我刚遇到了同样的问题,@Lalchand 的答案给了我灵感。我创建了一个自定义类来实现圆角边框,它实际上是 LineBorder
类的修改版本。它绘制了两个矩形:inner
和 outer
。对于我的情况,如果边框的颜色与背景相同就可以了,但如果你需要其他颜色,你应该调整 inner
和 outer
的尺寸。而且,作为创意自由,我使用了亚像素渲染来使边框更加平滑。
import javax.swing.border.LineBorder;
import java.awt.*;
import java.awt.geom.Path2D;
import java.awt.geom.RoundRectangle2D;
class RoundedBorder extends LineBorder {
private int radius;
RoundedBorder(Color c, int thickness, int radius) {
super(c, thickness, true);
this.radius = radius;
}
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
if ((this.thickness > 0) && (g instanceof Graphics2D)) {
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
Color oldColor = g2d.getColor();
g2d.setColor(this.lineColor);
Shape outer;
Shape inner;
int offs = this.thickness;
int size = offs + offs;
outer = new RoundRectangle2D.Float(x, y, width, height, 0, 0);
inner = new RoundRectangle2D.Float(x + offs, y + offs, width - size, height - size, radius, radius);
Path2D path = new Path2D.Float(Path2D.WIND_EVEN_ODD);
path.append(outer, false);
path.append(inner, false);
g2d.fill(path);
g2d.setColor(oldColor);
}
}
}