Question

public class Snake {

    // panel width and height
    static int pW; 
    static int pH;

    static int x = 10;
    static int y = 10;

    static int k;

    static JFrame frame = new JFrame("SNAKE");

    // getters for panel class
    public int getPW() { return pW; }
    public int getPH() { return pH; }
    public int getX()  { return x;  }  
    public int getY()  { return y;  }

    public static void main(String[] args) {

        // get screen dimensions
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        int sH = (int) screenSize.getHeight();
        int sW = (int) screenSize.getWidth();

        pW = (int) sW/2;
        pH = (int) sH/2;

        // initialize frame
        frame.setSize    (pW/1,pH/1);
        frame.setLocation(pW/2,pH/2);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.addKeyListener( new KeyAdapter() {

            public void keyPressed(KeyEvent e) {

                k = e.getKeyCode();

                switch(k) {

                case 38: /* y -= square size */ break; // up
                case 40: /* y += square size */ break; // down 
                case 37: /* x -= square size */ break; // left
                case 39: /* x += square size */ break; // right
                case 27: System.exit(0);

                }

            }
        });

        Panel panel = new Panel();

        frame.add(panel);

        frame.setVisible(true);

    }

}

class Panel extends JPanel {

    Snake snake = new Snake();

    //square size and separation between squares
    int sep = 0;
    int size = 50;

    // initial location of square on the panel/frame
    int x = sep + size;
    int y = sep + size;

    // holding values to check if x or y have changed
    int xH = x;
    int yH = x;

    public void paint(Graphics g) {

        int pW = snake.getPW();
        int pH = snake.getPH();

        int i; int o;

        Color on  = Color.BLACK;
        Color off = Color.GRAY;

        // gray background
        g.setColor(Color.GRAY);
        g.fillRect(0,0,pW,pH);

        // black square initialization
        g.setColor(Color.BLACK);
        g.fillRect(x, y, size, size);

        /* this loop is supposed to check if the black
         * rectangle has moved by repeatedly grabbing x & y
         * values from the Snake class. When a key is pressed
         * and the values change, a gray rectangle is placed at the old location 
         * and a black one is placed at the new location.
         * 
         * When I run the program, I get stuck in this while loop.
         * If I had the while loop in the same class I check for keys,
         * I don't think I would have this problem
         */

        while(true) {

            x = snake.getX();
            y = snake.getY();

            if(x != xH || y != yH) {

            g.setColor(off);
            g.fillRect(xH, yH, size, size);
            g.setColor(on);
            g.fillRect(snake.getX(), snake.getY(), size, size);

            xH = x;
            yH = y;

        }}

    }   
}

目前我收到RunTime错误。我的目标是使用DateTime.Now.Year（）测试当前年份是否为闰年。我认为问题是我没有正确地将年份转换为int？请指教。

Answer 1

您可以使用DateTime.IsLeapYear()：

yargs

Answer 2

对于那些遵循规则的人：

根据wikipedia，这些额外的日子每年发生

这是4的整数倍。
年份不是leap年，除非可以被400整除。

因此这将导致以下功能：

// PRE: no year < 1 or > 9999
// POST: true if year is a leap year, or false if not.
public static bool IsLeapYear(int year) 
{
    if (year < 1 || year > 9999) 
    {
        throw new ArgumentOutOfRangeException("year", Environment.GetResourceString("ArgumentOutOfRange_Year"));
    }
    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
}

现在我想知道如果我在卑诗省使用减年-会发生什么？-实际上，问题是哪一个日历甚至甚至适用于1753年（对于英国）？ ;）

Answer 3

我使用 C# 和这段代码来表示闰年。干杯

if ((jahr % 4 == 0 && jahr % 400 == 0) || (jahr % 4 == 0 && !(jahr % 100 == 0)))
{
    Console.WriteLine(jahr + " ist ein Schaltjahr");
}
else
    Console.WriteLine(jahr + " ist kein Schaltjahr");

Answer 4

static int GeveDays()
{
    int days;
    if ((DateTime.Now).Year / 4 != 1 || (DateTime.Now).Year / 400 != 1) {
        Console.WriteLine("it is a common year");
        days = 365;
        return days;
    }
    else if ((DateTime.Now).Year / 100 != 1) {
        Console.WriteLine("it is a leap year");
        days = 366;
        return days;
    }
    else {
        Console.WriteLine("it is a leap year");
        days = 366;
        return days;
    }
}

Answer 5

年财产所以不需要括号......

Answer 6

javapackager -deploy -native -Bcategory=Education -BjvmOptions=-Xmx128m 
    -BjvmOptions=-Xms128m -outdir packages -outfile BrickBreaker -srcdir dist 
    -srcfiles BrickBreaker.jar -appclass brickbreaker.Main -name BrickBreaker 
    -title "BrickBreaker demo"

Thanks,
Gurnur Singh

检查年份是否为闰年

6 个答案: