所以我有一个大学作业。这个概念是我们要完成一些类层次结构的东西。基本上它是允许我们绘制不同形状的东西。
我可以成功绘制每个形状;我需要它在哪里以及我需要它有多大,就像需要一样......我遇到麻烦的部分是这个复合层次结构。
基本上我们应该有一个新的类,我们应该有一个新的类Compound.java
,我们应该有三个其他类,House
,tree
和earth
; 每个都应该采用我们创建的形状对象(矩形、正方形、直线、椭圆形和圆形)并绘制所需的图片,如类名所示。
我遇到问题的地方是家庭课程;例如:我可以让它绘制一个矩形,但是当我试图让它绘制第二个矩形之后,它基本上忘记了第一个,只绘制了第二个!
我们没有对 Graphics 的东西进行任何练习,所以我不知道任何方法或任何我可以调用来绘制然后在House
构造函数中继续的东西。
我理解为什么它会覆盖第一个矩形,当House
调用构造函数时,它会遍历构造函数中的所有内容,然后返回Compound.java
并使用方法绘制它draw(Graphics g)
....
但我不知道如何解决它!任何帮助将不胜感激......明天到期。
这是所有代码:
形状.java:
import java.awt.*;
public abstract class Shape {
int initX, initY;
Color fillColour;
public Shape() {
initX = 0;
initY = 0;
}
public Shape(int x, int y) {
initX = x;
initY = y;
}
public void setInitX (int x) {
initX = x;
}
public void setInitY (int y) {
initY = y;
}
public abstract void draw(Graphics g);
public abstract double Area();
public abstract double Perimeter();
public void Move(int deltaX, int deltaY){
//future work
}
}
ClosedShape.java:
import java.awt.Graphics;
public abstract class ClosedShape extends Shape {
boolean polygon;
int numPoints;
int[] xVertices;
int[] yVertices;
int x,y,width, height;
public ClosedShape(boolean isPolygon, int numPoints) {
super(0,0);
this.polygon = isPolygon;
this.numPoints = numPoints;
}
public ClosedShape(boolean isPolygon, int numPoints, int[] x, int[] y) {
super(x[0],y[0]);
this.polygon = isPolygon;
if (isPolygon) {
this.numPoints = numPoints;
xVertices = new int[numPoints]; // error check? if x.length == numPoints
for (int i = 0; i < x.length; i++) { // make copy of array: why?
xVertices[i] = x[i];
}
yVertices = new int[numPoints]; // error check? if y.length == numPoints
for (int i = 0; i < y.length; i++) { // make copy of array
yVertices[i] = y[i];
}
}
else { // its an oval - define bounding box
this.numPoints = 4;
this.x = x[0];
this.y = y[0];
width = x[1];
height = y[1];
}
}
public void setXYCoords(int[] x, int[] y){
this.xVertices = x;
this.yVertices = y;
}
// Gives access to the width attribute
public void setWidth(int width){
this.width = width;
}
// Gives access to the height attribute
public void setHeight(int height) {
this.height = height;
}
public void draw(Graphics g) {
if (polygon) {
g.drawPolygon(xVertices, yVertices, numPoints);
}
else {
g.drawOval(x, y, width, height);
}
}
public abstract double Area();
public abstract double Perimeter();
}
矩形.java:
public class Rectangle extends ClosedShape
{
public Rectangle(int x, int y, int width, int height)
{
super(true, 4);
setWidth(width);
setHeight(height);
int [] arrayX = new int[4];
arrayX[0] = x;
arrayX[1] = (x+width);
arrayX[2] = (x+width);
arrayX[3] = x;
int [] arrayY = new int[4];
arrayY[0] = y;
arrayY[1] = y;
arrayY[2] = y+height;
arrayY[3] = y+height;
setXYCoords(arrayX, arrayY);
}
public double Area()
{
return 0;
}
public double Perimeter()
{
return 0;
}
}
复合.java:
import java.awt.*;
import java.awt.Graphics;
public class Compound
{
boolean polygon;
int[] xVertices;
int[] yVertices;
int initX, initY;
Color fillColour;
public void setXYCoords(int[] x, int[] y)
{
this.xVertices = x;
this.yVertices = y;
}
public void draw(Graphics g)
{
if (polygon) {
g.drawPolygon(xVertices, yVertices, 4);
}
else {
g.drawOval(1, 1, 1, 1);
}
}
}
房子.java:
import java.awt.*;
import java.awt.Graphics;
public class House extends Compound
{
public House(int x, int y, int width, int height)
{
int [] arrayX = new int[4];
arrayX[0] = x;
arrayX[1] = (x+width);
arrayX[2] = (x+width);
arrayX[3] = x;
int [] arrayY = new int[4];
arrayY[0] = y;
arrayY[1] = y;
arrayY[2] = y+height;
arrayY[3] = y+height;
setXYCoords(arrayX, arrayY);
this.polygon = true;
Rectangle house = new Rectangle(x, y, width, height);
int [] arrayXTwo = new int[4];
arrayXTwo[0] = x+(width/4);
arrayXTwo[1] = x+(2*(width/4));
arrayXTwo[2] = x+(2*(width/4));
arrayXTwo[3] = x+(width/4);
int [] arrayYTwo = new int[4];
arrayYTwo[0] = y+(height/4);
arrayYTwo[1] = y+(height/4);
arrayYTwo[2] = y+height;
arrayYTwo[3] = y+height;
setXYCoords(arrayXTwo, arrayYTwo);
this.polygon = true;
Rectangle door = new Rectangle(x, y, width, height);
}
}