我做了一些作业，我不知道如何开始制作保存和打开按钮。我使用SWT，我的应用程序将读写XML文件。我做的方法，但现在的问题是打开现有的文件和保存现有的文件。如果你能帮我，那就太好了。
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Combo;
import testic.CurrentData;
import testic.ReadWrite;
public class Test {
// These filter names are displayed to the user in the file dialog. Note that
// the inclusion of the actual extension in parentheses is optional, and
// doesn't have any effect on which files are displayed.
private static final String[] FILTER_NAMES = {
"EXtensible Markup Language (*.xml)",
"All Files (*.*)"};
// These filter extensions are used to filter which files are displayed.
private static final String[] FILTER_EXTS = { "*.xml", "*.*"};
protected Shell shell;
private Text text;
private static CurrentData currentData = null;
static ReadWrite test;
/**
* Launch the application.
* @param args
*/
public static void main(String[] args) {
try {
Test window = new Test();
currentData = new CurrentData();
test = new ReadWrite(currentData) ;
test.readXML();
window.open();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Open the window.
*/
public void open() {
Display display = Display.getDefault();
createContents();
shell.open();
shell.layout();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
/**
* Create contents of the window.
*/
protected void createContents() {
shell = new Shell();
shell.setSize(450, 300);
shell.setText("Test App");
//UNIXUSER
Label lblUsername = new Label(shell, SWT.NONE);
lblUsername.setBounds(45, 64, 55, 15);
lblUsername.setText("Username:");
text = new Text(shell, SWT.BORDER);
text.setBounds(179, 61, 91, 21);
text.setText(currentData.getUnixUser());
// DISABLE_TRAFFIC_CHECK
Label lblStatus = new Label(shell, SWT.NONE);
lblStatus.setBounds(45, 111, 118, 15);
lblStatusk.setText("Disable traffic check:");
Button btnCheckButton = new Button(shell, SWT.CHECK);
btnCheckButton.setSelection(currentData.getDisableTrafficCheck());
btnCheckButton.setBounds(212, 110, 93, 16);
// HEALTCHECL_EVERY_TC
Label lblActive = new Label(shell, SWT.NONE);
lblActive.setBounds(45, 156, 129, 15);
lblActive.setText("Health check every TC:");
Menu menu_1 = new Menu(shell); //TODO check if we really need this
shell.setMenu(menu_1);
String[] items = { "None", "True", "False" };
Combo combo = new Combo(shell, SWT.NONE);
combo.setBounds(179, 156, 91, 23);
combo.setItems(items);
String hC = currentData.getHealthCheckEveryTC();
if(hC.equalsIgnoreCase("None")){
combo.select(0);
} else if (hC.equalsIgnoreCase("True")){
combo.select(1);
} else {
combo.select(2);
}
Menu menu = new Menu(shell, SWT.BAR);
shell.setMenuBar(menu);
/** Create file menu*/
MenuItem mntmFile = new MenuItem(menu, SWT.CASCADE);
mntmFile.setText("File");
Menu menu_2 = new Menu(mntmFile);
mntmFile.setMenu(menu_2);
/** New Window*/
MenuItem mntmNew = new MenuItem(menu_2, SWT.NONE);
mntmNew.setText("New");
mntmNew.addSelectionListener(new SelectionAdapter() {
@Override
public void widgetSelected(SelectionEvent e) {
Test windowNew = new Test();
windowNew.open();
}
});
/**Open window*/
final Text fileName = new Text(shell, SWT.BORDER);
GridData data = new GridData(GridData.FILL_HORIZONTAL);
data.horizontalSpan = 4;
fileName.setLayoutData(data);
MenuItem mntmOpen = new MenuItem(menu_2, SWT.NONE);
mntmOpen.setText("Open");
mntmOpen.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
// User has selected to open a single file
FileDialog dlg = new FileDialog(shell, SWT.OPEN);
dlg.setFilterNames(FILTER_NAMES);
dlg.setFilterExtensions(FILTER_EXTS);
String fn = dlg.open();
if (fn != null) {
fileName.setText(fn);
}
}
});
MenuItem mntmSave = new MenuItem(menu_2, SWT.NONE);
mntmSave.setText("Save");
MenuItem mntmSaveAs = new MenuItem(menu_2, SWT.NONE);
mntmSaveAs.setText("Save As");
mntmSaveAs.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
// User has selected to save a file
test.createXML();
FileDialog dlg = new FileDialog(shell, SWT.SAVE);
dlg.setFilterNames(FILTER_NAMES);
dlg.setFilterExtensions(FILTER_EXTS);
dlg.setFilterPath("c:\"); // Windows path
String fn = dlg.open();
if (fn != null) {
fileName.setText(fn);
}
}
});
MenuItem mntmExit = new MenuItem(menu_2, SWT.NONE);
mntmExit.addSelectionListener(new SelectionAdapter() {
@Override
public void widgetSelected(SelectionEvent e) {
MessageBox messageBox = new MessageBox(shell, SWT.ICON_QUESTION
| SWT.YES | SWT.NO);
messageBox.setMessage("Do you really want to exit?");
messageBox.setText("Exiting Application");
int response = messageBox.open();
if (response == SWT.YES)
System.exit(0);
}
});
mntmExit.setText("Exit");
}
protected static void event(String string, Object object) {
// TODO Auto-generated method stub
}
}
FileDialog的open方法返回(第一个)选定文件的绝对路径，如果对话框被取消，则返回null的绝对路径。你应该读/写这个文件。例子:
FileDialog dlg = ...
String filename = dlg.open();
if (filename != null) {
File file = new File(filename);
readXML(file);
}
也许这个SWT片段是有帮助的?