如题,代码如下
class MyPanel extends JPanel {
@Override
protected void printComponent(Graphics g) {
super.printComponent(g);//清屏,防止闪屏
this.setBackground(Color.BLACK);
System.out.println("paintComponent已运行");
}
}
class FrameLearn {
public static void main(String[] args){
JFrame frame = new JFrame("Titel");
frame.setBounds(300,300,900,720);
frame.add(new MyPanel());
frame.setResizable(false);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
正常来说不应该在我构造MyPanel的时候printComponent就自动运行了吗
不管怎么弄,就是不运行,那句话也无法输出
方法名写错了,是paintComponent()方法,而不是printComponent()方法。修改如下:
参考链接:
JPanel容器调用paintComponents(Graphics g)方法_香樟依旧的博客-CSDN博客
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
class MyPanel extends JPanel {
@Override
protected void paintComponent(Graphics g) {
//super.printComponent(g);//清屏,防止闪屏,这一句要去除,否则运行时会报错
this.setBackground(Color.BLACK);
System.out.println("paintComponent已运行");
}
}
class FrameLearn {
public static void main(String[] args){
JFrame frame = new JFrame("Titel");
frame.setBounds(300,300,900,720);
frame.add(new MyPanel());
frame.setResizable(false);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}