public class myFrame extends Frame {
Graphics g; int x, y, ox, oy; public myFrame(String title) {
super(title);
setSize(200, 200);
g = getGraphics();//这里为什么获得不到
g.setColor(Color.red); addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
g.drawLine(ox, oy, x, y);
ox = x;
oy = y;
}
}); addMouseMotionListener(new MouseMotionAdapter() {
public void mousePressed(MouseEvent e) {
ox = e.getX();
oy = e.getY();
}
});
}
}
Graphics g; int x, y, ox, oy; public myFrame(String title) {
super(title);
setSize(200, 200);
g = getGraphics();//这里为什么获得不到
g.setColor(Color.red); addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
g.drawLine(ox, oy, x, y);
ox = x;
oy = y;
}
}); addMouseMotionListener(new MouseMotionAdapter() {
public void mousePressed(MouseEvent e) {
ox = e.getX();
oy = e.getY();
}
});
}
}
Graphics g; int x, y, ox, oy; public myFrame(String title) {
super(title);
setSize(200, 200);
setVisible(true);//加上这句
g = getGraphics();
g.setColor(Color.red); addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
g.drawLine(ox, oy, x, y);
ox = x;
oy = y;
}
}); addMouseMotionListener(new MouseMotionAdapter() {
public void mousePressed(MouseEvent e) {
ox = e.getX();
oy = e.getY();
}
});
}
}没有测试,楼主试一下吧^o^
package com.ddpie.frame;import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;public class myFrame extends Frame {
Graphics g; int x, y, ox, oy; public myFrame(String title) {
super(title);
setSize(200, 200);
setVisible(true);//加上这句
g = getGraphics();
g.setColor(Color.red); addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
g.drawLine(ox, oy, x, y);
ox = x;
oy = y;
}
}); addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
ox = e.getX();
oy = e.getY();
}
});
}
}