【Java开源代码栏目提醒】:网学会员--在 Java开源代码编辑为广大网友搜集整理了:TransparencyExample.java绩等信息,祝愿广大网友取得需要的信息,参考学习。
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
public class TransparencyExample extends JPanel {
private static int gap=10, width=40, offset=10,
deltaX=gap+width+offset;
private Rectangle
blueSquare = new Rectangle(gap+offset, gap+offset, width, width),
redSquare = new Rectangle(gap, gap, width, width);
//创建一个指定alpha值的AlphaComposite对象
private AlphaComposite makeComposite(float alpha) {
int type = AlphaComposite.SRC_OVER;
return(AlphaComposite.getInstance(type, alpha));
}
//用指定的alpha值来绘制前景和背景色
private void drawSquares(Graphics2D g2d, float alpha) {
Composite originalComposite = g2d.getComposite();
//用默认透明度绘制背景蓝色
g2d.setPaint(Color.blue);
g2d.fill(blueSquare);
//设置透明度,准备绘制前景红色
g2d.setComposite(makeComposite(alpha));
g2d.setPaint(Color.red);
g2d.fill(redSquare);
//将透明度设置回默认的模式
g2d.setComposite(originalComposite);
}
//分别用不同的透明度来绘制颜色
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
for(int i=0; i<11; i++) {
//alpha值逐步增大,透明度逐步减小
drawSquares(g2d, i*0.1F);
g2d.translate(deltaX, 0);
}
}
}