学完GUI写的一个小程序.顺便改一下老毕那视频中的一个小bug... - 黑马程序员技术交流社区

/*
awt 类////类似记事本的小程序
*/
import java.io.*;
import java.awt.*;
import java.awt.event.*;
class Demo002
{
public static void main(String[] args)
{
new app();
}
}
class app_2
{
private Frame f;
private TextArea ta;
private Button dlBut;
private Label dlLabel;
private MenuBar mb;
private Menu m;
private MenuItem closeM,openM,saveM,newM;
private FileDialog openD,saveD;
private File saveF,openF;
app_2()
{
init();
}
private void init()//初始化
{
f = new Frame("优化代码");
ta = new TextArea("",30,70);
//按钮初始化
mb = new MenuBar();
m = new Menu("文件");
newM = new MenuItem("新建");
saveM = new MenuItem("保存");
openM = new MenuItem("打开");
closeM = new MenuItem("关闭");
//对话框初始化
openD = new FileDialog(f,"打开文件");
saveD = new FileDialog(f,"保存文件",FileDialog.SAVE);
//窗体规格设置
f.setBounds(300,300,600,400);
f.setVisible(true);
//按钮添加
mb.add(m);
m.add(newM);
m.add(openM);
m.add(saveM);
m.add(closeM);
//窗体添加组件
f.add(ta);
f.setMenuBar(mb);
//调用监听器
frameListener();
}
//主窗体监听事件
private void frameListener()
{
//点击x退出程序
f.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
closeM.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
//新建菜单
newM.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
saveF = null;
openF = null;
ta.setText("");
}
});
//打开文件对话框读取文件操作
openM.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
openD.setVisible(true);
String dir = openD.getDirectory();
String path = openD.getFile();
if(path!=null && dir!=null )
{
openF = new File(dir,path);
ta.setText("");
BufferedReader buffr = null;
try
{
buffr = new BufferedReader(new FileReader(openF));
String str = null;
while((str=buffr.readLine())!=null)
ta.append(str+"\r\n");
saveF = openF;//这里是打开文件保存到原来路径的设置
}
catch (IOException ex)
{
throw new RuntimeException("读取失败的");
}
finally
{
try
{
if(buffr!=null)
buffr.close();
}
catch (IOException ex)
{
throw new RuntimeException("关闭失败的");
}
}
}
}
});
//保存文件对话框存储文件操作
saveM.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
if(saveF==null)
{
saveD.setVisible(true);
String dir = saveD.getDirectory();
String path = saveD.getFile();
if(path==null || dir==null)
return ;
saveF = new File(dir,path);
}
BufferedWriter buffw = null;
try
{
buffw = new BufferedWriter(new FileWriter(saveF));
String text = ta.getText();
buffw.write(text);
buffw.flush();
}
catch (IOException ex)
{
throw new RuntimeException("关闭失败的");
}
finally
{
try
{
if(buffw!=null)
buffw.close();
}
catch (IOException ex)
{
throw new RuntimeException("关闭失败的");
}
}
}
});
}
}

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