Java Swing为基本音乐播放器绘制PlayButton

也许我的情况是一个简单的想法混乱。 如何使用Shape绘制这样的按钮？

我不介意圆角，inheritance我的圆角按钮。

import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.Shape; import java.awt.geom.RoundRectangle2D; import javax.swing.AbstractButton; import javax.swing.ButtonModel; import javax.swing.JComponent; import javax.swing.plaf.basic.BasicButtonUI; public class PlayButtonUI extends BasicButtonUI{ protected Shape shape; @Override protected void installDefaults(AbstractButton b) { super.installDefaults(b); b.setOpaque(false);//removes that annoying default background } @Override public void paint(Graphics g, JComponent c) { Graphics2D g2 = (Graphics2D)g; AbstractButton b = (AbstractButton) c; ButtonModel model = b.getModel(); drawButtonShape(b); g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);//smoth borders if(model.isArmed()) { g2.setColor(Color.RED);//color when button is pressed }else{ g2.setColor(Color.GREEN);//default button color } g2.fill(shape);//aplying color super.paint(g2, c); } private void drawButtonShape(JComponent c) { //button shape is drawn here, 16 are the border radius shape = new RoundRectangle2D.Float(0, 0, c.getWidth()-1, c.getHeight()-1,16, 16); } } 

我真的不知道如何绘制任何东西，这个类是我在某个地方发现的一个混乱的例子的结果，然后我自己简化直到它工作，我留下了重要的一些评论。

我一直在寻找，并在oracle文档中找到了这个例子。 https://docs.oracle.com/javase/tutorial/2d/geometry/arbitrary.html

我真的不知道如何将Graphics2D转换为Shape，请告诉我，如果我采取了错误的方式，谢谢。

Answer 1

所以，我花了一天时间更好地对抗这个问题，尝试做一大堆魔术……我甚至不能做简单的卡片技巧：P

然后我意识到，还有其他技巧我可以做…

 import java.awt.BasicStroke; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.Shape; import java.awt.geom.GeneralPath; import javax.swing.AbstractButton; import javax.swing.ButtonModel; import javax.swing.JButton; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.SwingUtilities; import javax.swing.plaf.basic.BasicButtonUI; public class Test { public static void main(String[] args) { new Test(); } public Test() { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { JFrame frame = new JFrame(); JButton btn = new JButton(); btn.setUI(new PlayButtonUI()); frame.add(btn); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class PlayButtonUI extends BasicButtonUI { @Override public Dimension getPreferredSize(JComponent c) { return new Dimension(200, 200); } @Override public void paint(Graphics g, JComponent c) { Graphics2D g2 = (Graphics2D) g; AbstractButton b = (AbstractButton) c; ButtonModel model = b.getModel(); g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);//smoth borders if (model.isArmed()) { g2.setColor(Color.BLACK);//color when button is pressed } else { g2.setColor(Color.GRAY);//default button color } float thinkness = Math.min(c.getWidth(), c.getHeight()) * 0.1f; Shape shape = shapeFor(c, thinkness); g2.setStroke(new BasicStroke(thinkness, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND)); g2.fill(shape);//aplying color g2.draw(shape); super.paint(g2, c); } private Shape shapeFor(JComponent c, float thickness) { GeneralPath gp = new GeneralPath(); double width = c.getWidth(); double height = c.getHeight(); double vPos = height / 2.0; double hPos = width - thickness; gp.moveTo(0.0 + thickness, 0.0 + thickness); gp.lineTo(hPos, vPos); gp.lineTo(0.0 + thickness, height - thickness); gp.closePath(); return gp; } } } 

所以，这是一个轻微的“欺骗”。 这实际上做的是使用Stroke的属性来生成圆边，而不是尝试使用curveTo或复合形状

有关更多详细信息，请查看Stroking和Filling Graphics Primitives