用JAVA制作一个画图程序
- 在日常生活中画图软件给我们带来了许多便利，往大了说可以用它来制作图标，往小了说也可以当做一个涂鸦板消磨时间。
比如：制作个图标
用来画画：
这个画图程序界面如上，这个程序的功能如下：
1.可更改的画笔粗细（1.细线 2.较粗线 3.粗线），效果如下：
- 更改背景颜色：
3.更改画笔颜色：
4.清除功能：
5.橡皮涂擦功能：
6.添加图片水印：
我们该如何制作这个软件呢？代码如下：
- 更改背景颜色：
1. 首先，创建一个DrawPirtureFrame类：
package com.tcz.draw;
import javax.swing.ButtonGroup;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JToggleButton;
import javax.swing.JToolBar;
import java.awt.color.*;
import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.event.MouseMotionListener;
public class DrawPictureFrame extends JFrame {
BufferedImage image = new BufferedImage(1160, 830, BufferedImage.TYPE_INT_BGR);
Graphics gs = image.getGraphics();
Graphics2D g = (Graphics2D) gs;
DrawPictureCanvas canvas = new DrawPictureCanvas();
Color forecColor = Color.black;
Color backgroundColor = Color.white;
int x = -1;
int y = -1;
boolean rubber = false;
/*
* 创建按钮，菜单组件
*/
private JToolBar toolBar;
private JButton eraserButton;
private JToggleButton strokeButton1;
private JToggleButton strokeButton2;
private JToggleButton strokeButton3;
private JButton backgroundButton;
private JButton foreroundButton;
private JButton clearButton;
private JButton savebButton;
private JButton shapeButton;
private JMenuItem strokeMenuItem1;
private JMenuItem strokeMenuItem2;
private JMenuItem strokeMenuItem3;
private JMenuItem clearMenuItem;
private JMenuItem foregroundMenuItem;
private JMenuItem backgroundItem;
private JMenuItem eraserMenuItem;
private JMenuItem exitMenuItem;
private JMenuItem saveMenuItem;
private String shuiyin = "";
private JMenuItem shuiyinMenuItem;
public DrawPictureFrame() {
setResizable(false);//设为不可更改大小
setTitle("画图程序(水印内容：[" + shuiyin + "])");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setBounds(500, 100, 1160, 920);
init();
addListener();
}
private void init() {
g.setColor(backgroundColor);
g.fillRect(0, 0, 1160, 830);
g.setColor(forecColor);
canvas.setImage(image);
getContentPane().add(canvas);
toolBar = new JToolBar();
getContentPane().add(toolBar, BorderLayout.NORTH);//将工具栏放在窗体上边
/*
* 设置各组件位置
*/
savebButton = new JButton("保存");
savebButton.setToolTipText("保存");
toolBar.add(savebButton);
toolBar.addSeparator();
strokeButton1 = new JToggleButton("细线");
strokeButton1.setSelected(true);
toolBar.add(strokeButton1);
strokeButton2 = new JToggleButton("较粗线");
toolBar.add(strokeButton2);
strokeButton3 = new JToggleButton("粗线");
ButtonGroup strokeGroup = new ButtonGroup();
strokeGroup.add(strokeButton1);
strokeGroup.add(strokeButton2);
strokeGroup.add(strokeButton3);
toolBar.add(strokeButton3);
toolBar.addSeparator();
backgroundButton = new JButton("背景颜色");
toolBar.add(backgroundButton);
foreroundButton = new JButton("画笔颜色");
toolBar.add(foreroundButton);
toolBar.addSeparator();
clearButton = new JButton("清除");
toolBar.add(clearButton);
eraserButton = new JButton("橡皮");
toolBar.add(eraserButton);
JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);
JMenu systemMenu = new JMenu("系统");
menuBar.add(systemMenu);
shuiyinMenuItem = new JMenuItem("水印");
systemMenu.add(shuiyinMenuItem);
saveMenuItem = new JMenuItem("保存");
systemMenu.add(saveMenuItem);
systemMenu.addSeparator();
exitMenuItem = new JMenuItem("退出");
systemMenu.add(exitMenuItem);
JMenu strokeMenu = new JMenu("线型");
menuBar.add(strokeMenu);
strokeMenuItem1 = new JMenuItem("细线");
strokeMenu.add(strokeMenuItem1);
strokeMenuItem2 = new JMenuItem("较粗线");
strokeMenu.add(strokeMenuItem2);
strokeMenuItem3 = new JMenuItem("粗线");
strokeMenu.add(strokeMenuItem3);
JMenu colorMenu = new JMenu("颜色");
menuBar.add(colorMenu);
foregroundMenuItem = new JMenuItem("前景颜色");
colorMenu.add(foregroundMenuItem);
backgroundItem = new JMenuItem("背景颜色");
colorMenu.add(backgroundItem);
JMenu editMenu = new JMenu("编辑");
menuBar.add(editMenu);
clearMenuItem = new JMenuItem("清除");
editMenu.add(clearMenuItem);
eraserMenuItem = new JMenuItem("橡皮");
editMenu.add(eraserMenuItem);
}
private void addListener() {
canvas.addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(final MouseEvent e) {
if (x > 0 && y > 0) {
if (rubber) {
g.setColor(backgroundColor);
g.fillRect(x, y, 20, 20);
} else {
g.drawLine(x, y, e.getX(), e.getY());
}
}
x = e.getX();
y = e.getY();
canvas.repaint();
}
@Override
public void mouseMoved(MouseEvent e) {
if (rubber) {
Toolkit kit = Toolkit.getDefaultToolkit();
setCursor(DEFAULT_CURSOR);//设置鼠标显示样式
} else {
setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
}
}
});
canvas.addMouseListener(new MouseAdapter() {
public void mouseReleased(final MouseEvent arg0) {
x = -1;
y = -1;
}
});
strokeButton1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
BasicStroke bs = new BasicStroke(1, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
g.setStroke(bs);
}
});
strokeButton2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
BasicStroke bs = new BasicStroke(2, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
g.setStroke(bs);
}
});
strokeButton3.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
BasicStroke bs = new BasicStroke(4, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
g.setStroke(bs);
}
});
backgroundButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color bgColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
if (bgColor != null) {
backgroundColor = bgColor;
}
backgroundButton.setBackground(backgroundColor);
g.setColor(backgroundColor);
g.fillRect(0, 0, 1160, 830);
g.setColor(forecColor);
canvas.repaint();
}
});
foreroundButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color fColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
if (fColor != null) {
forecColor = fColor;
}
foreroundButton.setBackground(forecColor);
g.setColor(forecColor);
}
});
clearButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
g.setColor(backgroundColor);
g.fillRect(0, 0, 1160, 830);
g.setColor(forecColor);
canvas.repaint();
}
});
eraserButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (eraserButton.getText().equals("橡皮")) {
rubber = true;
eraserMenuItem.setText("画图");
eraserButton.setText("画图");
} else {
rubber = false;
eraserMenuItem.setText("橡皮");
eraserButton.setText("橡皮");
g.setColor(forecColor);
}
}
});
savebButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
addWatermark();
}
});
// 细线菜单项
strokeMenuItem1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
BasicStroke bs = new BasicStroke(1, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
g.setStroke(bs);
}
});
// 较粗线菜单项
strokeMenuItem2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
BasicStroke bs = new BasicStroke(2, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
g.setStroke(bs);
}
});
// 粗线菜单项
strokeMenuItem3.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
BasicStroke bs = new BasicStroke(4, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
g.setStroke(bs);
}
});
foregroundMenuItem.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color fColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
if (fColor != null) {
forecColor = fColor;
}
foreroundButton.setBackground(forecColor);
g.setColor(forecColor);
}
});
backgroundItem.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color bgColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
if (bgColor != null) {
backgroundColor = bgColor;
}
backgroundButton.setBackground(backgroundColor);
g.setColor(backgroundColor);
g.fillRect(0, 0, 1160, 830);
g.setColor(forecColor);
canvas.repaint();
}
});
clearMenuItem.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
g.setColor(backgroundColor);
g.fillRect(0, 0, 1160, 830);
g.setColor(forecColor);
canvas.repaint();
}
});
eraserMenuItem.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (eraserButton.getText().equals("橡皮")) {
rubber = true;
eraserButton.setText("画图");
eraserMenuItem.setText("画图");
} else {
rubber = false;
eraserButton.setText("橡皮");
eraserMenuItem.setText("橡皮");
g.setColor(forecColor);
}
}
});
exitMenuItem.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
shuiyinMenuItem.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
shuiyin = JOptionPane.showInputDialog(DrawPictureFrame.this, "你想添加什么水印？");
if (null == shuiyin) {
shuiyin = "";
} else {
setTitle("画图程序(水印内容：[" + shuiyin + "])");
}
}
});
toolBar.addMouseMotionListener(new MouseMotionAdapter() {//工具栏添加鼠标事件监听
@Override
public void mouseMoved(MouseEvent e) {
setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));//设置鼠标的形状为默认光标
}
});
}
private void addWatermark() {
if (!"".equals(shuiyin.trim())) {// 如果水印字段不是空字符串
g.rotate(Math.toRadians(-30));
Font font = new Font("楷体", Font.BOLD, 72);
g.setFont(font);
g.setColor(Color.GRAY);
AlphaComposite alpha = AlphaComposite.SrcOver.derive(0.4f);// 设置透明效果
g.setComposite(alpha);
g.drawString(shuiyin, 350, 900);
canvas.repaint();
g.rotate(Math.toRadians(30));// 将旋转的图片再转回来
alpha = AlphaComposite.SrcOver.derive(1f);// 不透明效果
g.setComposite(alpha);// 使用不透明效果
g.setColor(forecColor);// 画笔恢复之前的颜色
}
}
public static void main(String[] args) {
DrawPictureFrame frame = new DrawPictureFrame();
frame.setVisible(true);
}
}
2.创建第二个类：
package com.tcz.draw;
import java.awt.Canvas;
import java.awt.Graphics;
import java.awt.Image;
public class DrawPictureCanvas extends Canvas{
private Image image=null;
public void setImage(Image image) {
this.image=image;
}
@Override
public void paint(Graphics g) {
g.drawImage(image, 0, 0, null);
}
public void update(Graphics g) {
paint(g);
}
心动不如行动，编写一个画图程序，体验绘画之美！更多有趣的功能等你来体验哦！
