package test;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.ImageObserver;
import java.text.AttributedCharacterIterator;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JPanel;
import javax.swing.text.html.HTMLDocument.Iterator;
public class TestDrawLine extends JPanel implements MouseMotionListener ,MouseListener
{
public TestDrawLine()
{
}
private List<Point> pointList = new ArrayList<Point>();
@Override
public void mousePressed(MouseEvent e)
{
int x = e.getX();
int y = e.getY();
Point p = new Point();
p.setX(x);
p.setY(y);
pointList.add(p);
System.out.println(x);
System.out.println(y);
}
@Override
public void mouseDragged(MouseEvent e)
{
int x = e.getX();
int y = e.getY();
Point p1 = new Point();
p1.setX(x);
p1.setY(y);
pointList.add(p1);
System.out.println("welcome");
System.out.println("nihao");
}
@Override
public void mouseClicked(MouseEvent e) {
System.out.println("hahaha");
}
@Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
public void mouseExited(MouseEvent e)
{
}
@Override
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mouseReleased(MouseEvent e) {
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
Line2D l2 = new Line2D.Double(50,50,400,400);
g2.draw(l2);
System.out.println("helloworld");
}
}
}
包含主方法的类：
package test;
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JFrame;
public class TestFrame extends JFrame
{
public static void main(String[]args)
{
TestFrame tf = new TestFrame();
TestDrawLine tdl = new TestDrawLine();
tdl.setBackground(Color.WHITE);
tf.setSize(new Dimension(500,500));
tf.add(tdl);
tf.setBackground(Color.WHITE);
tf.setVisible(true);
}
}
运行这个主方法之后，出现了一个frame，上面出现了一条直线，但是我点击面板，却没有输出"welcom"和“你好”在控制台上，只输出了，“helloworld”，请问，问题出在哪里呢？多谢了！
------解决方案--------------------
这是因为你没有加事件监听！
在主方法中加这句：tdl.addMouseListener(tdl);
------解决方案--------------------
public TestDrawLine() {
}
==》
public TestDrawLine() {
addMouseMotionListener(this);
addMouseListener(this);
}