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谁能解释在框架上绘制图形的正确方法?我查看了其他示例,这应该有效,但它没有。请参阅“绘画”方法。我试图画一个正方形(矩形),但它没有出现在我的框架上。

问候

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Colors extends javax.swing.JFrame {

    public Colors() {
        initComponents();
        addSliderListeners();
        addSliderLabels();
    }
    public void Paint(Graphics g){
        Graphics2D g2 = (Graphics2D)g;
        g2.setColor(Color.BLUE);
        g2.draw(new Rectangle(25,25,200,200));
    }
    private void addSliderListeners(){
        sliderRed.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
                updateImage();
            }
        });
        sliderGreen.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
                updateImage();
            }
        });
        sliderBlue.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
                updateImage();
            }
        });
    }

    private void updateImage(){
        lblRedDec.setText(""+sliderRed.getValue());
        lblRedDec.setForeground(new Color(sliderRed.getValue(),0,0));
        lblRedHex.setText(Integer.toHexString(sliderRed.getValue()));
        lblRedHex.setForeground(lblRedDec.getForeground());
//Color textColor = new Color(    255-lblRedDec.getForeground().getRed(),
//                                255-lblRedDec.getForeground().getGreen(),
//                                255-lblRedDec.getForeground().getBlue()
//                            );
//jLabel1.setBackground(textColor);

        lblGreenDec.setText(""+sliderGreen.getValue());
        lblGreenDec.setForeground(new Color(0,sliderGreen.getValue(),0));
        lblGreenHex.setText(Integer.toHexString(sliderGreen.getValue()));
        lblGreenHex.setForeground(lblGreenDec.getForeground());

        lblBlueDec.setText(""+sliderBlue.getValue());
        lblBlueHex.setText(Integer.toHexString(sliderBlue.getValue()));
        lblBlueDec.setForeground(new Color(0,0,sliderBlue.getValue()));
        lblBlueHex.setForeground(lblBlueDec.getForeground());

    }

    private void addSliderLabels() {
        sliderRed.setPaintLabels(true);
        sliderGreen.setPaintLabels(true);
        sliderBlue.setPaintLabels(true);
    }
/**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        sliderRed = new javax.swing.JSlider();
        lblRed = new javax.swing.JLabel();
        lblRedHex = new javax.swing.JLabel();
        lblRedDec = new javax.swing.JLabel();
        sliderGreen = new javax.swing.JSlider();
        lblGreen = new javax.swing.JLabel();
        lblGreenHex = new javax.swing.JLabel();
        lblGreenDec = new javax.swing.JLabel();
        sliderBlue = new javax.swing.JSlider();
        lblBlue = new javax.swing.JLabel();
        lblBlueHex = new javax.swing.JLabel();
        lblBlueDec = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setResizable(false);

        sliderRed.setMajorTickSpacing(15);
        sliderRed.setMaximum(255);
        sliderRed.setMinorTickSpacing(5);
        sliderRed.setOrientation(javax.swing.JSlider.VERTICAL);
        sliderRed.setPaintTicks(true);
        sliderRed.setSnapToTicks(true);
        sliderRed.setToolTipText("");
        sliderRed.setValue(212);
        sliderRed.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
        sliderRed.setName(""); // NOI18N

        lblRed.setText("Red");

        lblRedHex.setText("hex");

        lblRedDec.setText("dec");

        sliderGreen.setMajorTickSpacing(15);
        sliderGreen.setMaximum(255);
        sliderGreen.setMinorTickSpacing(5);
        sliderGreen.setOrientation(javax.swing.JSlider.VERTICAL);
        sliderGreen.setPaintTicks(true);
        sliderGreen.setSnapToTicks(true);
        sliderGreen.setToolTipText("");
        sliderGreen.setValue(35);
        sliderGreen.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
        sliderGreen.setName(""); // NOI18N

        lblGreen.setText("Green");

        lblGreenHex.setText("hex");

        lblGreenDec.setText("dec");

        sliderBlue.setMajorTickSpacing(15);
        sliderBlue.setMaximum(255);
        sliderBlue.setMinorTickSpacing(5);
        sliderBlue.setOrientation(javax.swing.JSlider.VERTICAL);
        sliderBlue.setPaintTicks(true);
        sliderBlue.setSnapToTicks(true);
        sliderBlue.setToolTipText("");
        sliderBlue.setValue(218);
        sliderBlue.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
        sliderBlue.setName(""); // NOI18N

        lblBlue.setText("Blue");

        lblBlueHex.setText("hex");

        lblBlueDec.setText("dec");

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(lblRedHex)
                            .addComponent(lblRed)
                            .addComponent(lblRedDec))
                        .addGap(25, 25, 25))
                    .addGroup(layout.createSequentialGroup()
                        .addGap(26, 279, Short.MAX_VALUE)
                        .addComponent(sliderRed, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(sliderGreen, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(lblGreenHex)
                            .addComponent(lblGreen)
                            .addComponent(lblGreenDec))
                        .addGap(25, 25, 25)))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(sliderBlue, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(lblBlueHex)
                            .addComponent(lblBlue)
                            .addComponent(lblBlueDec))
                        .addGap(25, 25, 25)))
                .addGap(6, 6, 6))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(lblBlueDec)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(lblBlueHex)
                        .addGap(18, 18, 18)
                        .addComponent(lblBlue)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(sliderBlue, javax.swing.GroupLayout.PREFERRED_SIZE, 285, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(lblGreenDec)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(lblGreenHex)
                        .addGap(18, 18, 18)
                        .addComponent(lblGreen)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(sliderGreen, javax.swing.GroupLayout.PREFERRED_SIZE, 285, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(lblRedDec)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(lblRedHex)
                        .addGap(16, 16, 16)
                        .addComponent(lblRed)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(sliderRed, javax.swing.GroupLayout.PREFERRED_SIZE, 285, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap())
        );

        pack();
    }// </editor-fold>


    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Colors.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Colors.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Colors.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Colors.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Colors().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JLabel lblBlue;
    private javax.swing.JLabel lblBlueDec;
    private javax.swing.JLabel lblBlueHex;
    private javax.swing.JLabel lblGreen;
    private javax.swing.JLabel lblGreenDec;
    private javax.swing.JLabel lblGreenHex;
    private javax.swing.JLabel lblRed;
    private javax.swing.JLabel lblRedDec;
    private javax.swing.JLabel lblRedHex;
    private javax.swing.JSlider sliderBlue;
    private javax.swing.JSlider sliderGreen;
    private javax.swing.JSlider sliderRed;
    // End of variables declaration

}
4

2 回答 2

1

它是油漆(带有小写“p”)

于 2012-11-16T09:38:27.020 回答
0

正如CAMOBAB在评论中所说

在此方法之前更改public void Paint(Graphics g)public void paint(Graphics g)添加注释@Override

于 2013-05-21T16:58:42.503 回答