如何在挥杆中制造障碍

Question

我想在Java中用红色创建这个障碍

class Grid extends JFrame{
    public Grid(){
        setResizable(false);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(250,300);
        // Set the width,height,number of rows and columns
        final GridPanel panel = new GridPanel(300, 300, 10, 10);
        add(panel);
    }
}
class GridPanel22 extends JPanel{
    int width, height, rows, columns;
    int gridWidth, gridHeight;
    public GridPanel22(int width, int height, int rows, int columns){
        gridHeight = height / rows;
        gridWidth = width / columns;
        setPreferredSize(new Dimension(width, height));
    }
    public void paint(Graphics g){

        g.setColor(Color.red);
        for (int i = 1; i <= rows; i++) {
            g.drawLine(0, i * gridHeight, width, i * gridHeight);
        }
        for (int j = 1; j <= columns; j++) {
            g.drawLine(j * gridWidth, 0, j * gridWidth, height);
        }
    }
}

此代码创建了一个网格，但我无法创建障碍。在图片中，那些红色细胞是障碍细胞。为了区分正常网格和主网格，我用红色绘制它。 。我知道在java中有一个名为drawRect()的函数，但我不确定它是如何工作的。按照图片，从grid（1,1）开始到结束它（5,4）有一个障碍。现在将这些细胞作为障碍细胞，我想将1（一）分配给所有那些细胞意味着（1,1） - > 1，然后（2,1） - > 1 ......（5， 4） - > 1等因此，当我的机器人从一个单元格移动到另一个单元格时，它可以避开这些单元格并找到它自己的去往目的地的路径。

Answer 1

请注意代码中的注释：

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

class Grid extends JFrame{

    public Grid(){
        setResizable(false);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        final GridPanel panel = new GridPanel(300, 300, 4, 4);
        panel.setColor(1, 1, Color.RED); //change cell colors 
        panel.setColor(2, 3, Color.RED);
        add(panel);
        pack();
        setVisible(true);
    }
}

class GridPanel extends JPanel{

    //store reference to each cells
    Component[][] cells;

    public GridPanel (int width, int height, int rows, int columns){

        cells = new Component[rows][columns];
        //use grid layout to get the layout you want 
        setLayout(new GridLayout(rows, columns));
        setPreferredSize(new Dimension(width, height));
        for(int row =0; row < rows; row ++){
            for(int col =0; col < columns; col ++){
                Component cell = getCell();
                cells[row][col] = cell;
                add(cell);
            }
        }
    }

    //represent each cell as a label 
    Component getCell() {
        JLabel label = new JLabel();
        label.setBackground(Color.WHITE);
        label.setOpaque(true);
        label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
        return label;
    }

    //control color of each cell 
    void setColor(int row, int col, Color color) {
        cells[row][col].setBackground(color);
    }

    public static void main(String[] args) { new Grid();    }
}

如有需要，请随时要求澄清。

Answer 2

您唯一的问题是您没有为传递给构造函数的值分配字段：

public GridPanel22(int width, int height, int rows, int columns) {
    this.width = width;
    this.height = height;
    this.rows = rows;
    this.columns = columns;
    gridHeight = height / rows;
    gridWidth = width / columns;
    setPreferredSize(new Dimension(width, height));
}

另外，改变

final GridPanel panel = new GridPanel(300, 300, 10, 10);

至

final GridPanel22 panel = new GridPanel22(300, 300, 10, 10);