Java 绘制圆形并将其设置为在画布上可见
我有一些代码制作jFrame和canvas。它们是可见的。但我不知道如何设置画布上可见的圆Java 绘制圆形并将其设置为在画布上可见,java,jframe,awt,Java,Jframe,Awt,我有一些代码制作jFrame和canvas。它们是可见的。但我不知道如何设置画布上可见的圆 package unitcirclevisulaization; import java.awt.Canvas; import java.awt.Graphics; import javax.swing.JFrame; public class UnitCircleVisulaization extends Canvas { public s
package unitcirclevisulaization;
import java.awt.Canvas;
import java.awt.Graphics;
import javax.swing.JFrame;
public class UnitCircleVisulaization extends Canvas {
public static void main(String[] args) {
JFrame frame = new JFrame("Unit Circle");
Canvas canvas = new Canvas();
canvas.setSize(800,800);
frame.add(canvas);
frame.pack();
frame.setVisible(true);
}
public void paint(Graphics g)
{
g.fillOval(400, 400, 400, 400);
}
}
我只想在画布上显示一个圆,并能够设置圆的颜色您的paint方法位于UnitCircleVisulaization类中,该类从未实例化,因此从未调用paint方法 要解决此问题,只需更换线路
Canvas canvas = new Canvas();
与
这是因为UnitCircleSulaization扩展了包含paint方法的画布。然后,当框架可见时,将自动调用绘制方法
Canvas canvas = new UnitCircleVisulaization();