201771010141 周强 面向对象程序设计（Java）第12周作业

实验十二  图形程序设计

实验时间 2018-11-14

1、实验目的与要求

(1) 掌握Java GUI中框架创建及属性设置中常用类的API；

(2) 掌握Java GUI中2D图形绘制常用类的API；

(3) 了解Java GUI中2D图形中字体与颜色的设置方法；

(4) 了解Java GUI中2D图像的载入方法。

2、实验内容和步骤

实验1： 导入第10章示例程序，测试程序并进行代码注释。

测试程序1：

l 运行下列程序，观察程序运行结果。

import javax.swing.*;

public class SimpleFrameTest

{

public static void main(String[] args)

{

JFrame  frame = new JFrame();

frame.setBounds(0, 0,300, 200);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setVisible(true);

}

}

l 在elipse IDE中调试运行教材407页程序10-1，结合程序运行结果理解程序；与上面程序对比，思考异同；

import java.awt.*;
import javax.swing.*;
 
/**
 * @version 1.33 2015-05-12
 * @author Cay Horstmann
 */
public class SimpleFrameTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() ->
         {
            SimpleFrame frame = new SimpleFrame();
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
         });
   }
}
 
class SimpleFrame extends JFrame
{
   private static final int DEFAULT_WIDTH = ;
   private static final int DEFAULT_HEIGHT = ;
 
   public SimpleFrame()
   {
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
   }
}

l 掌握空框架创建方法；

l 了解主线程与事件分派线程概念；

l 掌握GUI顶层窗口创建技术。

测试程序2：

l 在elipse IDE中调试运行教材412页程序10-2，结合程序运行结果理解程序；

l 掌握确定框架常用属性的设置方法。

package sizedFrame;

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

/**
* @version 1.34 2015-06-16
* @author Cay Horstmann
*/
public class SizedFrameTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(() ->
{
JFrame frame = new SizedFrame();
frame.setTitle("SizedFrame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}

class SizedFrame extends JFrame
{
public SizedFrame()
{
// get screen dimensions

Toolkit kit = Toolkit.getDefaultToolkit();
Dimension screenSize = kit.getScreenSize();
int screenHeight = screenSize.height;
int screenWidth = screenSize.width;

// set frame width, height and let platform pick screen location

setSize(screenWidth / 2, screenHeight / 2);
setLocationByPlatform(true);

// set frame icon

Image img = new ImageIcon("icon.gif").getImage();
setIconImage(img);
}
}

测试程序3：

l 在elipse IDE中调试运行教材418页程序10-3，结合运行结果理解程序；

l 掌握在框架中添加组件；

l 掌握自定义组件的用法。

package notHelloWorld;

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

/**
* @version 1.33 2015-05-12
* @author Cay Horstmann
*/
public class NotHelloWorld
{
public static void main(String[] args)
{
EventQueue.invokeLater(() ->
{
JFrame frame = new NotHelloWorldFrame();
frame.setTitle("NotHelloWorld");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}

/**
* A frame that contains a message panel
*/
class NotHelloWorldFrame extends JFrame
{
public NotHelloWorldFrame()
{
add(new NotHelloWorldComponent());
pack();
}
}

/**
* A component that displays a message.
*/
class NotHelloWorldComponent extends JComponent
{
public static final int MESSAGE_X = 75;
public static final int MESSAGE_Y = 100;

private static final int DEFAULT_WIDTH = 300;
private static final int DEFAULT_HEIGHT = 200;

public void paintComponent(Graphics g)
{
g.drawString("Not a Hello, World program", MESSAGE_X, MESSAGE_Y);
}

public Dimension getPreferredSize() { return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT); }
}

测试程序4：

l 在elipse IDE中调试运行教材424 -425页程序10-4，结合程序运行结果理解程序；

l 掌握2D图形的绘制方法。

package draw;

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

/**
* @version 1.33 2007-05-12
* @author Cay Horstmann
*/
public class DrawTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(() ->
{
JFrame frame = new DrawFrame();
frame.setTitle("DrawTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}

/**
* A frame that contains a panel with drawings
*/
class DrawFrame extends JFrame
{
public DrawFrame()
{
add(new DrawComponent());
pack();
}
}

/**
* A component that displays rectangles and ellipses.
*/
class DrawComponent extends JComponent
{
private static final int DEFAULT_WIDTH = 400;
private static final int DEFAULT_HEIGHT = 400;

public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;

// draw a rectangle

double leftX = 100;
double topY = 100;
double width = 200;
double height = 150;

Rectangle2D rect = new Rectangle2D.Double(leftX, topY, width, height);
g2.draw(rect);

// draw the enclosed ellipse

Ellipse2D ellipse = new Ellipse2D.Double();
ellipse.setFrame(rect);
g2.draw(ellipse);

// draw a diagonal line

g2.draw(new Line2D.Double(leftX, topY, leftX + width, topY + height));

// draw a circle with the same center

double centerX = rect.getCenterX();
double centerY = rect.getCenterY();
double radius = 150;

Ellipse2D circle = new Ellipse2D.Double();
circle.setFrameFromCenter(centerX, centerY, centerX + radius, centerY + radius);
g2.draw(circle);
}

public Dimension getPreferredSize() { return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT); }
}

测试程序5：

l 在elipse IDE中调试运行教材432页-433程序10-5，结合程序运行结果理解程序；

l 了解2D图形中字体的设置的方法；

package font;

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

/**
* @version 1.34 2015-05-12
* @author Cay Horstmann
*/
public class FontTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(() ->
{
JFrame frame = new FontFrame();
frame.setTitle("FontTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}

/**
* A frame with a text message component
*/
class FontFrame extends JFrame
{
public FontFrame()
{
add(new FontComponent());
pack();
}
}

/**
* A component that shows a centered message in a box.
*/
class FontComponent extends JComponent
{
private static final int DEFAULT_WIDTH = 300;
private static final int DEFAULT_HEIGHT = 200;

public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;

String message = "Happy every day!";

Font f = new Font("Serif", Font.BOLD, 36);
g2.setFont(f);

// measure the size of the message

FontRenderContext context = g2.getFontRenderContext();
Rectangle2D bounds = f.getStringBounds(message, context);

// set (x,y) = top left corner of text

double x = (getWidth() - bounds.getWidth()) / 2;
double y = (getHeight() - bounds.getHeight()) / 2;

// add ascent to y to reach the baseline

double ascent = -bounds.getY();
double baseY = y + ascent;

// draw the message

g2.drawString(message, (int) x, (int) baseY);

g2.setPaint(Color.LIGHT_GRAY);

// draw the baseline

g2.draw(new Line2D.Double(x, baseY, x + bounds.getWidth(), baseY));

// draw the enclosing rectangle

Rectangle2D rect = new Rectangle2D.Double(x, y, bounds.getWidth(), bounds.getHeight());
g2.draw(rect);
}

public Dimension getPreferredSize() { return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT); }
}

测试程序6：

l 在elipse IDE中调试运行教材436页-437程序10-6，结合程序运行结果理解程序；

l 了解2D图形图像的显示方法。

 package image;

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

/**
 * @version 1.34 2015-05-12
 * @author Cay Horstmann
 */
public class ImageTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() ->
         {
            JFrame frame = new ImageFrame();
            frame.setTitle("ImageTest");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
         });
   }
}

/**
 * A frame with an image component
 */
class ImageFrame extends JFrame
{
   public ImageFrame()
   {
      add(new ImageComponent());
      pack();
   }
}

/**
 * A component that displays a tiled image
 */
class ImageComponent extends JComponent
{
   private static final int DEFAULT_WIDTH = 576;
   private static final int DEFAULT_HEIGHT = 1024;

private Image image;

public ImageComponent()
   {
      image = new ImageIcon("QQ图片20181118142923.jpg").getImage();
   }

public void paintComponent(Graphics g)
   {
      if (image == null) return;

int imageWidth = image.getWidth(null);
      int imageHeight = image.getHeight(null);

// draw the image in the upper-left corner

g.drawImage(image, 0, 0, null);
      // tile the image across the component

for (int i = 0; i * imageWidth <= getWidth(); i++)
         for (int j = 0; j * imageHeight <= getHeight(); j++)
            if (i + j > 0) 
               g.copyArea(0, 0, imageWidth, imageHeight, i * imageWidth, j * imageHeight);
   }
   
   public Dimension getPreferredSize() { return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT); }
}

 实验2：课后完成PTA平台题目集：2018秋季西北师范大学面向对象程序设计（Java）练习题集（ch6-ch9)

实验总结： 

             通过这次实验，熟悉了JAVA SWING中的容器、组件、布局以及事件监视器和事件接口的使用。通过该实验掌握了JAVA图形界面程序设计的方法，以及如何设置窗口中的字体，以及窗口的背景，还有字体大小字体颜色有了一定了解。