Java 做一个圆形按钮
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/778222/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Make a button round
提问by
I'm trying to make a JButton round at the (x,y) coordinates of (150,210). I want the button to be an oval of the size (40,40). And the buttons background color red. It doesn't need text, so I should get a button to whatever size I want, right?
我正在尝试在 (150,210) 的 (x,y) 坐标处制作一个 JButton。我希望按钮是大小为 (40,40) 的椭圆形。按钮背景颜色为红色。它不需要文本，所以我应该得到一个我想要的任何大小的按钮，对吗？
I am using a panel, and I set the setLayout to null:
我正在使用面板，并将 setLayout 设置为 null：
setLayout(null)
I checked Google, and it brought me here. How can I do this?
我查了谷歌，它把我带到了这里。我怎样才能做到这一点？
回答by Adam Davis
JDC Tech Tips: August 26, 1999: Creating Round Swing Buttons
JDC 技术提示：1999 年 8 月 26 日：创建圆形摆动按钮
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
public class RoundButton extends JButton {
public RoundButton(String label) {
super(label);
// These statements enlarge the button so that it
// becomes a circle rather than an oval.
Dimension size = getPreferredSize();
size.width = size.height = Math.max(size.width,
size.height);
setPreferredSize(size);
// This call causes the JButton not to paint
// the background.
// This allows us to paint a round background.
setContentAreaFilled(false);
}
// Paint the round background and label.
protected void paintComponent(Graphics g) {
if (getModel().isArmed()) {
// You might want to make the highlight color
// a property of the RoundButton class.
g.setColor(Color.lightGray);
} else {
g.setColor(getBackground());
}
g.fillOval(0, 0, getSize().width-1,
getSize().height-1);
// This call will paint the label and the
// focus rectangle.
super.paintComponent(g);
}
// Paint the border of the button using a simple stroke.
protected void paintBorder(Graphics g) {
g.setColor(getForeground());
g.drawOval(0, 0, getSize().width-1,
getSize().height-1);
}
// Hit detection.
Shape shape;
public boolean contains(int x, int y) {
// If the button has changed size,
// make a new shape object.
if (shape == null ||
!shape.getBounds().equals(getBounds())) {
shape = new Ellipse2D.Float(0, 0,
getWidth(), getHeight());
}
return shape.contains(x, y);
}
// Test routine.
public static void main(String[] args) {
// Create a button with the label "Hymanpot".
JButton button = new RoundButton("Hymanpot");
button.setBackground(Color.green);
// Create a frame in which to show the button.
JFrame frame = new JFrame();
frame.getContentPane().setBackground(Color.yellow);
frame.getContentPane().add(button);
frame.getContentPane().setLayout(new FlowLayout());
frame.setSize(150, 150);
frame.setVisible(true);
}
}
