Java - 调用paintComponent方法

Question

我想要一个可以通过使用给定的 x、y、颜色参数调用其方法来重新创建的圆。但我很难这样做。我想将 JComponent 用作对象而不是组件。

public class OlympicRingsComponent extends JComponent {

public void paintComponent(Graphics g) {

    super.paintComponent(g);

    Graphics2D g2 = (Graphics2D)g;
    g2.translate(10, 10);
    g2.setStroke(new BasicStroke(7));

    Ellipse2D.Double circle = new Ellipse2D.Double(0,0,100,100);

    g2.setPaint(Color.BLUE);
    g2.draw(circle);

}}

这段代码工作正常。但我希望能够调用一个方法来创建一个新的椭圆。

public class OlympicRingsComponent extends JComponent {

protected void paintComponent(Graphics g) {

    super.paintComponent(g);

    Graphics2D g2 = (Graphics2D)g;
    g2.translate(10, 10);
    g2.setStroke(new BasicStroke(7));

    ring(10 , 20 , "Blue");

}
public void ring(int x , int y , String color) {
    Ellipse2D.Double circle = new Ellipse2D.Double( x , y ,100,100);

    g2.setPaint(Color.getColor(color));
    g2.draw(circle);
}}

Answer 1

需要向 ring() 方法添加 graphics2D 参数，如下所示:

public void ring(int x , int y , String color, graphics2D g2) {
    Ellipse2D.Double circle = new Ellipse2D.Double( x , y ,100,100);

    g2.setPaint(Color.getColor(color));
    g2.draw(circle);
}

并使用graphics2D参数调用ring():

ring(10 , 20 , "Blue", g2);

我认为这应该有效。