日期:2014-05-20  浏览次数:20724 次

java Arc2D问题求助
请问下用Arc2D.Double(double   x,   double   y,   double   w,   double   h,   double   start,   double   extent,   int   type)   中的w,h是外围矩形的长和宽嘛?那若已知的是一条圆弧的起始点,起始角度,终止角度,和半径,怎么来求w,h那?
先谢过各位。

------解决方案--------------------
w - 完整椭圆的总宽度,此弧是该椭圆的一部分。
h - 完整椭圆的总高度,此弧是该椭圆的一部分。

如果你知道半径了,那么w,h就是他们的2倍.(-_-!直径)
要是圆弧,相等就是了...

a sample:

Java code
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;

public class Test73 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        JFrame frame = new DrawFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

class DrawFrame extends JFrame {
    public DrawFrame() {
        // TODO Auto-generated constructor stub
        setTitle("DrawArc");
        setSize(200, 200);
        add(new DrawPanel());
    }
}

class DrawPanel extends JPanel {
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;    
        g2.draw(new Arc2D.Double(40, 50, 100, 50, 0, 60, Arc2D.OPEN));
        g2.draw(new Arc2D.Double(40, 50, 100, 50, 120, 60, Arc2D.OPEN));
        g2.draw(new Arc2D.Double(40, 50, 100, 50, 240, 60, Arc2D.OPEN));
        
        /*g2.draw(new Arc2D.Double(40, 50, 100, 50, 0, 60, Arc2D.PIE));
        g2.draw(new Arc2D.Double(40, 50, 100, 50, 120, 60, Arc2D.PIE));
        g2.draw(new Arc2D.Double(40, 50, 100, 50, 240, 60, Arc2D.PIE));*/
    }
}