this 到底怎么用啊!!!救我! this指FileDialog的父窗体。也就是为FileDialog指定一个parent frame 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 你的这个类是一个内部类吗?它存在于一个扩展自Frame类型的类中吗?this在这里必须是Frame类型的 import java.awt.event.*;import java.awt.*;public class FiledialogText extends Frame{ TextField filename = new TextField(); TextField directory = new TextField(); Button open = new Button("Open"); Button save = new Button("Save"); public FiledialogText(){ setTitle("File Dialog Text:"); Panel p = new Panel(); p.setLayout(new FlowLayout()); p.add(open); p.add(save); add("South", p); directory.setEditable(false); filename.setEditable(false); p = new Panel(); p.setLayout(new GridLayout(2,1)); p.add(filename); p.add(directory); add("North", p); open.addActionListener(new B1()); open.addActionListener(new B2()); } class B1 implements ActionListener{ public void actionPerformed(ActionEvent e){ FileDialog d = new FileDialog(this, "what file do you want to open"); d.setFile("*.java"); d.setDirectory("."); d.show(); String openFile; if((openFile = d.getFile()) != null){ filename.setText(openFile); directory.setText(d.getDirectory()); } else{ filename.setText("You pressed cancel"); directory.setText(""); } } } class B2 implements ActionListener{ public void actionPerformed(ActionEvent e){ FileDialog d = new FileDialog(this,"what file do you want to save"); d.setFile("*.java"); d.setDirectory("."); d.show(); String saveFile; if((saveFile = d.getFile())!=null){ filename.setText(saveFile); directory.setText(d.getDirectory()); } else{ filename.setText("You pressed cancel"); directory.setText(""); } } } public static void main(String args[]){ Frame f = new FiledialogText(); f.resize(250,110); f.show(); }} 能帮我看看吗? 这里this需要的类型是Frame需要引用FiledialogText的当前实例 这里this需要的类型是Frame需要引用FiledialogText的当前实例 菜鸟求助:Java 程序解释 java的泛型参数问题 java 进度条,不是弹出的进度条,是在JLabel或者JTextField里面显示一个进度,该怎么做呢 关于用记事本写程序的问题! 请问各位,用JAVA做超市管理系统的流程和所需要用到的东西都是什么? 设置java环境怎么不行啊? 求教:java调用VB的activex dll的问题 ConnectionPool的简单问题 一个小问题 Java中 byte 内部类的作用?? 我用一张图片作为背景,现在又在上面画了一张小的,把小的移移走后,怎么样把原来的地方再用背景图补上呀
它存在于一个扩展自Frame类型的类中吗?
this在这里必须是Frame类型的
import java.awt.*;
public class FiledialogText extends Frame{
TextField filename = new TextField();
TextField directory = new TextField();
Button open = new Button("Open");
Button save = new Button("Save");
public FiledialogText(){
setTitle("File Dialog Text:");
Panel p = new Panel();
p.setLayout(new FlowLayout());
p.add(open);
p.add(save);
add("South", p);
directory.setEditable(false);
filename.setEditable(false);
p = new Panel();
p.setLayout(new GridLayout(2,1));
p.add(filename);
p.add(directory);
add("North", p);
open.addActionListener(new B1());
open.addActionListener(new B2());
}
class B1 implements ActionListener{
public void actionPerformed(ActionEvent e){
FileDialog d = new FileDialog(this, "what file do you want to open");
d.setFile("*.java");
d.setDirectory(".");
d.show();
String openFile;
if((openFile = d.getFile()) != null){
filename.setText(openFile);
directory.setText(d.getDirectory());
}
else{
filename.setText("You pressed cancel");
directory.setText("");
}
}
}
class B2 implements ActionListener{
public void actionPerformed(ActionEvent e){
FileDialog d = new FileDialog(this,"what file do you want to save");
d.setFile("*.java");
d.setDirectory(".");
d.show();
String saveFile;
if((saveFile = d.getFile())!=null){
filename.setText(saveFile);
directory.setText(d.getDirectory());
}
else{
filename.setText("You pressed cancel");
directory.setText("");
}
}
}
public static void main(String args[]){
Frame f = new FiledialogText();
f.resize(250,110);
f.show();
}
}
能帮我看看吗?
需要引用FiledialogText的当前实例
需要引用FiledialogText的当前实例