java图形界面编程之模拟血压计

import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
import javax.swing.UIManager;

/**
 * 模拟血压计类,高压、低压
 *
 * @author 樊俊彬
 * @Time 2013-12-10
 */
public class Blood extends JFrame {

 private static final long serialVersiOnUID= 1L;
 private Image iBuffer;
 private MyCanvas bloodCanvas = new MyCanvas();
 private JTextField highPressText, lowPressText;

 // 画布长宽
 private final int CANVAS_WIDTH = 400;
 private final int CANVAS_HEIGHT = 800;

 // 玻璃外壳长宽与起始坐标
 private final int BLOOD_WIDTH = 30;
 private final int BLOOD_HEIGHT = 650;
 private final int BLOOD_X = CANVAS_WIDTH / 2 - BLOOD_WIDTH / 2;
 private final int BLOOD_Y = 50;

 // 框架大小与起始坐标
 private final int FRAME_WIDTH = 120;
 private final int FRAME_HEIGHT = 720;
 private final int FRAME_X = CANVAS_WIDTH / 2 - FRAME_WIDTH / 2;
 private final int FRAME_Y = BLOOD_Y - 20;

 // 0刻度线的横纵坐标与长度
 private final int ZORELINE_Y = BLOOD_Y + BLOOD_HEIGHT - 10;
 private final int ZORELINE_X = CANVAS_WIDTH / 2 + BLOOD_WIDTH / 2;
 private final int LINE_LENGTH = 8;

 // 输入的高压、低压
 private int highPressInput, lowPressInput;

 // 高、低压水银柱的动态高度
 int highPressHeight = 0;
 int lowPressHeight = 0;
 int startLow = BLOOD_Y;

 // 高、低水银计时器
 Timer highPressTimer, lowPressTimer;

 public Blood() {

  super("自定义血压计模型-FreeDoman");
  this.setDefaultCloseOperation(EXIT_ON_CLOSE);
  this.setBounds(300, 50, CANVAS_WIDTH, CANVAS_HEIGHT + 20);

  // 添加控制到框架北部区
  JPanel topPanel = new JPanel();
  this.add(topPanel, BorderLayout.NORTH);
  highPressText = new JTextField(5);
  lowPressText = new JTextField(5);

  JButton pressButton = new JButton("显示");
  pressButton.addActionListener(new ActionListener() {

   @Override
   public void actionPerformed(ActionEvent arg0) {
    highPressInput = Integer.parseInt(highPressText.getText());
    lowPressInput = Integer.parseInt(lowPressText.getText());

    ActionListener highPressTaskPerformer = new ActionListener() {
     public void actionPerformed(ActionEvent evt) {
      // 高度增加 1像素/0.01s,只到满足输入的要求,停止计时
      highPressHeight += 1;
      bloodCanvas.repaint();
      if (highPressHeight == highPressInput * 2) {
       highPressTimer.stop();

       // 低压水银柱计时器嵌套于高压计时器内部,有先后顺序(高压先走,后低压)
       startLow = ZORELINE_Y - highPressHeight;
       ActionListener lowPressTaskPerformer = new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
         lowPressHeight += 1;
         bloodCanvas.repaint();
         if (lowPressHeight == ZORELINE_Y
           - lowPressInput * 2 - startLow)
          lowPressTimer.stop();
        }
       };
       lowPressTimer = new Timer(10, lowPressTaskPerformer);
       lowPressTimer.start();
      }
     }
    };
    // 定义每0.01秒执行一次的事件监听器
    highPressTimer = new Timer(10, highPressTaskPerformer);
    highPressTimer.start();
   }
  });

  topPanel.add(new JLabel("高压值", JLabel.CENTER));
  topPanel.add(highPressText);
  topPanel.add(new JLabel("低压值", JLabel.CENTER));
  topPanel.add(lowPressText);
  // topPanel.add(new JLabel("心率", JLabel.CENTER));
  topPanel.add(pressButton);
  // 添加画布到中央区
  this.add(bloodCanvas, BorderLayout.CENTER);
  this.setResizable(false);
  this.setVisible(true);
 }

 /**
  * 画布重绘血压计
  */
 class MyCanvas extends Canvas {
  public void paint(Graphics g) {

   // 画边框
   g.setColor(Color.BLACK);
   g.draw3DRect(FRAME_X, FRAME_Y, FRAME_WIDTH, FRAME_HEIGHT, true);

   // 画玻璃外壳
   g.setColor(Color.ORANGE);
   g.fill3DRect(BLOOD_X, BLOOD_Y, BLOOD_WIDTH, BLOOD_HEIGHT, true);

   // 高压水银柱
   g.setColor(Color.RED);
   g.fill3DRect(BLOOD_X, ZORELINE_Y - highPressHeight, BLOOD_WIDTH,
     highPressHeight, true);

   // 低压高压水银柱
   g.setColor(Color.ORANGE);
   g.fill3DRect(BLOOD_X, startLow, BLOOD_WIDTH, lowPressHeight, true);

   // 画底部水银圆球
   g.setColor(Color.RED);
   g.fillOval(CANVAS_WIDTH / 2 - 30, ZORELINE_Y - 5, 60, 60);

   // 右侧0刻度线起始刻度与坐标(刻度线纵坐标以line_y渐变)
   int rightStartDegree = 0;

   int line_y = ZORELINE_Y;
   for (; line_y > BLOOD_Y; line_y -= 2) {

    // 2个像素点为一个最小分度 1度
    g.setColor(Color.BLACK);
    g.drawLine(ZORELINE_X, line_y, ZORELINE_X + LINE_LENGTH, line_y);

    // 每隔10最小分度个画10度刻度线
    if (line_y % 20 == 10) {
     g.setColor(Color.BLUE);
     g.drawLine(ZORELINE_X, line_y,
       ZORELINE_X + LINE_LENGTH * 2, line_y);
     g.drawString(rightStartDegree + "", ZORELINE_X
       + LINE_LENGTH * 3, line_y + 4);
     rightStartDegree += 10;
    }
   }

   // 左侧0刻度线起始刻度与坐标(刻度线纵坐标以line_y渐变)
   int leftStartDegree = 0;
   int leftLine_y = ZORELINE_Y;
   for (; leftLine_y > BLOOD_Y; leftLine_y -= 6) {

    // 6个像素点为一个最小分度 1度
    g.setColor(Color.BLACK);
    g.drawLine(BLOOD_X, leftLine_y, BLOOD_X - LINE_LENGTH,
      leftLine_y);

    // 每隔10最小分度个画10度刻度线
    if (leftLine_y % 20 == 10) {
     g.setColor(Color.BLUE);
     g.drawLine(BLOOD_X, leftLine_y, BLOOD_X - LINE_LENGTH * 2,
       leftLine_y);
     g.drawString(leftStartDegree + "", BLOOD_X - LINE_LENGTH
       * 4, leftLine_y + 4);
     leftStartDegree += 10;
    }
   }
  }

  /**
   * 双缓冲技术：复杂的计算速度慢于屏幕显示，用缓冲解决屏幕闪烁问题
   */

  @Override
  public void update(Graphics g) {
   if (iBuffer == null) {
    iBuffer = createImage(this.getSize().width,
      this.getSize().height);

   }
   Graphics gBuffer = iBuffer.getGraphics();
   gBuffer.setColor(getBackground());
   gBuffer.fillRect(0, 0, this.getSize().width, this.getSize().height);
   paint(gBuffer);
   gBuffer.dispose();
   g.drawImage(iBuffer, 0, 0, this);
  }
 }

 public static void main(String[] args) {

  // 设置界面的外观，为系统外观
  try {
   UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
  } catch (Exception e) {
   e.printStackTrace();
  }

  new Blood();
 }
}