Question

java中graphics类划线的问题

public class testframe extends JFrame{

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(300, 200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setLocationRelativeTo(null);

JPanel p=new JPanel();
frame.getContentPane().add(p);
graphics g = new graphics();
p.add(g);
// TODO code application logic here
}

}

class graphics extends JPanel{
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.drawLine(0, 0, 0, 120);
g.setColor(Color.GREEN);
}

}

为什么无论怎么调g.drawLine()中的数 画出来的线总是很短
希望能在原有的程序上进行修改

Answer 1

class testframe extends JFrame {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(300, 200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setLocationRelativeTo(null);

frame.setContentPane(new graphics());
}
}

class graphics extends JPanel {

protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawLine(0, 0, 120, 120);
g.setColor(Color.GREEN);
}
}

Answer 2

g.drawLine(20,20,100,150);你再试试！

追问

连短线都看不到了

追答

(0,0,100,150)

追问

还是短线

追答

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.ImageIcon;
import javax.swing.*;
public class Images {
public static String img;
private int width=100;
private int height=30;
private int codeCount=4;
private int x=0;
private int fontHeight;
private int codeY;
char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K','L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9','a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k','l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z'};
public Images(){
init();
ToImages();
}
public void init()
{
x=width/(codeCount+1);
fontHeight=height-2;
codeY=height-4;
}
BufferedImage ToImages() {
BufferedImage buffImg= new BufferedImage(
width, height,BufferedImage.TYPE_INT_ARGB_PRE);
try {
Graphics2D g = buffImg.createGraphics();
Random random = new Random();
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
g.setFont(font);
g.setColor(Color.BLACK);
g.drawRect(0, 0, width - 1, height - 1);
g.setColor(Color.BLACK);
for(int i = 0; i < 160; i++)
{
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
StringBuffer randomCode = new StringBuffer();
int red = 0, green = 0, blue = 0;
for (int i = 0; i < codeCount; i++) {
String strRand = String.valueOf(codeSequence[random.nextInt(62)]);
red = random.nextInt(255);
green = random.nextInt(255);
blue = random.nextInt(255);
g.setColor(new Color(red, green, blue));
g.drawString(strRand, (i + 1) * x, codeY);
randomCode.append(strRand);
}
img=randomCode.toString();
} catch (Exception e) {
e.printStackTrace();
}
return buffImg;
}