在Java小程序中绘制多边形

多边形是一个封闭的图形，有一组有限的线段将一个顶点连接到另一个顶点。多边形由一组（x，y）坐标对组成，每对坐标对都是多边形的顶点。多边形的边是在两个连续的坐标对之间绘制的线，从第一对到最后一对绘制一条线段。

我们可以通过三种方式在java applet中绘制多边形：

1. drawPolygon（int[]x，int[]y，int numberofpoints）： 使用给定的x和y点集绘制多边形。

   // Java program to draw polygon using // drawPolygon(int[] x, int[] y, int numberofpoints) // function import java.awt.*; import javax.swing.*; public class poly extends JApplet { // called when applet is started public void init() { // set the size of applet to 300, 300 setSize( 200 , 200 ); show(); } // invoked when applet is started public void start() { } // invoked when applet is closed public void stop() { } public void paint(Graphics g) { // x coordinates of vertices int x[] = { 10 , 30 , 40 , 50 , 110 , 140 }; // y coordinates of vertices int y[] = { 140 , 110 , 50 , 40 , 30 , 10 }; // number of vertices int numberofpoints = 6 ; // set the color of line drawn to blue g.setColor(Color.blue); // draw the polygon using drawPolygon function g.drawPolygon(x, y, numberofpoints); } }

   输出：

2. drawPolygon（多边形p）： 使用多边形类的给定对象绘制多边形。

   // Java program to draw polygon // using drawPolygon(Polygon p) // function import java.awt.*; import javax.swing.*; public class poly extends JApplet { // called when applet is started public void init() { // set the size of applet to 300, 300 setSize( 200 , 200 ); show(); } // invoked when applet is started public void start() { } // invoked when applet is closed public void stop() { } public void paint(Graphics g) { // x coordinates of vertices int x[] = { 10 , 30 , 40 , 50 , 110 , 140 }; // y coordinates of vertices int y[] = { 140 , 110 , 50 , 40 , 30 , 10 }; // number of vertices int numberofpoints = 6 ; // create a polygon with given x, y coordinates Polygon p = new Polygon(x, y, numberofpoints); // set the color of line drawn to blue g.setColor(Color.blue); // draw the polygon using drawPolygon // function using object of polygon class g.drawPolygon(p); } }

   输出：

3. 抽绳（点x、点y、点x1、点y1）： 在这种方法中，我们将用一条线段连接相邻顶点，并连接第一个和最后一个顶点。

   // Java code to draw a polygon // using  drawLine(int x, int y, int x1, int y1) // function import java.awt.*; import javax.swing.*; public class poly extends JApplet { // called when applet is started public void init() { // set the size of applet to 300, 300 setSize( 200 , 200 ); show(); } // invoked when applet is started public void start() { } // invoked when applet is closed public void stop() { } public void paint(Graphics g) { // x coordinates of vertices int x[] = { 10 , 30 , 40 , 50 , 110 , 140 }; // y coordinates of vertices int y[] = { 140 , 110 , 50 , 40 , 30 , 10 }; // number of vertices int numberofpoints = 6 ; // set the color of line drawn to blue g.setColor(Color.blue); // join the adjacent vertices for ( int i = 0 ; i < numberofpoints - 1 ; i++) g.drawLine(x[i], y[i], x[i + 1 ], y[i + 1 ]); // join the first and last vertex g.drawLine(x[ 0 ], y[ 0 ], x[numberofpoints - 1 ], y[numberofpoints - 1 ]); } }

   输出：

注： 上述函数是java的一部分。awt包，属于java。awt。图形课。此外，这些代码可能不会在联机编译器中运行。请使用脱机编译器。程序员可以根据需要更改x和y坐标