    int r_red, r_green, r_blue;
    red = r / 16;
    r_red = r % 16;
    if (red == 10) rFString = "A";
    else if (red == 11) rFString = "B";
    else if (red == 12) rFString = "C";
    else if (red == 13) rFString = "D";
    else if (red == 14) rFString = "E";
    else if (red == 15) rFString = "F";
    else rFString = String.valueOf(red);

    if (r_red == 10) rSString = "A";
    else if (r_red == 11) rSString = "B";
    else if (r_red == 12) rSString = "C";
    else if (r_red == 13) rSString = "D";
    else if (r_red == 14) rSString = "E";
    else if (r_red == 15) rSString = "F";
    else rSString = String.valueOf(r_red);

    rFString = rFString + rSString;

    green = g / 16;
    r_green = g % 16;

    if (green == 10) gFString = "A";
    else if (green == 11) gFString = "B";
    else if (green == 12) gFString = "C";
    else if (green == 13) gFString = "D";
    else if (green == 14) gFString = "E";
    else if (green == 15) gFString = "F";
    else gFString = String.valueOf(green);

    if (r_green == 10) gSString = "A";
    else if (r_green == 11) gSString = "B";
    else if (r_green == 12) gSString = "C";
    else if (r_green == 13) gSString = "D";
    else if (r_green == 14) gSString = "E";
    else if (r_green == 15) gSString = "F";
    else gSString = String.valueOf(r_green);

    gFString = gFString + gSString;

    blue = b / 16;
    r_blue = b % 16;

    if (blue == 10) bFString = "A";
    else if (blue == 11) bFString = "B";
    else if (blue == 12) bFString = "C";
    else if (blue == 13) bFString = "D";
    else if (blue == 14) bFString = "E";
    else if (blue == 15) bFString = "F";
    else bFString = String.valueOf(blue);

    if (r_blue == 10) bSString = "A";
    else if (r_blue == 11) bSString = "B";
    else if (r_blue == 12) bSString = "C";
    else if (r_blue == 13) bSString = "D";
    else if (r_blue == 14) bSString = "E";
    else if (r_blue == 15) bSString = "F";
    else bSString = String.valueOf(r_blue);
    bFString = bFString + bSString;
    result = "#" + rFString + gFString + bFString;
    return result;

}

public static void main (String[] args){
    new RGBPalette();
}

}