万蕊科技 发表于 2014-4-28 21:54

java Swing 按钮不显示、鼠标滑过才显示

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.ImageObserver;

public class Welcome extends JFrame{
/**
*
*/
private static final long serialVersionUID = 1L;
/**
*
*/
private JButton JB,JB1,JB2,JB3;
private JLabel JL;
private Image img;
private Toolkit tool;

Welcome(){
super("欢迎来到科帮网");
setSize(600,500);
setLocation(250, 150);
Container container = getContentPane();
tool = getToolkit();
container.setLayout(null);

JB = new JButton("查询学校景点信息");
JB1 = new JButton("查询2景点间的最短距离");
JB2 = new JButton("查询旅游路线");
JB3 = new JButton("退出");
JL = new JLabel("欢迎使用校园导游咨询系统");
img = tool.getImage("E://School.jpg");

JB.addActionListener(new MyMonitor());
JB1.addActionListener(new MyMonitor());
JB2.addActionListener(new MyMonitor());
JB3.addActionListener((new MyMonitor()));

JL.setBounds(180, 20, 300, 40);
JB.setBounds(200, 60, 200, 30);
JB1.setBounds(200, 100, 200, 30);
JB2.setBounds(200, 140,200, 30);
JB3.setBounds(500, 400, 90, 30);


container.add(JB);
container.add(JB1);
container.add(JB2);
container.add(JB3);
container.add(JL);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);

}

private class MyMonitor implements ActionListener{

public void actionPerformed(ActionEvent e) {
if(e.getSource()==JB){
new MyGraphy();
setVisible(false);
}
if(e.getSource()==JB1){
new ShowLength();
setVisible(false);
}
if(e.getSource()==JB2){
new ShowView();
setVisible(false);
}

if(e.getSource()==JB3){
System.exit(0);
}

}

}

public void paint(Graphics g){
g.drawImage(img, 100, 230, 400, 250, (ImageObserver) this);

}


public static void main(String[] args) {
new Welcome();
}
}
原因：paint方法被你重写了，但是你没处理好、所以要在 paint 方法前加super.paint(g)

java宫城大师 发表于 2016-3-17 21:53


下来，学习一下。谢谢:victory:

woniu 发表于 2016-4-12 12:18

这个项目太棒勒！下下来学习下！

wudizxt 发表于 2017-8-12 20:43

不错不错不错不错

wudizxt 发表于 2017-8-14 08:31

不错不错不错
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