我有一个自定义的滚动条UI,我会绘制滚动条的拇指和轨道。但是当滚动时,它会保留一些不需要的线条,如下图所示:
绘制代码如下:
![enter image description here](https://istack.dev59.com/v40bz.webp)
protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
Graphics2D g2d = (Graphics2D) g;
GradientPaint gradient = new GradientPaint(new Point(thumbBounds.x, thumbBounds.y), gray, new Point(thumbBounds.x + width, thumbBounds.y), white);
g.setColor(white);
g.fillRoundRect(thumbBounds.x + 1, thumbBounds.y + 1, thumbBounds.width - 3, thumbBounds.height - 1, 2, 2);
g2d.setPaint(gradient);
g2d.fillRoundRect(thumbBounds.x + 2, thumbBounds.y + 2, thumbBounds.width - 4, thumbBounds.height - 3, 3, 3);
//Draw middle lines:
if ((getMinimumThumbSize().height + 10) < thumbBounds.height) {
g.setColor(new Color(167, 167, 167));
int w = ((thumbBounds.width > 16) ? 8 : (int) ((thumbBounds.width / 2.0) + 0.5));
int x = (thumbBounds.width > 0) ? (thumbBounds.x + ((thumbBounds.width - w) / 2) - 1) : thumbBounds.x;
g.drawLine(x, (thumbBounds.y + (thumbBounds.height / 2) - 3), (x + w), (thumbBounds.y + (thumbBounds.height / 2) - 3));
g.drawLine(x, (thumbBounds.y + (thumbBounds.height / 2) - 1), (x + w), (thumbBounds.y + (thumbBounds.height / 2) - 1));
g.drawLine(x, (thumbBounds.y + (thumbBounds.height / 2) + 1), (x + w), (thumbBounds.y + (thumbBounds.height / 2) + 1));
}
g.setColor(color_1);
g.drawRoundRect(thumbBounds.x, thumbBounds.y, thumbBounds.width - 2, thumbBounds.height, 2, 2);
}
g.drawRoundRect(...,thumbBounds.height-1,2,2)
而不是g.drawRoundRect(...,thumbBounds.height,2,2)
。 - aterai