Question

我想在JPanel上绘制一些内容，但似乎我遇到了paint和paintComponent方法的问题。可能与双缓冲有关，但我不确定。 public void paintComponent(Graphics g)方法由于某种原因没有被调用，任何想法为什么？

这是我的代码：

   @Override
public void paintComponents(Graphics g) {
    super.paintComponents(g); //To change body of generated methods, choose Tools | Templates.
    System.out.println("paintComponents!");

    snakeHead.DrawSphere(g);

    if(foodShoulBeRedrawn){
        foodShoulBeRedrawn = false;
        spawnFood();
    }

    if(shouldSpawnBodyPart){
        shouldSpawnBodyPart = false;
        snake.get(snake.size() - 1).DrawSphere(g);

    }

    //spawnSnake();
    paintCalled = true;

    repaint();
}

/*
@Override
public void paint(Graphics g) {
    super.paint(g);

    snakeHead.DrawSphere(g);

    if(foodShoulBeRedrawn){
        foodShoulBeRedrawn = false;
        spawnFood();
    }

    if(shouldSpawnBodyPart){
        shouldSpawnBodyPart = false;
        snake.get(snake.size() - 1).DrawSphere(g);

    }

    //spawnSnake();
    paintCalled = true;

    repaint();
}
*/

Answer 1

您将覆盖JFrame继承的Container#paintComponents()。您需要扩展JPanel，而不是扩展JFrame，以便覆盖其paintComponent()和getPreferredSize()。然后，您可以add()将小组设为JFrame，就像他们显示here和here一样。

Answer 2

我认为JFrame不是JComponent，因此永远不会调用paintComponent方法。您应该将所有绘制方法放在JPanel中并将其包含在JFrame中。

Java paintComponents未被调用

2 个答案: