第十九章Java绘图总结

                                一、Java绘图类

 

 二、绘制图形

绘制奥运五环图案

package nineteentn;
import java.awt.*;
import javax.swing.*;
 
public class DrawCircle extends JFrame {
	private final int OVAL_WIDTH = 80; // 圆形的宽
	private final int OVAL_HEIGHT = 80; // 圆形的高
 
	public DrawCircle() {
		initialize(); // 调用初始化方法
	}
 
	private void initialize() {// 初始化方法
		setSize(300, 200); // 设置窗体大小
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		setContentPane(new DrawPanel()); // 设置窗体面板为绘图面板对象
		setTitle("绘图实例1"); // 设置窗体标题
	}
 
	class DrawPanel extends JPanel {// 创建绘图面板
		public void paint(Graphics g) {// 重写绘制方法
			g.drawOval(10, 10, OVAL_WIDTH, OVAL_HEIGHT); // 绘制第1个圆形
			g.drawOval(80, 10, OVAL_WIDTH, OVAL_HEIGHT); // 绘制第2个圆形
			g.drawOval(150, 10, OVAL_WIDTH, OVAL_HEIGHT); // 绘制第3个圆形
			g.drawOval(50, 70, OVAL_WIDTH, OVAL_HEIGHT); // 绘制第4个圆形
			g.drawOval(120, 70, OVAL_WIDTH, OVAL_HEIGHT); // 绘制第5个圆形
		}
	}
 
	public static void main(String[] args) {
		new DrawCircle().setVisible(true);
	}

绘制空心和实心

package nineteentn;

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;

public class DrawFrame extends JFrame {
	public DrawFrame() {
		setTitle("绘图实例2"); // 设置窗体标题
		setSize(300, 200); // 设置窗体大小
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		add(new CanvasPanel()); // 设置窗体面板为绘图面板对象

	}

	class CanvasPanel extends JPanel {// 绘图变慢
		public void paint(Graphics g) {
			Graphics2D g2 = (Graphics2D) g;
			Shape[] shapes = new Shape[4]; // 声明图形数组
			shapes[0] = new Ellipse2D.Double(5, 5, 100, 100); // 创建圆形对象
			shapes[1] = new Rectangle2D.Double(110, 5, 100, 100); // 创建矩形对象

			shapes[2] = new Rectangle2D.Double(15, 15, 80, 80); // 创建矩形对象
			shapes[3] = new Ellipse2D.Double(120, 15, 80, 80); // 创建圆形对象
			for (Shape shape : shapes) { // 遍历图形数组
				Rectangle2D bounds = shape.getBounds2D();
				if (bounds.getWidth() == 80)
					g2.fill(shape); // 填充图形
				else
					g2.draw(shape); // 绘制图形
			}
		}
	}

	public static void main(String[] args) {
		new DrawFrame().setVisible(true);
	}
}

改颜色

三、绘制颜色与画笔属性

1.设置颜色

创建Color对象的构造方法有如下俩种：

Color col=new Color(int r, int g,int b)

Color col=new Color(int rgb)

 设置当前颜色：

setColor(Color color)

 2.设置画笔

设置画笔属性：

setStroke(Stroke stroke)

四、绘制文本

1.设置字体

构造方法指定字体名称：

Font(String name,int style,int size) 

2.显示文字 

语法格式：

drawString(String str,int x,int y)

drawString(String str,float x,float y)

import java.awt.*;
import java.awt.geom.Rectangle2D;
import java.util.Date;
import javax.swing.*;

public class DrawString extends JFrame {

	public DrawString() {
		setSize(230, 140); // 设置窗体大小
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		add(new CanvasPanel()); // 设置窗体面板为绘图面板对象
		setTitle("绘图文本"); // 设置窗体标题
	}

	class CanvasPanel extends JPanel {
		public void paint(Graphics g) {
			Graphics2D g2 = (Graphics2D) g;
			Rectangle2D rect = new Rectangle2D.Double(10, 10, 200, 80);
			Font font = new Font("宋体", Font.BOLD, 16);
			Date date = new Date();
			g2.setColor(Color.CYAN); // 设置当前绘图颜色
			g2.fill(rect); // 填充矩形
			g2.setColor(Color.BLUE); // 设置当前绘图颜色
			g2.setFont(font); // 设置字体
			g2.drawString("现在时间是", 20, 30); // 绘制文本
			g2.drawString(String.format("%tr", date), 50, 60); // 绘制时间文本
		}
	}

	public static void main(String[] args) {
		new DrawString().setVisible(true);
	}
}

 五、显示图片

package nineteentn;

import java.awt.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;

public class DrawImage extends JFrame {
	Image img;// 展示的图片

	public DrawImage() {
		try {
			img = ImageIO.read(new File("src/海豚.png"));// 读取图片文件
		} catch (IOException e) {
			e.printStackTrace();
		}
		setSize(440, 300); // 设置窗体大小
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		add(new CanvasPanel()); // 设置窗体面板为绘图面板对象
		setTitle("绘制图片"); // 设置窗体标题
	}

	class CanvasPanel extends JPanel {
		public void paint(Graphics g) {
			Graphics2D g2 = (Graphics2D) g;
			g2.drawImage(img, 0, 0, this); // 显示图片
		}
	}

	public static void main(String[] args) {
		new DrawImage().setVisible(true);
	}
}

六、图像处理

package nineteentn;
import java.awt.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.event.*;

public class ImageZoom extends JFrame {
	Image img;
	private int imgWidth, imgHeight;
	private JSlider jSlider;

	public ImageZoom() {
		try {
			img = ImageIO.read(new File("src/海豚.png"));// 读取图片文件
		} catch (IOException e) {
			e.printStackTrace();
		}

		CanvasPanel canvas = new CanvasPanel();
		jSlider = new JSlider();
		jSlider.setMaximum(1000);
		jSlider.setValue(100);
		jSlider.setMinimum(1);
		jSlider.addChangeListener(new ChangeListener() {
			public void stateChanged(ChangeEvent e) {
				canvas.repaint();
			}
		});

		JPanel center = new JPanel();
		center.setLayout(new BorderLayout());
		center.add(jSlider, BorderLayout.SOUTH);
		center.add(canvas, BorderLayout.CENTER);
		setContentPane(center);
		setBounds(100, 100, 800, 600); // 设置窗体大小和位置
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		setTitle("绘制图片");
	}

	class CanvasPanel extends JPanel {
		public void paint(Graphics g) {
			int newW = 0, newH = 0;
			imgWidth = img.getWidth(this); // 获取图片宽度
			imgHeight = img.getHeight(this); // 获取图片高度
			float value = jSlider.getValue();// 滑块组件的取值
			newW = (int) (imgWidth * value / 100);// 计算图片放大后的宽度
			newH = (int) (imgHeight * value / 100);// 计算图片放大后的高度
			g.drawImage(img, 0, 0, newW, newH, this);// 绘制指定大小的图片
		}
	}

	public static void main(String[] args) {
		new ImageZoom().setVisible(true);
	}
}

2.图像翻转 

package nineteentn;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.imageio.ImageIO;

public class PartImage extends JFrame {
	private Image img;
	private int dx1, dy1, dx2, dy2;
	private int sx1, sy1, sx2, sy2;
	private int width = 300, height = 200;// 图片宽高
	private JButton vBtn = null;// 垂直翻转按钮
	private JButton hBtn = null;// 水平翻转按钮
	private CanvasPanel canvasPanel = null;

	public PartImage() {

		try {
			img = ImageIO.read(new File("src/海豚.png"));// 读取图片文件
		} catch (IOException e) {
			e.printStackTrace();
		}
		dx2 = sx2 = width; // 初始化图像大小
		dy2 = sy2 = height;

		vBtn = new JButton("垂直翻转");
		hBtn = new JButton("水平翻转");

		JPanel bottom = new JPanel();
		bottom.add(hBtn);
		bottom.add(vBtn);

		Container c = getContentPane();
		c.add(bottom, BorderLayout.SOUTH);
		canvasPanel = new CanvasPanel();
		c.add(canvasPanel, BorderLayout.CENTER);

		addListener();

		setBounds(100, 100, 300, 260); // 设置窗体大小和位置
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		setTitle("图片翻转"); // 设置窗体标题
	}

	private void addListener() {
		vBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				sy1 = Math.abs(sy1 - height);// 纵坐标互换
				sy2 = Math.abs(sy2 - height);
				canvasPanel.repaint();
			}
		});
		hBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				sx1 = Math.abs(sx1 - width);// 横坐标互换
				sx2 = Math.abs(sx2 - width);
				canvasPanel.repaint();
			}
		});
	}

	class CanvasPanel extends JPanel {
		public void paint(Graphics g) {
			g.drawImage(img, dx1, dy1, dx2, dy2, sx1, sy1, sx2, sy2, this);// 绘制指定大小的图片
		}
	}

	public static void main(String[] args) {
		new PartImage().setVisible(true);
	}
}

 

3.图像旋转 

package nineteentn;

import java.awt.*;
import java.io.*;
import javax.swing.*;
import javax.imageio.ImageIO;

public class RotateImage extends JFrame {
	private Image img;

	public RotateImage() {
		try {
			img = ImageIO.read(new File("src/海豚.png"));// 读取图片文件
		} catch (IOException e) {
			e.printStackTrace();
		}
		setBounds(100, 100, 400, 350); // 设置窗体大小和位置
		add(new CanvasPanel());
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		setTitle("图片旋转"); // 设置窗体标题
	}

	class CanvasPanel extends JPanel { // 画板
		public void paint(Graphics g) {
			Graphics2D g2 = (Graphics2D) g;
			g2.rotate(Math.toRadians(5));// 旋转5度
			g2.drawImage(img, 70, 10, 300, 200, this);
			g2.rotate(Math.toRadians(5));
			g2.drawImage(img, 70, 10, 300, 200, this);
			g2.rotate(Math.toRadians(5));
			g2.drawImage(img, 70, 10, 300, 200, this);
		}
	}

	public static void main(String[] args) { // 主方法
		new RotateImage().setVisible(true);
	}
}

4.图像倾斜

package nineteentn;
import java.awt.*;
import java.io.*;
import javax.swing.*;
import javax.imageio.ImageIO;

public class TiltImage extends JFrame {
	private Image img;

	public TiltImage() {
		try {
			img = ImageIO.read(new File("src/cow.jpg"));// 读取图片文件
		} catch (IOException e) {
			e.printStackTrace();
		}
		setBounds(100, 100, 400, 300); // 设置窗体大小和位置
		add(new CanvasPanel());
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭模式
		setTitle("图片倾斜"); // 设置窗体标题
	}

	class CanvasPanel extends JPanel {
		public void paint(Graphics g) {
			Graphics2D g2 = (Graphics2D) g;
			g2.shear(0.3, 0);// 倾斜30%
			g2.drawImage(img, 0, 0, 300, 200, this);
		}
	}

	public static void main(String[] args) {
		new TiltImage().setVisible(true);
	}
}