java - java中从数组平铺 map

Question

我正在尝试迭代 2D 整数数组，以使用 Java 的 Graphics2D 生成平铺 map 。

    int[][] mapArray = {{1, 1, 1, 1, 1, 1, 1, 1},
                    {1, 0, 0, 0, 0, 0, 0, 1},
                    {1, 0, 0, 0, 0, 0, 0, 1},
                    {1, 0, 0, 0, 0, 0, 0, 1},
                    {1, 0, 0, 0, 0, 0, 0, 1},
                    {1, 1, 1, 1, 1, 1, 1, 1}};

    public void draw(Graphics2D g2d){
    for(int y = 0; y < mapArray.length; y++){
        for(int x = 0; x < mapArray[0].length; x++){
            if(mapArray[x][y] == 1){
                 ImageIcon ic = new ImageIcon("/Textures/stone.jpg");
                 g2d.drawImage(ic.getImage(), x, y, null);
            }
            else if(mapArray[x][y] == 0){
                 ImageIcon ic = new ImageIcon("/Textures/water.jpg");
                 g2d.drawImage(ic.getImage(), x, y, null);
            }

我似乎无法理解迭代二维数组的逻辑。理想情况下，每个 0 代表水砖，而每个 1 代表石砖。每次运行此程序时，我都会收到 NullPointerException。

Answer 1

x 和 y 方向错误

public void draw(Graphics2D g2d){
    for(int y = 0; y < mapArray.length; y++){
        for(int x = 0; x < mapArray[y].length; x++){ //you want to use y here not 0
            if(mapArray[y][x] == 1){                 //first box is outer array second is inner one
                ImageIcon ic = new ImageIcon("/Textures/stone.jpg");
                g2d.drawImage(ic.getImage(), x, y, null);
            } else if(mapArray[y][x] == 0){
                ImageIcon ic = new ImageIcon("/Textures/water.jpg");
                g2d.drawImage(ic.getImage(), x, y, null);
            }
        }
    }
}