手机网站跳转代码企业如何做好网络营销

思路：
①画图板的界面
②创建监听器类
③给按钮加上鼠标监听
③画图版的重绘

第一部分：界面类
①画图板的界面 ③给按钮加上鼠标监听

public class SampleDraw extends JFrame {public static void main(String[] args) {SampleDraw sam = new SampleDraw();//创建该类对象sam.showUI();//调用showUI方法}public void showUI() {this.setSize(800, 600);//设置尺寸this.setTitle("画板v1.0");//设置标题this.setLocationRelativeTo(null);//设置居中this.setDefaultCloseOperation(3);//设置关闭进程FlowLayout flow = new FlowLayout();//布局方式为流式布局this.setLayout(flow);Color[] color = { Color.GREEN, Color.RED, Color.BLUE, Color.YELLOW };//创建一个数组保存颜色DrawListener drawListener = new DrawListener();//新建监听器对象for (int i = 0; i < color.length; i++) {//利用循环将颜色依次将赋给按钮的背景色JButton jbu = new JButton();jbu.setPreferredSize(new Dimension(30, 30));//设置按钮尺寸jbu.setBackground(color[i]);//设置按钮的背景色this.add(jbu);//把按钮加给窗体jbu.addActionListener(drawListener);//给按钮添加监听器}String[] name = { "直线", "三角形", "正方形","矩形", "椭圆","棱形", "五边形", "图片1", "图片2", "画笔", "特殊三角形", "多边形" };创建一个数组保存按钮名称for (int i = 0; i < name.length; i++) {//利用循环将名字赋给按钮JButton jbu1 = new JButton(name[i]);//创建按钮对象this.add(jbu1);//把按钮对象加给窗体jbu1.addActionListener(drawListener);//给按钮添加监听器}this.setVisible(true);  //设置窗体可见Graphics g = this.getGraphics();//创建画笔this.addMouseListener(drawListener);//添加鼠标监听器this.addMouseMotionListener(drawListener);//添加鼠标拖动监听器drawListener.setGr(g);//调用监听器的set方法drawListener.setShape(listshape);//调用监听器的setShape方法}
}

第二部分：监听器类
②创建监听器
该类应该继承MouseListener, ActionListener, MouseMotionListener的接口

public class DrawListener implements MouseListener, ActionListener, MouseMotionListener {private Graphics gr;//声明对象private Color color;private int flag = 1;private String name;private int x1, y1, x2, y2, x3, y3,x4,y4;private ImageIcon icon = new ImageIcon("C:\\Users\\Administrator\\Pictures\\lu.jpg");//添加图片。注意路径为绝对路径，单斜杠变成双斜杠，加文件名和后缀格式private ImageIcon icon2 = new ImageIcon("C:\\Users\\Administrator\\Pictures\\hua.jpg");private ArrayList<Shape> listshape;public void setGr(Graphics g) {//传画笔gr = g;}public void setShape(ArrayList<Shape> listshape) {//传数组this.listshape = listshape;}public void actionPerformed(ActionEvent e) {//监听方法if ("".equals(e.getActionCommand())) {//如果按钮的文本内容为""JButton jbu = (JButton) e.getSource();color = jbu.getBackground();//获取按钮的背景色gr.setColor(color);} else {//按钮文本内容不为空name = e.getActionCommand();//将按钮的文本内容赋给name}}public void mouseDragged(MouseEvent e) {x3 = e.getX();//x3  y3 为鼠标按压拖动时的坐标y3 = e.getY();if ("画笔".equals(name)) {//如果点击是“画笔”按钮gr.drawLine(x1, y1, x3, y3);//画线x1 = x3;y1 = y3;
//          更新x1,y1的值，把每一个点依次相连。}}public void mouseMoved(MouseEvent e) {}public void mouseClicked(MouseEvent e) {x4 = e.getX();//将鼠标点击时的坐标赋给x4,y4y4 = e.getY();if ("特殊三角形".equals(name) && flag == 2) {//此时flag为2时，才能将点击的点和直线的两端链接起来gr.drawLine(x1, y1, x4, y4);//画线gr.drawLine(x2, y2, x4, y4);flag = 1;//画完线后，将flag的值赋为1，这样能接着画第二个三角形}if ("多边形".equals(name) && flag == 2) {gr.drawLine(x2, y2, x4, y4);x2 = x4;y2 = y4;if (e.getClickCount() == 2) {//如果为双击gr.drawLine(x1, y1, x4, y4);flag = 1;}}}public void mousePressed(MouseEvent e) {if (flag == 1) {x1 = e.getX();y1 = e.getY();}}public void mouseReleased(MouseEvent e) {if (flag == 1) {x2 = e.getX();y2 = e.getY();}if ("直线".equals(name)) {gr.drawLine(x1, y1, x2, y2);}if ("矩形".equals(name)) {gr.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));}if ("椭圆".equals(name)) {gr.drawOval(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));}if ("三角形".equals(name)) {int[] xPoints = new int[] { x1, Math.abs((x1 + x2) / 2), x2 };int[] yPoints = new int[] { y2, y1, y2 };int nPoints = 3;gr.drawPolygon(xPoints, yPoints, nPoints);}if ("图片1".equals(name)) {gr.drawImage(icon.getImage(), Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2),null);}if ("图片2".equals(name)) {gr.drawImage(icon2.getImage(), Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2),null);}if ("正方形".equals(name)) {gr.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(x1 - x2));}if ("棱形".equals(name)) {int[] xPoints = new int[] { (x1 + x2) / 2, x2, (x1 + x2) / 2, x1 };int[] yPoints = new int[] { y2, (y1 + y2) / 2, y1, (y1 + y2) / 2 };int nPoints = 4;gr.drawPolygon(xPoints, yPoints, nPoints);}if ("五边形".equals(name)) {int[] xPoints = new int[] { (x1 + x2) / 2, x2, x2 - (x2 - x1) / 4, x1 + (x2 - x1) / 4, x1 };int[] yPoints = new int[] { y1, (y1 + y2) / 2, y2, y2, (y1 + y2) / 2 };int nPoints = 5;gr.drawPolygon(xPoints, yPoints, nPoints);}if ("特殊三角形".equals(name) && flag == 1) {gr.drawLine(x1, y1, x2, y2);flag++;}if ("多边形".equals(name) && flag == 1) {gr.drawLine(x1, y1, x2, y2);flag++;}}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}
}

现在就实现了简单的画图版了，但是会有一个问题，当我们改变窗体的大小或者最小化窗体再打开来会发现，之前画的图都不见了。这是因为当窗体发生改变时，程序会重新从内存中获取更新后的数据绘制。我们没有将画过的形状存放到内存中，当窗体发生重绘的时候，就不会绘制了

第三步：画图板的重绘
定义一个Shape类。
其中定义一个队列，用于存放图形对象。（队列的大小随对象的增加而增加）

public class Shape {private String name;private Color color; private int x1, x2, y1, y2 ;private ImageIcon icon = new ImageIcon("C:\\Users\\Administrator\\Pictures\\lu.jpg");private ImageIcon icon2 = new ImageIcon("C:\\Users\\Administrator\\Pictures\\hua.jpg");public void setShape(int x1, int y1, int x2, int y2, String name, Color color) {this.x1 = x1;this.x2 = x2;this.y1 = y1;this.y2 = y2;this.name = name;this.color = color;}public void drawShape(Graphics g) {switch (name) {case "直线":g.setColor(color);g.drawLine(x1, y1, x2, y2);break;case "矩形":g.setColor(color);g.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));break;case "椭圆":g.setColor(color);g.drawOval(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));break;case "三角形":g.setColor(color);int[] xPoints = new int[] { x1, Math.abs((x1 + x2) / 2), x2 };int[] yPoints = new int[] { y2, y1, y2 };int nPoints = 3;g.drawPolygon(xPoints, yPoints, nPoints);break;case "画笔":g.setColor(color);g.drawLine(x1, y1, x2, y2);break;case "正方形":g.setColor(color);g.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(x1 - x2));break;case "五边形":g.setColor(color);int[] xPoints1 = new int[] { (x1 + x2) / 2, x2, x2 - (x2 - x1) / 4, x1 + (x2 - x1) / 4, x1 };int[] yPoints1 = new int[] { y1, (y1 + y2) / 2, y2, y2, (y1 + y2) / 2 };int nPoints1 = 5;g.drawPolygon(xPoints1, yPoints1, nPoints1);break;case "棱形":g.setColor(color);int[] xPoints2 = new int[] { (x1 + x2) / 2, x2, (x1 + x2) / 2, x1 };int[] yPoints2 = new int[] { y2, (y1 + y2) / 2, y1, (y1 + y2) / 2 };int nPoints2 = 4;g.drawPolygon(xPoints2, yPoints2, nPoints2);break;case "特殊三角形":g.setColor(color);g.drawLine(x1, y1, x2, y2);break;case "多边形":g.setColor(color);g.drawLine(x1, y1, x2, y2);break;case"图片1":g.setColor(color);g.drawImage(icon.getImage(), x1,y1,x2,y2,null);break;case"图片2":g.setColor(color);g.drawImage(icon2.getImage(), x1,y1,x2,y2,null);break;}}
}

再在监听器类中，画一个图形就将图形存入Shape类中的队列中去。例如：

if ("直线".equals(name)) {gr.drawLine(x1, y1, x2, y2);Shape shape = new Shape();shape.setShape(x1, y1, x2, y2, name, color);listshape.add(shape) ;}

最后在主界面的类中去定义重绘的方法和调用。在重绘方法中将队列中的对象取出来，调用画的方法

public void paint(Graphics g) {//重绘方法super.paint(g);//进行重绘for (int i = 0; i < listshape.size(); i++) {Shape shape = listshape.get(i);//依次取出对象if (shape != null) {shape.drawShape(g);//调用对象的画的方法} else {break;}}}

图形的重绘就到这里啦！