Java基础-列出指定目录内容和对话框（Dialog）

列出指定目录内容和对话框  演示代码：import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class code
{
public static void main(String[] args) {
new myWindow();
}
}

class myWindow
{
private Frame f;
private TextField tf;
private Button but;
private TextArea ta;

private Dialog d;//对话框
private Label lab;
private Button okbut;

public myWindow() {
init();
}

public void init() {
f = new Frame("my window");
f.setBounds(300,100,600,500);
f.setLayout(new FlowLayout());

tf = new TextField(60);//只有一行可写
but = new Button("转到");
ta = new TextArea(25,70);//是一个区域,可以有很多行

d = new Dialog(f,"提示信息",true);//窗体,true才可操作窗体
d.setBounds(500,300,300,100);
d.setLayout(new FlowLayout());
lab = new Label();//构造空标签
okbut = new Button("确定");

d.add(lab);
d.add(okbut);

f.add(tf);
f.add(but);
f.add(ta);

myEvent();
f.setVisible(true);//显示
}
//处理事件
private void myEvent() {
//确定按钮
okbut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
d.setVisible(false);
}
});

//对话框事件
d.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
d.setVisible(false);
}
});

//判断回车
tf.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
if(e.getKeyCode()==KeyEvent.VK_ENTER)
showDir();
}
});

//打印数据
but.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
showDir();
}
});
//关闭窗口
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}

private void showDir() {
String dirpath = tf.getText();

File dir = new File(dirpath);
if(dir.exists() && dir.isDirectory()) {
ta.setText("");//清空
String[] names = dir.list();
for(String name : names) {
ta.append(name+"\r\n");//显示全部
//ta.setText();//显示一个
}
}
//tf.setText(dirpath);
//System.out.println(text);
//tf.setText("");
else {
String info = "您输入的信息:"+dirpath+"是错误的，请重新输入";
lab.setText(info);
d.setVisible(true);
}
}
}