樹（Tree類）應(yīng)用實(shí)例如下：
1、簡(jiǎn)單樹
?public static void main (String [] args) {
??Display display = new Display ();
??Shell shell = new Shell (display);
??shell.setLayout(new FillLayout());
??
??final Tree tree = new Tree (shell, SWT.BORDER);
??
??for (int i=0; i<4; i++) {
???TreeItem iItem = new TreeItem (tree, 0);
???iItem.setText ("TreeItem (0) -" + i);
???for (int j=0; j<4; j++) {
????TreeItem jItem = new TreeItem (iItem, 0);
????jItem.setText ("TreeItem (1) -" + j);
????for (int k=0; k<4; k++) {
?????TreeItem kItem = new TreeItem (jItem, 0);
?????kItem.setText ("TreeItem (2) -" + k);
?????for (int l=0; l<4; l++) {
??????TreeItem lItem = new TreeItem (kItem, 0);
??????lItem.setText ("TreeItem (3) -" + l);
?????}
????}
???}
??}
??shell.setSize (200, 200);
??shell.open ();
??while (!shell.isDisposed()) {
???if (!display.readAndDispatch ()) display.sleep ();
??}
??display.dispose ();
?}
2、類似資源管理器的樹，其中包含鼠標(biāo)雙擊事件
?public static void main (String [] args) {
??final Display display = new Display ();
??final Shell shell = new Shell (display);
??shell.setText ("Lazy Tree");
??shell.setLayout (new FillLayout ());
??
??final Tree tree = new Tree (shell, SWT.BORDER);
??File [] roots = File.listRoots ();
??for (int i=0; i<roots.length; i++) {
???TreeItem root = new TreeItem (tree, 0);
???root.setText (roots [i].toString ());
???root.setData (roots [i]);//保存當(dāng)前節(jié)點(diǎn)數(shù)據(jù)
???new TreeItem (root, 0);//把當(dāng)前節(jié)點(diǎn)作為目錄節(jié)點(diǎn)
??}
??
??tree.addListener (SWT.Expand, new Listener () {
???public void handleEvent (final Event event) {
????final TreeItem root = (TreeItem) event.item;
????TreeItem [] items = root.getItems ();
????for (int i= 0; i<items.length; i++) {
?????if (items [i].getData () != null) return;
?????items [i].dispose ();
????}
????File file = (File) root.getData ();
????File [] files = file.listFiles ();
????if (files == null) return;
????for (int i= 0; i<files.length; i++) {
?????TreeItem item = new TreeItem (root, 0);
?????item.setText (files [i].getName ());
?????item.setData (files [i]);
?????if (files [i].isDirectory()) {
??????new TreeItem (item, 0);
?????}
????}
???}
??});
????tree.addListener (SWT.MouseDoubleClick, new Listener () {
???public void handleEvent (Event event) {
????Point point = new Point (event.x, event.y);
????TreeItem item = tree.getItem (point);
????if (item != null) {
?????System.out.println ("Mouse down: " + item);
????}
???}
??});
??//根據(jù)Tree的大小更改shell的大小
??Point size = tree.computeSize (300, SWT.DEFAULT);
??int width = Math.max (300, size.x);
??int height = Math.max (300, size.y);
??shell.setSize (shell.computeSize (width, height));
??shell.open ();
??while (!shell.isDisposed ()) {
???if (!display.readAndDispatch ()) display.sleep ();
??}
??display.dispose ();
?}