![JAVA图形不显示!](https://linux22.com/image/875942/JAVA%E5%9B%BE%E5%BD%A2%E4%B8%8D%E6%98%BE%E7%A4%BA%EF%BC%81.png)
我之前发过一篇帖子,但不太清楚!这是代码。这是我正在测试的示例代码,看看它是否适用于我的 ubuntu!
// using drawLine to connect the corners of s panel
import java.awt.Graphics;
import javax.swing.JPanel;
public class DrawPanel extends JPanel
{// draws an x from the corners of the panel
public void paintComponent( Graphics g )
{
// calls paintComponent to ensure the panel displys correctly
super.paintComponent( g );
int width = getWidth();
int height = getHeight();
// draw line from the upper-left to lower-right corners
g.drawLine( 0, 0, width, height );
// draw line from then upper-right to the lower-left corners
g.drawLine( width, 0, 0, height);
System.out.println( "paintComponent Called");
} // end method paintComponent
} // end class DrawPanel
And the driver code:
// application to display a DrawPanel
import javax.swing.JFrame;
public class DrawPanelTest
{
public static void main(String[] args)
{
//create a panel that contains our drawing
DrawPanel panel = new DrawPanel();
// create a new frame to hold the panel
JFrame application = new JFrame("Drawing Diagonals");
// set the frame to exit when closed
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel); // adds panel to the frame
application.setSize(300, 300); // set the size
}
}
当我编译并运行它时,什么都没有显示!它应该弹出一个窗口并显示图形!
它在其他系统上运行良好,但在我的 ubuntu 上却不行!可能出了什么问题?
谢谢
答案1
添加application.setVisible(true);
你的班级DrawPanelTest
public class DrawPanelTest {
public static void main(String[] args) {
// create a panel that contains our drawing
DrawPanel panel = new DrawPanel();
// create a new frame to hold the panel
JFrame application = new JFrame("Drawing Diagonals");
// set the frame to exit when closed
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel); // adds panel to the frame
application.setSize(300, 300); // set the size
application.setVisible(true);
}
}