一、SWT简介
Java语言的声望和它在桌面应用程序（GUI程序）所取得的成就显然极不相符，至今仍然很少能看到非常成功Java桌面程序。虽然有JBuilder，Netbean，JProbe等大型软件作为代表，但这仍不能证明Java的GUI程序是成功的：它们的外观总是和同一操作系统平台下的其它软件显得格格不入。对机器配置的需求也似乎永无止境，这使得它们只能被一些总是拥有当前最高性能PC的程序员们所容忍，或是那些不在乎金钱和时间的专业用户所接受。对绝大多数计算机使用者来说，AWT或SWING代表着怪异的界面和无法接受的速度。Standard Widget Toolkit（SWT）或许是Java这一噩梦的终结者，广大Java程序员终于可以开发出高效率的GUI程序，它们拥有标准的外观，几乎没有人能看出你的程序是用Java写出来的，更为重要的是，这些程序是跨平台的。
SWT本身仅仅是Eclipse组织为了开发Eclipse IDE环境所编写的一组底层图形界面 API。或许是无心插柳，或是有意为之，至今为止，SWT无论是在性能和外观上，都超越了SUN公司提供的AWT和SWING。目前Eclipse IDE已经开发到了2.1版本，SWT已经十分稳定。这里指的稳定应该包含两层意思：
一是指性能上的稳定，其中的关键是源于SWT的设计理念。SWT最大化了操作系统的图形构件API，就是说只要操作系统提供了相应图形的构件，那么SWT只是简单应用JNI技术调用它们，只有那些操作系统中不提供的构件，SWT才自己去做一个模拟的实现。可以看出SWT的性能上的稳定大多时候取决于相应操作系统图形构件的稳定性。
另一个稳定是指SWT API包中的类、方法的名称和结构已经少有改变，程序员不用担心由于Eclipse组织开发进度很快（Eclipse IDE每天都会有一个Nightly版本的发布），而导致自己的程序代码变化过大。从一个版本的SWT更新至另一版本，通常只需要简单将SWT包换掉就可以了。
二、Eclipse3.0的SWT编程
1.SWT比AWT和Swing要快多，因为它是利用操作系统的界面组件生成UI的，在java桌面设计领域掀起一场革命
2.环境配置：
windows系统+eclipse3.0
3.具体操作：
(1).新建一java项目，命名SWT,文件结构如下：
+swt
+bin(编译输出)
+src(原文件)
+AddressBookUI.java
+swt-awt-win32-3062.dll(以下均从eclipse\plugins\org.eclipse.swt.win32_3.0.1\os\win32\x86下导入)
+swt-win32-3062.dll
+javaw.exe.manifest
(2).到项目的properties里，在java build path | libraries里将swt.jar导入
(3).AddressBookUI.java原代码如下：
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
public class AddressBookUI {
private Shell shell;
private Text miscText;
private Text addrText;
private Text emailText;
private Text phoneText;
private Text lnameText;
private Text fnameText;
private Button cancelButton;
private Button saveButton;
private Button nextButton;
private Button prevButton;
private Button editButton;
private Button deleteButton;
private Button newButton;
public static void main(String[] args) {
AddressBookUI window = new AddressBookUI();
window.open();
}
public void open() {
final Display display = new Display();
shell = new Shell();
shell.setSize(610, 477);
shell.setText("Address Book");
{
newButton = new Button(shell, SWT.NONE);
newButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
clearText();
setTextEditable(true);
enableEditButtons(false);
enableSaveButtons(true);
System.out.println("New button selected.");
}
});
newButton.setBounds(10, 380, 75, 35);
newButton.setText("New");
}
{
deleteButton = new Button(shell, SWT.NONE);
deleteButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
clearText();
System.out.println("Delete button selected.");
}
});
deleteButton.setBounds(85, 380, 75, 35);
deleteButton.setText("Delete");
}
{
editButton = new Button(shell, SWT.NONE);
editButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
setTextEditable(true);
enableEditButtons(false);
enableSaveButtons(true);
System.out.println("Edit button selected.");
}
});
editButton.setBounds(160, 380, 75, 35);
editButton.setText("Edit");
}
{
prevButton = new Button(shell, SWT.NONE);
prevButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
System.out.println("Previous button selected.");
}
});
prevButton.setBounds(265, 380, 75, 35);
prevButton.setText("Previous");
}
{
nextButton = new Button(shell, SWT.NONE);
nextButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
System.out.println("Next button selected.");
}
});
nextButton.setBounds(340, 380, 75, 35);
nextButton.setText("Next");
}
{
saveButton = new Button(shell, SWT.NONE);
saveButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
setTextEditable(false);
enableEditButtons(true);
enableSaveButtons(false);
System.out.println("Save button selected.");
}
});
saveButton.setBounds(445, 380, 75, 35);
saveButton.setText("Save");
saveButton.setEnabled(false);
}
{
cancelButton = new Button(shell, SWT.NONE);
cancelButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
setTextEditable(false);
enableEditButtons(true);
enableSaveButtons(false);
System.out.println("Cancel button selected.");
}
});
cancelButton.setBounds(520, 380, 75, 35);
cancelButton.setText("Cancel");
cancelButton.setEnabled(false);
}
{
final Group group = new Group(shell, SWT.NONE);
group.setText("Details");
group.setBounds(10, 10, 585, 355);
{
final Label label = new Label(group, SWT.NONE);
label.setBounds(10, 20, 135, 25);
label.setText("First Name:");
}
{
final Label label = new Label(group, SWT.NONE);
label.setBounds(10, 60, 135, 25);
label.setText("Last Name:");
}
{
final Label label = new Label(group, SWT.NONE);
label.setBounds(10, 100, 135, 25);
label.setText("Phone:");
}
{
final Label label = new Label(group, SWT.NONE);
label.setBounds(10, 140, 135, 25);
label.setText("Email:");
}
{
final Label label = new Label(group, SWT.NONE);
label.setBounds(10, 180, 135, 25);
label.setText("Address:");
}
{
final Label label = new Label(group, SWT.NONE);
label.setBounds(10, 255, 135, 25);
label.setText("Miscellaneous Information:");
}
{
fnameText = new Text(group, SWT.BORDER | SWT.READ_ONLY);
fnameText.setBounds(150, 15, 420, 25);
}
{
lnameText = new Text(group, SWT.BORDER | SWT.READ_ONLY);
lnameText.setBounds(150, 55, 420, 25);
}
{
phoneText = new Text(group, SWT.BORDER | SWT.READ_ONLY);
phoneText.setBounds(150, 95, 420, 25);
}
{
emailText = new Text(group, SWT.BORDER | SWT.READ_ONLY);
emailText.setBounds(150, 135, 420, 25);
}
{
addrText = new Text(group, SWT.BORDER | SWT.READ_ONLY | SWT.V_SCROLL);
addrText.setBounds(150, 175, 420, 60);
}
{
miscText = new Text(group, SWT.BORDER | SWT.READ_ONLY | SWT.V_SCROLL);
miscText.setBounds(150, 250, 420, 65);
}
}
setupMenu();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
}
private void setupMenu() {
//create the menu bar
Menu menu = new Menu(shell, SWT.BAR);
shell.setMenuBar(menu);
//add the File option to it
MenuItem file = new MenuItem(menu, SWT.CASCADE);
file.setText("File");
//create a menu for the File option
file.setMenu(new Menu(file));
//add MenuItems to the File menu
MenuItem prevItem = new MenuItem(new Menu(file), SWT.NONE);
prevItem.setText("Previous");
MenuItem nextItem = new MenuItem(new Menu(file), SWT.PUSH);
nextItem.setText("Next");
MenuItem seperator = new MenuItem(new Menu(file), SWT.SEPARATOR);
MenuItem quitItem = new MenuItem(new Menu(file), SWT.PUSH);
quitItem.setText("Quit");
//add listeners for the actions
prevItem.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event e) {
System.out.println("Previous menu item selected.");
}
});
nextItem.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event e) {
System.out.println("Next menu item selected.");
}
});
quitItem.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event e) {
shell.dispose();
}
});
}
private void clearText() {
fnameText.setText("");
lnameText.setText("");
phoneText.setText("");
emailText.setText("");
addrText.setText("");
miscText.setText("");
}
private void setTextEditable(boolean editable) {
fnameText.setEditable(editable);
lnameText.setEditable(editable);
phoneText.setEditable(editable);
emailText.setEditable(editable);
addrText.setEditable(editable);
miscText.setEditable(editable);
}
private void enableEditButtons(boolean enable) {
newButton.setEnabled(enable);
deleteButton.setEnabled(enable);
editButton.setEnabled(enable);
}
private void enableSaveButtons(boolean enable) {
saveButton.setEnabled(enable);
cancelButton.setEnabled(enable);
}
} |
(4).测试运行，run就可以啦 |
