Question

所以我有一个大学的任务。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。

我可以成功地绘制每个形状;我需要的地方和我需要它有多大，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名为Compound.java的新类，并且我们应该有另外三个类，House，tree和earth ;每个都应该采取我们创建的形状对象（矩形，正方形，线形，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在上课;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，它基本上会忘记第一个矩形并且只绘制第二个矩形！

我们没有对Graphics的任何练习，所以我不知道任何方法或任何我可以调用绘制然后继续House构造函数。

我理解为什么它会覆盖第一个矩形，当调用House构造函数时，它会遍历构造函数中的所有内容，然后返回到Compound.java并使用{来绘制它{1}}方法......

但我不知道如何解决它！任何帮助将不胜感激......它将于明天到期。

以下是所有代码：

Shape.java：

draw(Graphics g)

ClosedShape.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
    }

}

Rectangle.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();








}

Compound.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;
    }

}

House.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);
        }

    }

}

Answer 1

从示例代码中，无法向Compound类“添加”任何形状。根据您的描述，Compound应该是形状的“容器”。更多的东西......

public class Compound
{
    private List<Shape> shapes;

    public Compound() {
        shapes = new ArrayList<Shape>(25);
    }

    public void addShape(Shape shape) {
        shapes.add(shape);
    }

    public Iterable<Shape> getShapes() {
        return shape;
    }

    public void draw(Graphics g) {
        for (Shape shape : shapes) {
            shape.draw(g);
        }
    }
}

现在你需要决定，如果为形状本身定义Color和Shape，最好将它关联在哪里？这意味着您无法重复使用该形状。或者使用Compound形状？

绘图问题 - 从其他形状中绘制复合形状

1 个答案: