矩形的用户输入值

Question

我有一个类，用户输入完美矩形左上角的 x 和 y 坐标，以及长度和宽度。 RectangleViewer 构造函数将矩形设置为空，然后将所有变量设置为 0。

这是我目前所拥有的：

public class RectangleViewer {
    private Rectangle rectangle;
    private Scanner input = new Scanner(System.in);

    public RectangleViewer() {
        this.rectangle = null;
        this.rectangle = new Rectangle(new Point2D.Double(0.0, 0.0), 0.0, 0.0);
    }

    public void inputRectangleParameters() {
        System.out.print("Please enter the x coordinate of the top left point of the rectangle: ");
        double xCoordinate;
        xCoordinate = input.nextDouble();
    
        System.out.print("Please enter the y coordinate of the top left point of the rectangle: ");
        double yCoordinate;
        yCoordinate = input.nextDouble();
    
        System.out.print("Please enter the length of the rectangle: ");
        double inputLength;
        inputLength = input.nextDouble();
    
        System.out.print("Please enter the width of the rectangle: ");
        double inputWidth;
        inputWidth = input.nextDouble();
    }

    public void initializeRectangle() {
        this.rectangle = new Rectangle(new Point2D.Double(inputRectangle());
    }
}

这是 Rectangle 类本身的代码：

public class Rectangle {
    private double width;
    private double length;
    private Point2D.Double topLeftPoint;

    public Rectangle(Point2D.Double topLeftPoint, double width, double length) {
        this.width = width;
        this.length = length;
        this.topLeftPoint = topLeftPoint; 
    }

我将如何设置它，以便将 inputRectangleParameters 中的值分配给将在 initializeRectangle 中创建的矩形？

Answer 1

inputRectangleParameters 方法从命令行读取值。如果您希望在initializeRectangle 方法中创建矩形，则需要将读取的值传递给它。

这可以通过例如返回对象中的值。 由于 Rectangle 类包含值的相应属性，我建议在输入法中创建一个矩形对象并将其返回以进行初始化。

public Rectangle inputRectangleParameters() {
    System.out.print("Please enter the x coordinate of the top left point of the rectangle: ");
    double xCoordinate;
    xCoordinate = input.nextDouble();

    System.out.print("Please enter the y coordinate of the top left point of the rectangle: ");
    double yCoordinate;
    yCoordinate = input.nextDouble();

    System.out.print("Please enter the length of the rectangle: ");
    double inputLength;
    inputLength = input.nextDouble();

    System.out.print("Please enter the width of the rectangle: ");
    double inputWidth;
    inputWidth = input.nextDouble();

    return new Rectangle(new Point2D.Double(xCoordinate,yCoordinate),inputWidth,inputLength);
}

public void initializeRectangle() {
    this.rectangle = inputRectangleParameters();
}

一个不太干净的版本是返回例如具有特定值位置的值数组。

public double[] inputRectangleParameters() {
    System.out.print("Please enter the x coordinate of the top left point of the rectangle: ");
    double xCoordinate;
    xCoordinate = input.nextDouble();

    System.out.print("Please enter the y coordinate of the top left point of the rectangle: ");
    double yCoordinate;
    yCoordinate = input.nextDouble();

    System.out.print("Please enter the length of the rectangle: ");
    double inputLength;
    inputLength = input.nextDouble();

    System.out.print("Please enter the width of the rectangle: ");
    double inputWidth;
    inputWidth = input.nextDouble();

    return new double[]{xCoordinate, yCoordinate, inputWidth, inputLength};
}

public void initializeRectangle() {
    final double[] rectangleParameters = inputRectangleParameters();
    this.rectangle = new Rectangle(new Point2D.Double(rectangleParameters[0], rectangleParameters[1]), rectangleParameters[2], rectangleParameters[3]);
}