在上篇文章中我们已经对简易画图工具有了一个初步了解下面我们要对一些具体细节进行完善并加上一些新的功能我们直接来看升级点1.界面类加上颜色按钮Color[] colors {Color.BLACK, Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW, Color.PINK, Color.ORANGE, Color.CYAN, Color.MAGENTA}; for(int i 0 ; icolors.length;i){ JButton btn new JButton(C); btn.setBackground(colors[i]); jf.add(btn); btn.addActionListener(dl); }2.监听器类颜色实现color为全局变量并定义为黑色Color color Color.black;JButton btn (JButton)e.getSource(); Color bg btn.getBackground(); color bg; g.setColor(color); //把画笔颜色变为之前的黑色我们来理解一下getSourcegetSource() 找出 “谁被点了”就是这次点击到底是哪个按钮触发的再来注意getSource()返回的是 ObjectJava 不知道它是按钮只知道它是一个东西必须强转成 JButton才能使用按钮独有的方法3.增加Math.min与Math.abs方法并简化图形的处理if (type.equals(矩形)) { // 矩形左上角的坐标 宽度 高度 g.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2 - x1), Math.abs(y2 - y1)); } else if (type.equals(圆形)) { // 外切矩形的左上角坐标 宽度 高度 g.drawOval(x1, y1,Math.abs( x2 - x1),Math.abs( y2 - y1)); } else if (type.equals(实心矩形)) { g.fillRect(x1, y1, Math.abs(x2 - x1),Math.abs( y2 - y1)); } else if (type.equals(实心圆形)) { g.fillOval(x1, y1, Math.abs(x2 - x1), Math.abs(y2 - y1);}这样无论是从上往下还是从下往上都可实现画图4.增加橡皮擦功能if (type.equals(橡皮擦)) { g.setColor(new Color(238, 238, 238)); g.fillOval(x1, y1, 50, 50); g.setColor(color);}5.用渐变来画出球体if (type.equals(球形)) { int x Math.min(x1, x2); int y Math.min(y1, y2); int w Math.abs(x2 - x1); int h Math.abs(y2 - y1); for (int i 0; i w; i) { int cn i; if(cn255){ cn255; } Color c new Color(cn,cn/2,cn);// 0-255 g.setColor(c); g.fillOval(xi/2,yi/2,w-i,h-i}6.用多边形Polygon类来进行顺时针连线Polygon pyg new Polygon(); pyg.addPoint(p1.x, p1.y); pyg.addPoint(p2.x, p2.y); pyg.addPoint(p3.x, p3.y); pyg.addPoint(p4.x, p4.y); Polygon pyg2 new Polygon(); pyg2.addPoint(p1.x, p1.y); pyg2.addPoint(p5.x, p5.y); pyg2.addPoint(p6.x, p6.y); pyg2.addPoint(p2.x, p2.y); Polygon pyg3 new Polygon(); pyg3.addPoint(p2.x, p2.y); pyg3.addPoint(p6.x, p6.y); pyg3.addPoint(p7.x, p7.y); pyg3.addPoint(p3.x, p3.y);7.用渐变色使图形变得立体并调用Polygon类里的方法Color c1 new Color(50,50,50); g.setColor(c1); g.fillPolygon(pyg); Color c2 new Color(100,100,100); g.setColor(c2); g.fillPolygon(pyg2); Color c3 new Color(150,150,150); g.setColor(c3); g.fillPolygon(pyg3);根据6与7我们就可以自己写出一个画3D长方体的Draw3Dbox方法public void Draw3DBox(int x1, int y1, int w ,int h ,int dx, int dy){ Point p1 new Point(x1, y1); Point p2 new Point(x1 w, y1); Point p3 new Point(x1 w, y1 h); Point p4 new Point(x1, y1 h); Point p5 new Point(p1.x dx, p1.y - dy); Point p6 new Point(p5.x w, p5.y); Point p7 new Point(p6.x, p6.y h); Point p8 new Point(p5.x, p5.y h); //多边形类 Polygon pyg new Polygon(); pyg.addPoint(p1.x, p1.y); pyg.addPoint(p2.x, p2.y); pyg.addPoint(p3.x, p3.y); pyg.addPoint(p4.x, p4.y); Polygon pyg2 new Polygon(); pyg2.addPoint(p1.x, p1.y); pyg2.addPoint(p5.x, p5.y); pyg2.addPoint(p6.x, p6.y); pyg2.addPoint(p2.x, p2.y); Polygon pyg3 new Polygon(); pyg3.addPoint(p2.x, p2.y); pyg3.addPoint(p6.x, p6.y); pyg3.addPoint(p7.x, p7.y); pyg3.addPoint(p3.x, p3.y); //加颜色更立体 Color c1 new Color(50,50,50); g.setColor(c1); g.fillPolygon(pyg); Color c2 new Color(100,100,100); g.setColor(c2); g.fillPolygon(pyg2); Color c3 new Color(150,150,150); g.setColor(c3); g.fillPolygon(pyg3); }8.用双层for循环与二维数组实现砖块画首先根据图形具体形状用0和1进行简单模拟int[][] arr { {1,0,0,0,1,1,1,0,0,0,1}, {1,0,0,0,1,1,1,0,0,0,1}, {1,0,0,0,1,1,1,0,0,0,1}, {0,0,0,0,0,0,0,0,0,0,0}, {0,0,1,0,0,0,0,0,1,0,0}, {0,0,1,0,0,0,0,0,1,0,0}, {0,0,0,0,0,0,0,0,0,0,0} };然后双层for循环加上判断并调用draw3Dbox方法int len arr.length; int len2 arr[0].length; for (int i 0;ilen;i){ for (int j 0;jlen2;j){ if(arr[i][j]0) { Draw3DBox(x1 j * (w 1), y1 - i * (h 1), w, h, dx, dy); } } }我们再来看一些细节对x与y加偏移量时要注意w与h后加1或其他数字来控制间距否则会出现重叠而导致看不到我们画了多个长方体只能看到最后的一个大的长方体减低立体效果。那么为什么会出现重叠呢因为我们在画长方体时加了偏移量dxdy它不像矩形一样严丝合缝对接而是会上翘或右翘一部分。若想完全避免看到每一个完整的小长方体可以进行如下代码Draw3DBox(x1 j * (w dx), y1 - i * (h dy), w, h, dx, dy);我们来看一下画图效果最后把所有功能汇编在一起我们来看一下完整代码界面类import javax.swing.*; import java.awt.*; public class DrawUI { DrawListener dl new DrawListener(); public void showUI() { JFrame jf new JFrame(); jf.setTitle(画图板V2.0); jf.setSize(800, 600); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); FlowLayout flow new FlowLayout(); jf.setLayout(flow); String[] btnTexts {直线, 矩形, 圆形, 实心矩形, 实心圆形, 正圆, 等腰三角形, 长方体, 橡皮擦, 球形,砖块画}; for (int i 0; i btnTexts.length; i) { JButton btn new JButton(btnTexts[i]); jf.add(btn); btn.addActionListener(dl); } Color[] colors {Color.BLACK, Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW, Color.PINK, Color.ORANGE, Color.CYAN, Color.MAGENTA}; for (int i 0; i colors.length; i) { JButton btn new JButton(C); btn.setBackground(colors[i]); jf.add(btn); btn.addActionListener(dl); } jf.setVisible(true); jf.addMouseListener(dl); Graphics g jf.getGraphics(); dl.g g; } public static void main(String[] args) { DrawUI ui new DrawUI(); ui.showUI(); } }监听器类import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; public class DrawListener implements MouseListener, ActionListener { int x1, y1, x2, y2; Graphics g; String type ; Color color Color.black; public void Draw3DBox(int x1, int y1, int w ,int h ,int dx, int dy){ Point p1 new Point(x1, y1); Point p2 new Point(x1 w, y1); Point p3 new Point(x1 w, y1 h); Point p4 new Point(x1, y1 h); Point p5 new Point(p1.x dx, p1.y - dy); Point p6 new Point(p5.x w, p5.y); Point p7 new Point(p6.x, p6.y h); Point p8 new Point(p5.x, p5.y h); //多边形类 Polygon pyg new Polygon(); pyg.addPoint(p1.x, p1.y); pyg.addPoint(p2.x, p2.y); pyg.addPoint(p3.x, p3.y); pyg.addPoint(p4.x, p4.y); Polygon pyg2 new Polygon(); pyg2.addPoint(p1.x, p1.y); pyg2.addPoint(p5.x, p5.y); pyg2.addPoint(p6.x, p6.y); pyg2.addPoint(p2.x, p2.y); Polygon pyg3 new Polygon(); pyg3.addPoint(p2.x, p2.y); pyg3.addPoint(p6.x, p6.y); pyg3.addPoint(p7.x, p7.y); pyg3.addPoint(p3.x, p3.y); //加颜色更立体 Color c1 new Color(50,50,50); g.setColor(c1); g.fillPolygon(pyg); Color c2 new Color(100,100,100); g.setColor(c2); g.fillPolygon(pyg2); Color c3 new Color(150,150,150); g.setColor(c3); g.fillPolygon(pyg3); } Override public void actionPerformed(ActionEvent e) { String ac e.getActionCommand(); System.out.println(ac); if (ac.equals(C)) { JButton btn (JButton) e.getSource(); Color bg btn.getBackground(); color bg; g.setColor(color); } else { type ac; } } public void mouseClicked(MouseEvent e) { System.out.println(点击); } public void mousePressed(MouseEvent e) { System.out.println(按下); x1 e.getX(); y1 e.getY(); } public void mouseReleased(MouseEvent e) { System.out.println(松开); x2 e.getX(); y2 e.getY(); int x Math.min(x1, x2); int y Math.min(y1, y2); int w Math.abs(x2 - x1); int h Math.abs(y2 - y1); if (type.equals(直线)) { g.drawLine(x1, y1, x2, y2); } else if (type.equals(矩形)) { g.drawRect(x, y, w, h); } else if (type.equals(圆形)) { g.drawOval(x, y, w, h); } else if (type.equals(实心矩形)) { g.fillRect(x, y, w, h); } else if (type.equals(实心圆形)) { g.fillOval(x, y, w, h); } else if (type.equals(橡皮擦)) { g.setColor(new Color(238, 238, 238)); g.fillOval(x1, y1, 50, 50); g.setColor(color); } else if (type.equals(长方体)) { for (int i 0; i 10; i) { for (int j 0; j 10; j) { if(i6j3j6){ break; } int dx w / 3; int dy h / 2; x i * w; y j * h; g.drawRect(x, y, w, h); g.drawRect(x dx, y - dy, w, h); g.drawLine(x, y, x dx, y - dy); g.drawLine(x w, y, x w dx, y - dy); g.drawLine(x, y h, x dx, y h - dy); g.drawLine(x w, y h, x w dx, y h - dy); } } } else if (type.equals(球形)) { for (int i 0; i w; i) { int cn i; if(cn255){ cn255; } Color c new Color(cn,cn/2,cn); g.setColor(c); g.fillOval(xi/2, yi/2, w-i, h-i); } } else if (type.equals(砖块画)) { int dxw/3; int dyh/2; int[][] arr { {1,0,0,0,1,1,1,0,0,0,1}, {1,0,0,0,1,1,1,0,0,0,1}, {1,0,0,0,1,1,1,0,0,0,1}, {0,0,0,0,0,0,0,0,0,0,0}, {0,0,1,0,0,0,0,0,1,0,0}, {0,0,1,0,0,0,0,0,1,0,0}, {0,0,0,0,0,0,0,0,0,0,0} }; int len arr.length; int len2 arr[0].length; for (int i 0;ilen;i){ for (int j 0;jlen2;j){ if(arr[i][j]0) { Draw3DBox(x1 j * (w 1), y1 - i * (h 1), w, h, dx, dy); } } } } } public void mouseEntered(MouseEvent e) { System.out.println(进入); } public void mouseExited(MouseEvent e) { System.out.println(离开); } }
