简单绘画
直线
矩形
圆
根据矩阵画图
package com.zhoudm;
import java.awt.*;
import javax.swing.*;
public class Draw extends JFrame
{
MyPanel mp = null ;
public static void main(String[] args)
{
// TODO Auto-generated method stub
Draw qwe = new Draw();
}
public Draw()
{
mp = new MyPanel();
this.add(mp);
this.setSize(400,300);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
class MyPanel extends JPanel //我自己的面板，用于绘图和实现绘图区域
{
//覆盖JPanel的paint方法
//Graphics是绘图的重要类，可以理解成一支画笔
public void paint(Graphics g)
{
//1.调用父类函数完成初始化
super.paint(g); //这句话不能少
//System.out.println("被调用"); //证明别调用
//画圆
int [][] drawnum={{1,0,1,1},
{0,1,0,1},
{1,0,1,1},
{1,1,0,1}};
for(int i=0;i<drawnum.length;i++){
for(int j=0;j<drawnum[0].length;j++){
if(drawnum[i][j]==1){
g.drawOval(30*i+50,30*j+50,25,25);
g.setColor(Color.BLUE);
}
}
}
// g.drawOval(10, 10, 30, 30);
//画直线
// g.drawLine(20, 30, 20, 80);
//画出矩形边框
// g.drawRect(50, 50, 100, 50);
//画填充矩形
// g.setColor(Color.BLUE); //设置颜色
// g.fillRect(80,60,40,60);
}
}
# Java嵌入图片
```
class MyPanel extends JPanel //我自己的面板，用于绘图和实现绘图区域
{
//覆盖JPanel的paint方法
//Graphics是绘图的重要类，可以理解成一支画笔
public void paint(Graphics g)
{
//放置图片
Image im = Toolkit.getDefaultToolkit().getImage
(Panel.class.getResource("/sysu.jpg"));
g.drawImage(im, 50, 50, 70, 70, this); //this代指JPanel本身，意思是把图片放这上面
}
}
```
# 将矩形图片切成圆形
周边透明！
```
import java.awt.*;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class Main {
public static void main(String[] args) throws IOException {
BufferedImage bi1 = ImageIO.read(new File("G:/code/Java/leetcode/src/mm.jpg"));
// 根据需要是否使用 BufferedImage.TYPE_INT_ARGB
BufferedImage image = new BufferedImage(bi1.getWidth(), bi1.getHeight(),
BufferedImage.TYPE_INT_ARGB);
Ellipse2D.Double shape = new Ellipse2D.Double(0, 0, bi1.getWidth(), bi1
.getHeight());
Graphics2D g2 = image.createGraphics();
image = g2.getDeviceConfiguration().createCompatibleImage(bi1.getWidth(), bi1.getHeight(), Transparency.TRANSLUCENT);
g2 = image.createGraphics();
g2.setComposite(AlphaComposite.Clear);
g2.fill(new Rectangle(image.getWidth(), image.getHeight()));
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC, 1.0f));
g2.setClip(shape);
// 使用 setRenderingHint 设置抗锯齿
g2.drawImage(bi1, 0, 0, null);
g2.dispose();
try {
ImageIO.write(image, "PNG", new File("G:/code/Java/leetcode/src/mm2.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
}
}
# 保存图片
但是保存不了组建图片
Dimension imageSize = qwe.getSize();
BufferedImage image = new BufferedImage(imageSize.width,
imageSize.height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
qwe.paint(g);
g.dispose();
try {
ImageIO.write(image, "png", new File("G:/code/Java/leetcode/src/sysu2.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
