我无法弄清楚如何在 paintComponent 中使用更改后的变量重新绘制

Question

int club_num = 0;
private int angle = 90;    
private int startX = 72;
private int startY = 329;
private double endX = startX + clublength * Math.sin(Math.toRadians(angle));
private double endY = startY + clublength * Math.cos(Math.toRadians(angle));

@Override
public void paintComponent( Graphics g ){
    super.paintComponent( g );
    g.setColor( Color.BLACK );
    g.drawLine( startX, startY, (int)endX, (int)endY ); //this is what i want to change
} 
public class Keys extends KeyAdapter {
    @Override
    public void keyPressed( KeyEvent e ){
        if ( e.getKeyCode() == KeyEvent.VK_LEFT ){
            club_num--; //ultimately changes endX and endY
            if (club_num < 0)
                club_num = club[0].length-1; //ultimately changes endX and endY
            repaint();
        }
        else if ( e.getKeyCode() == KeyEvent.VK_RIGHT ){
            club_num++; //ultimately changes endX and endY
            if (club_num > club[0].length-1)
                club_num = 0; //ultimately changes endX and endY
            repaint();
        }
    }
}

当按下按钮并更改变量值后调用 repaint() 方法时，我希望行 [g.drawLine( startX, startY, (int)endX, (int)endY )] 根据更新的变量参数 [endX and endY] 进行更改。

Answer 1

找到答案！

我将其添加到我的脚本并将变量更改为 private double endX/endY，并添加了一个计时器对象。

    public class TimerListener implements ActionListener {
      public void actionPerformed(ActionEvent e) {
           calcEndX( clublength, angle );
           calcEndY( clublength, angle );
      }
   }

   public void calcEndX( int clublength, int angle ){
       endX = startX + clublength * Math.sin(Math.toRadians(angle));
   }
   public void calcEndY( int clublength, int angle ){
       endY = startY + clublength * Math.cos(Math.toRadians(angle));
   }
    public double getEndX(){
       return endX;
   }
    public double getEndY(){
       return endY;
   }

我无法弄清楚如何在 paintComponent 中使用更改后的变量重新绘制

I can't figure out how to repaint with altered variables in paintComponent

java

variables

paintcomponent