java GUI编程函数执行顺序问题

oufala 2017-10-18 05:03:22

import javax.swing.*;

import java.awt.*;

import java.io.IOException;

import gui.ZJM;

public class Bresenham extends JPanel {

	private int x0;

	private int y0;

	private int xEnd;

	private int yEnd;

	private boolean temp=false;

	void setyEnd(int i) {

		// TODO 自动生成的方法存根

		yEnd=i;

	}



	 void setxEnd(int i) {

		// TODO 自动生成的方法存根

		xEnd=i;

	}



	 void setY0(int i) {

		// TODO 自动生成的方法存根

		y0=i;

	}



	void setX0(int i) {

		// TODO 自动生成的方法存根

		x0=i;

	}



	//Graphics g=getGraphics();

    @Override

    public void paintComponent(Graphics g) {

        //super.paintComponent(g);

 

        Graphics2D g2d = (Graphics2D)g;

 

        g2d.translate(getWidth() / 2, getHeight() / 2);

        g2d.scale(1, -1); 

        g2d.drawLine(-400, 0, 400, 0);

        g2d.drawLine(0, -400, 0, 400);

        temp=true;

//g2d.drawLine(x0, y0, xEnd, yEnd);

        //Bresline();

	     

    }

    public void setPixel(int x,int y){ 

    	Graphics g = getGraphics();

    	 Graphics2D g2d = (Graphics2D)g;    	 

         g2d.translate(getWidth() / 2, getHeight() / 2);

         g2d.scale(1, -1); 

    	g2d.setColor(Color.RED);

    	g2d.fillOval(x,y,1,1);

    	  }

    static void createAndShowGUI(Bresenham a) {

        JFrame frame = new JFrame();

 

        // Add your component.



        frame.setContentPane(a);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setSize(700, 400);

        frame.setLocationRelativeTo(null);

        frame.setVisible(true);

    }

    public void Bresline(){

    	int dx=Math.abs(xEnd-x0),dy=Math.abs(yEnd-y0);

    	int p=2*dy-dx;

    	int twoDy=2*dy,twoDyMinusDx = 2*(dy-dx);

    	int x,y;

    	

    	if(x0>xEnd) {

    		x=xEnd;

    		y=yEnd;

    		xEnd=x0;}

    	else {

    		x=x0;

    		y=y0;

    	}

    	setPixel(x,y);

    	while(x<xEnd) {

    		x++;

    		if(p<0)

    			p+=twoDy;

    		else {

    			y++;

    			p+=twoDyMinusDx;

    		}

    		setPixel(x,y);

    		try {

	    		 Thread.currentThread().sleep(250);

	    	 }

	    	 catch(Exception e){} 

    	}

   

    }

    public void bresline(int x0,int y0,int xEnd,int yEnd) {

    	Bresenham a = new Bresenham();

 		a.setX0(x0);

 		a.setY0(y0);

 		a.setxEnd(xEnd);

 		a.setyEnd(yEnd);

   	a.createAndShowGUI(a);

   	a.Bresline();

    }

    public static void main(String[] args) throws IOException {

    	 

    }

}