java如何在框中添加文字

public class mainFrame extends JFrame{

JLabel jl = new JLabel("用户名称:")

JTextField jtf = new JTextField()

JPanel jp_group = new JPanel()

public loginFrame() {

try {

jbInit()com.hrkj.hrkjkf.common.mysession.dataTrf.getValue("main")

} catch (Exception exception) {

exception.printStackTrace()

}

}

private void jbInit() throws Exception {

jp_group.add(jl)

jp_group.add(jl)

this.add(jtf)

this.setTitle("窗体")

this.setSize(265, 185)

}

public static void main(String[] args) {

mainFrame mf = new mainFrame()

mf.setVsible(true)

}

}

方法1、复写paint方法

public void paint(Graphics g){

g.drawString("你写的话")

}

方法2创建一个JLable 用add方法添加进去

package needl

import javax.swing.*

import java.awt.*

import java.awt.event.*

import java.awt.geom.*

import java.util.*

final class FontColor extends JFrame {

    final static private Dimension SIZE = new Dimension(800, 600)

    public String getTitle() {return "FontColor"}

    public Dimension getPreferredSize() {return SIZE}

    public Dimension getMinimumSize() {return SIZE}

    public Dimension getMaximumSize() {return SIZE}

    public Dimension getSize() {return SIZE}

    private Canvas canvas

    private Brush brush

    FontColor() throws HeadlessException {

        init()

        attachListeners()

        doLay()

        setVisible(true)

    }

    private void init() {

        brush = new StringBoundBrush()

        canvas = new Canvas(brush)

    }

    private void attachListeners() {

        addWindowListener(new WindowAdapter() {

            public void windowClosing(WindowEvent e) {

                System.exit(1)

            }

        })

    }

    private void doLay() {

        Container container = getContentPane()

        container.add(canvas, BorderLayout.CENTER)

        pack()

    }

    public static void main(String... args) {

        System.setProperty("swing.defaultlaf", "com.sun.java.swing.plaf.windows.WindowsLookAndFeel")

        SwingUtilities.invokeLater(FontColor::new)

    }

    private interface Brush extends Observer {

        /**

         * do paint action

         * @param g the graphics context in you application

         */

        void paint(Graphics g)

        /**

         * The component that this brush hold

         * @return component instance

         */

        Component getOwner()

        void setOwner(Component owner)

    }

    private static final class StringBoundBrush implements Brush {

        private Component owner

        private final static AffineTransform AFFINE_TRANSFORM = AffineTransform.getRotateInstance(45f/180f*Math.PI)

        private final static String CHAR="你好啊！"

        public StringBoundBrush() {

            AFFINE_TRANSFORM.preConcatenate(AffineTransform.getTranslateInstance(100, 100))

        }

        public Component getOwner() {

            return owner

        }

        public void setOwner(Component owner) {

            this.owner = owner

        }

        public void paint(Graphics g) {

            Graphics2D g2 = (Graphics2D)g.create()

            g2.setTransform(AFFINE_TRANSFORM)

            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON)

            g2.setColor(Color.PINK)

            g2.setFont(g2.getFont().deriveFont(34f))

            g2.fill( g2.getFontMetrics().getStringBounds(CHAR,g2) )

            g2.setColor(Color.BLUE)

            g2.drawString(CHAR,0,0)

            g2.dispose()

        }

        public void update(Observable o, Object arg) {

            if (owner != null) owner.repaint()

        }

    }

    /**

     * you canvas

     */

    private class Canvas extends JComponent {

        private Brush brush

        private Canvas(Brush brush) {

            super()

            this.brush = brush

            brush.setOwner(this)

        }

        protected void paintComponent(Graphics g) {

            super.paintComponent(g)

            if (brush == null) return

            brush.paint(g)

        }

    }

}

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