Java GUI (Instance project-Notepad)

Package mymenu;
Java Notepad
Import java.awt.*;
Import java.awt.event.*;
Import java.io.*;
public class Menulianxi {
Defining forms
Private Frame F;
Defining the menu bar
Private MenuBar MenuBar;
Define text Area
Private TextArea TextArea;
Defining menus
Private Menu File_menu;
Defining menu Items
Private MenuItem Close_item,open_item,save_item;


Define Display dialog box
Private FileDialog Opendia,savedia;

Defines a file that is used to save
private file file;
Defining constructors
Menulianxi () {
Add the init () method to the constructor.
Init ();
}
Defines the method that sets the interface of the UI.
public void Init ()
{
Set up basic information for a form
F=new Frame ("My Notepad");
F.setbounds (300,100,650,600);
F.setlayout (New FlowLayout ());

Initializing the menu bar
Menubar=new menubar ();

Initialize text area
Textarea=new textarea ();

Initialize Menu
File_menu=new Menu ("file");

Initializing menu items
Open_item=new MenuItem ("open");
Close_item=new MenuItem ("exit");
Save_item=new MenuItem ("Save");

Add a menu item or submenu to a menu
File_menu.add (Open_item);
File_menu.add (Save_item);
File_menu.add (Close_item);

Add a menu to the menu bar
Menubar.add (File_menu);

Add a menu bar to a form
F.setmenubar (menubar);

Initialize dialog box
Opendia=new FileDialog (F, "My Open", filedialog.load);
Savedia=new FileDialog (F, "My Save", Filedialog.save);

Add a text area to a form
F.add (textarea);

Add Listener
MyEvent ();

Set form visible
F.setvisible (TRUE);

}
Defining the MyEvent method to add listeners
public void MyEvent ()
{

To add an active listener for a Save menu item
Save_item.addactionlistener (new ActionListener () {
Replication Actionperformed method
public void actionperformed (ActionEvent e)
{
If the file does not exist, initialize it to the file
if (file==null)
{
The Settings window is visible
Savedia.setvisible (TRUE);
Gets the file directory, with the file
String dirpath=savedia.getdirectory ();
String Filename=savedia.getfile ();
Do not manipulate any files, cancel operation
if (dirpath==null| | Filename==null)
return;
File =new file (dirpath,filename);
}

try{
Defines a write stream that writes text to a file
BufferedWriter bufw=new BufferedWriter (new FileWriter (file));
Defines the text where the string receives the text.
String Text=textarea.gettext ();
Write text to the text information.
Bufw.write (text);
Closes the write stream.
Bufw.close ();
}
catch (IOException E4)
{
throw new RuntimeException ();
}
}
});
To add an active listener to an open menu item
Open_item.addactionlistener (new ActionListener () {
public void actionperformed (ActionEvent e)
{
Opendia.setvisible (TRUE);
Get Directory in dialog box
String dirpath=opendia.getdirectory ();
Get the file name in the dialog box
String Filename=opendia.getfile ();
System.out.println (dirpath+ "--" +filename);
Avoid NULL pointer exceptions
if (dirpath==null| | Filename==null)
return;
Clear Text Area
Textarea.settext ("");
Defining file and File directory objects
File=new File (dirpath,filename);
try{
Call BufferedReader Read Stream read file
BufferedReader bufr=new BufferedReader (new FileReader (file));
String Line=null;
Gets the text information in the BUFR
while ((Line=bufr.readline ())!=null)
{
Adds text information to the text area.
Textarea.append (line+ "\ r \ n");
}
Closes the read stream.
Bufr.close ();
}
catch (IOException E1)
{
throw new RuntimeException ("read failed");
}
}
});
Add an activity listener for the menu item Closeitem
Close_item.addactionlistener (new ActionListener () {
@Override
The Actionperformed abstract method adds a processing action.
public void actionperformed (ActionEvent e) {
TODO auto-generated method stubs
System.exit (0);
}
});
The form calls the Addwindowlistener method, passing an interface Class (Listener adapter) Windowadapter.
F.addwindowlistener (New Windowadapter () {
Replication Windowclosing method.
public void windowclosing (WindowEvent e) {
System.exit (0);
}
});
}
public static void Main (string[] args) {
New Menulianxi ();
}
}

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Java GUI (Instance project-Notepad)