Java學習之旅1
阿新 • • 發佈：2019-01-06
1.圓角按鈕的設定
import java.awt.AlphaComposite; import java.awt.Color; import java.awt.Font; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.Shape; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.geom.RoundRectangle2D; import javax.swing.JButton; public class RButton extends JButton { private static final long serialVersionUID = 39082560987930759L; public static final Color BUTTON_COLOR1 = new Color(250, 160, 122); public static final Color BUTTON_COLOR2 = new Color(255, 0, 0); // public static final Color BUTTON_COLOR1 = new Color(125, 161, 237); // public static final Color BUTTON_COLOR2 = new Color(91, 118, 173); public static final Color BUTTON_FOREGROUND_COLOR = Color.WHITE; private boolean hover; public RButton(String name) { this.setText(name); setFont(new Font("system", Font.PLAIN, 12));//字型格式 setBorderPainted(false);//無邊框 setForeground(BUTTON_COLOR2); setFocusPainted(false);//隱藏按鈕focus邊框 setContentAreaFilled(false);//按鈕透明 addMouseListener(new MouseAdapter() { @Override public void mouseEntered(MouseEvent e) {//新增滑鼠進入監聽 setForeground(BUTTON_FOREGROUND_COLOR); hover = true; repaint(); } @Override public void mouseExited(MouseEvent e) {//新增滑鼠離開監聽 setForeground(BUTTON_COLOR2); hover = false; repaint(); } }); } @Override protected void paintComponent(Graphics g) {//重繪button產生圓角 Graphics2D g2d = (Graphics2D) g.create(); int h = getHeight(); int w = getWidth(); float tran = 1F; if (!hover) { tran = 0.3F; } g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); GradientPaint p1; GradientPaint p2; if (getModel().isPressed()) { p1 = new GradientPaint(0, 0, new Color(0, 0, 0), 0, h - 1, new Color(100, 100, 100)); p2 = new GradientPaint(0, 1, new Color(0, 0, 0, 50), 0, h - 3, new Color(255, 255, 255, 100)); } else { p1 = new GradientPaint(0, 0, new Color(100, 100, 100), 0, h - 1, new Color(0, 0, 0)); p2 = new GradientPaint(0, 1, new Color(255, 255, 255, 100), 0, h - 3, new Color(0, 0, 0, 50)); } g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, tran)); RoundRectangle2D.Float r2d = new RoundRectangle2D.Float(0, 0, w - 1, h - 1, 20, 20); Shape clip = g2d.getClip(); g2d.clip(r2d); GradientPaint gp = new GradientPaint(0.0F, 0.0F, BUTTON_COLOR1, 0.0F, h, BUTTON_COLOR2, true); g2d.setPaint(gp); g2d.fillRect(0, 0, w, h); g2d.setClip(clip); g2d.setPaint(p1); g2d.drawRoundRect(0, 0, w - 1, h - 1, 20, 20); g2d.setPaint(p2); g2d.drawRoundRect(1, 1, w - 3, h - 3, 18, 18); g2d.dispose(); super.paintComponent(g); } }
2.標籤Jlabel文字自動換行方法：
Jlabel jl=new Jlabel(string);
string 字串的首尾新增…標籤，則自動換行；
如：
JLabel jlabel2 = new JLabel("<html>鋤禾日當午，汗滴禾下土。誰知盤中餐，粒粒皆辛苦。</html>");
而在字串中新增
會在該處強制換行：
JLabel jlabel2 = new JLabel("<html>鋤禾日當午，<br>汗滴禾下土。<br>誰知盤中餐，<br>粒粒皆辛苦。</html>");
輸出標籤結果：
鋤禾日當午，
汗滴禾下土。
誰知盤中餐，
粒粒皆辛苦。
3.視窗設定背景圖片方法（JDialog同樣）
import java.awt.Graphics; import java.awt.Image; import java.net.URL; import javax.swing.ImageIcon; import javax.swing.JPanel; public class PictureJPanel extends JPanel { public URL picture;// 圖片位置 public PictureJPanel(URL s1) { this.picture = s1; } @Override public void paintComponent(Graphics g) { ImageIcon image = new ImageIcon(picture); image.setImage( image.getImage().getScaledInstance(this.getWidth(), this.getHeight(), Image.SCALE_AREA_AVERAGING));// 這裡設定圖片的大小和視窗的大小相等 g.drawImage(image.getImage(), 0, 0, this);// 在視窗上畫出該圖片 }} } }
在窗體中呼叫該方法可完成背景圖片的設定
import java.net.URL;
import javax.swing.JFrame;
public class PictureFrame extends JFrame {
public PictureFrame() {
setBounds(0, 0, 1000, 500);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setUndecorated(true);// 設定出去窗體右上角最大化、最小化、關閉按鈕
URL url = PictureFrame.class.getResource("/416690300862016439.png");
PictureJPanel pj = new PictureJPanel(url);
add(pj);
setVisible(true);
}
public static void main(String[] args) {
PictureFrame pf = new PictureFrame();
}
}