public class aa
{
JFrame jf;
aa()
{
jf=new JFrame();
jf.setSize(300,300);
jf.addMouseListener(new MouseAdapter()
{
public void mouseClicked(MouseEvent e)
{
jf.getGraphics().setColor(Color.red);
jf.getGraphics().fillRect(30,30, 30, 30);
}
});
jf.setVisible(true);
}
public static void main(String[] args)
{
new aa();
}
}
为什么单击鼠标后 显示的矩形 不是我设置的颜色
{
JFrame jf;
aa()
{
jf=new JFrame();
jf.setSize(300,300);
jf.addMouseListener(new MouseAdapter()
{
public void mouseClicked(MouseEvent e)
{
jf.getGraphics().setColor(Color.red);
jf.getGraphics().fillRect(30,30, 30, 30);
}
});
jf.setVisible(true);
}
public static void main(String[] args)
{
new aa();
}
}
为什么单击鼠标后 显示的矩形 不是我设置的颜色
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class aa { JFrame jf; aa() {
jf = new JFrame();
jf.setSize(300, 300);
jf.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) {
Graphics g=jf.getGraphics();
g.setColor(Color.red);
g.fillRect(30, 30, 30, 30);
}
});
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.setVisible(true);
} public static void main(String[] args) {
new aa();
}
}