drawarrow.java

使用 java 实现 画简单的 箭头

import java.awt.Graphics;
import java.awt.Graphics2D;

import javax.swing.JFrame;
import javax.swing.JPanel;


public class DrawArrow extends JFrame{
	private JPanel jContentPane = null;
	Graphics g;
	Graphics2D g2;
	public DrawArrow() {
	//	this.mv = mv;
	//	bi = new BufferedImage(256, 256, BufferedImage.TYPE_INT_RGB);
		setSize(400,400);
		this.setVisible(true);
		g=this.getGraphics();
		g2=(Graphics2D)g;
		
		
		repaint();
	//	drawVector();
	}
	
	
	public void paint(Graphics g){
		int X1=120,Y1=120,X0=1,Y0=1,ArrowLen=3;
		double D = Math.abs(Point2D.distance(X1, Y1, X0, Y0)); 
if (D > 0.0000000001 ){ 
Xa = X1 + ArrowLen * ((X0 - X1) + (Y0 - Y1) / 2) / D; 
Ya = Y1 + ArrowLen * ((Y0 - Y1) - (X0 - X1) / 2) / D; 
Xb = X1 + ArrowLen * ((X0 - X1) - (Y0 - Y1) / 2) / D; 
Yb = Y1 + ArrowLen * ((Y0 - Y1) + (X0 - X1) / 2) / D; 
} 

filledTrigon.moveTo((float)X1, (float)Y1); 
filledTrigon.lineTo((float)Xa, (float)Ya); 
filledTrigon.moveTo((float)X1, (float)Y1); 
filledTrigon.lineTo((float)Xb, (float)Yb); 

g.draw(filledTrigon); 
	}
	

	
	public static void main(String args []){
		
		DrawArrow da=new DrawArrow();


	}
	
}