2
我已經問過這個了，但我需要更多的知識。我正嘗試使用按鈕命令將兩個類連接在一起。我在這裏跟上了最後一個答案，但是當我分開課程時，它不起作用。我用b2Command來觸發事件。這裏是我的代碼：J2ME setCurrent（）
MainMidlet.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.lcdui.StringItem;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Display;
/**
* @author bon
*/
public class MainMidlet extends MIDlet implements CommandListener,
ItemCommandListener, ItemStateListener{
private Display display;
private Form form;
private Command okCommand, backCommand, exitCommand, b1Command, b2Command, exCommand, boutCommand;
private StringItem b1stringItem, b2stringItem, boutstringItem, exstringItem;
public AddCalendarEvent addcalendarevent;
public MainMidlet(){
okCommand = new Command ("OK", Command.OK, 1);
exitCommand = new Command ("EXIT", Command.EXIT, 1);
backCommand = new Command ("BACK", Command.BACK, 1);
b1Command = new Command ("BUTTON", Command.ITEM, 2);
b2Command = new Command ("BUTTON", Command.ITEM, 2);
exCommand = new Command ("BUTTON", Command.ITEM, 2);
boutCommand = new Command ("BUTTON", Command.ITEM, 2);
form = new Form ("CyberMe");
b1stringItem = new StringItem (null, "Make Todo", Item.BUTTON);
b1stringItem.setItemCommandListener (this);
b1stringItem.setDefaultCommand (b1Command);
b2stringItem = new StringItem (null, "Set Alarm", Item.BUTTON);
b2stringItem.setItemCommandListener (this);
b2stringItem.setDefaultCommand (b2Command);
boutstringItem = new StringItem (null, "About", Item.BUTTON);
boutstringItem.setItemCommandListener (this);
boutstringItem.setDefaultCommand (boutCommand);
exstringItem = new StringItem (null, "Exit", Item.BUTTON);
exstringItem.setItemCommandListener (this);
exstringItem.setDefaultCommand (exCommand);
form.append ("Any Appointment?");
form.append (b1stringItem);
form.append (b2stringItem);
form.append (boutstringItem);
form.append (exstringItem);
form.addCommand (okCommand);
form.addCommand (exitCommand);
form.setCommandListener (this);
}
public void startApp() {
display = Display.getDisplay(this);
display.setCurrent(form);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
public void commandAction(Command c, Displayable d) {
throw new UnsupportedOperationException("Not supported yet.");
}
public void commandAction(Command c, Item item) {
if (c == b1Command) {
//display.setCurrent();
}
else if (c == b2Command){
addcalendarevent = new AddCalendarEvent(this);
display.setCurrent(addcalendarevent);
}
else if (c == exCommand){
destroyApp(false);
notifyDestroyed();
}
//else if (c == boutCommand)
//display.setCurrent();
}
public void itemStateChanged(Item item) {
throw new UnsupportedOperationException("Not supported yet.");
}
}
這裏就是我試圖鏈接： AddCalendarEvent.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import javax.microedition.midlet.MIDlet;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.TextField;
import javax.microedition.lcdui.DateField;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.Alert;
import javax.microedition.pim.PIM;
import javax.microedition.pim.PIMItem;
import javax.microedition.pim.EventList;
import javax.microedition.pim.Event;
import javax.microedition.pim.PIMException;
import java.util.Date;
/**
*
* @author bon
*/
public class AddCalendarEvent extends MainMidlet{
private Display display;
// Form where user can enter data of new event.
private Form addEventForm;
// Command for adding event to list of events. Placed on addEventForm.
private Command cmdAddEvent;
// Command for exiting from application. Placed on addEventForm.
private Command cmdExit;
// Text field for summary of event.
private TextField summaryField;
// Date field for start data of event.
private DateField startDateField;
// Date field for end data of event.
private DateField endDateField;
// Text field for note of event.
private TextField noteField;
// Text field for location of event.
private TextField locationField;
/**
* Constructor.
*/
public AddCalendarEvent() {
if(checkPIMSupport() == false) {
exitMIDlet();
}
initializeComponents();
}
/**
* Initializes components of midlet.
*/
public void initializeComponents() {
display = Display.getDisplay(this);
// Create form for adding event.
addEventForm = new Form("Add event");
// Add commands to form and set listener for it.
cmdAddEvent = new Command("Add event", Command.SCREEN, 0);
addEventForm.addCommand(cmdAddEvent);
cmdExit = new Command("Exit", Command.EXIT, 0);
addEventForm.addCommand(cmdExit);
addEventForm.setCommandListener(this);
try {
// Get list of events.
EventList eventList = (EventList)PIM.getInstance().openPIMList(
PIM.EVENT_LIST, PIM.READ_WRITE);
// Create controls based on supported fields for event.
if(eventList.isSupportedField(Event.SUMMARY) == true) {
summaryField = new TextField("Summary", null, 20,
TextField.ANY);
addEventForm.append(summaryField);
} else {
// At least "summary" field must be supported.
// If not, throw exception.
eventList.close();
throw new Exception("Summary field is not supported");
}
if(eventList.isSupportedField(Event.START) == true) {
startDateField = new DateField("Start date",
DateField.DATE_TIME);
startDateField.setDate(new Date());
addEventForm.append(startDateField);
}
if(eventList.isSupportedField(Event.END) == true) {
endDateField = new DateField("End date", DateField.DATE_TIME);
endDateField.setDate(new Date());
addEventForm.append(endDateField);
}
if(eventList.isSupportedField(Event.NOTE) == true) {
noteField = new TextField("Note", null, 20, TextField.ANY);
addEventForm.append(noteField);
}
if(eventList.isSupportedField(Event.LOCATION) == true) {
locationField = new TextField("Location", null, 20,
TextField.ANY);
addEventForm.append(locationField);
}
// Close list of events.
eventList.close();
} catch(PIMException pimExc) {
// TODO: Handle error on working with PIM.
}
catch(SecurityException secExc) {
// TODO: Handle error on access to PIM.
}
catch(Exception exc) {
// If unknown error was catched, exit from application.
exitMIDlet();
}
}
/**
* Checks PIM support.
* @return - true if PIM is supported, false otherwise.
*/
private boolean checkPIMSupport() {
String propValue = System.getProperty("microedition.pim.version");
if(propValue != null) {
return true;
} else {
return false;
}
}
/**
* Adds event to list of events.
* Gets data for event from addEventForm controls.
*/
private void addEvent() {
try {
// Get list of events.
EventList eventList = (EventList)PIM.getInstance().openPIMList(
PIM.EVENT_LIST, PIM.READ_WRITE);
// Create new event.
Event event = eventList.createEvent();
// Get data from controls
if(eventList.isSupportedField(Event.SUMMARY) == true) {
String summary = summaryField.getString();
event.addString(Event.SUMMARY, PIMItem.ATTR_NONE, summary);
} else {
// At least summary must be supported.
eventList.close();
throw new Exception("Summary field for event is not supported");
}
if(eventList.isSupportedField(Event.START) == true) {
long startDate = startDateField.getDate().getTime();
event.addDate(Event.START, PIMItem.ATTR_NONE, startDate);
}
if(eventList.isSupportedField(Event.END) == true) {
long endDate = endDateField.getDate().getTime();
event.addDate(Event.END, PIMItem.ATTR_NONE, endDate);
}
if(eventList.isSupportedField(Event.NOTE) == true) {
String note = noteField.getString();
event.addString(Event.NOTE, PIMItem.ATTR_NONE, note);
}
if(eventList.isSupportedField(Event.LOCATION) == true) {
String location = locationField.getString();
event.addString(Event.LOCATION, PIMItem.ATTR_NONE, location);
}
// Commit event.
event.commit();
// Close list of events.
eventList.close();
// Notify user that event was added
showAlert("Info", "Event was successfully added.");
} catch(PIMException pimExc) {
// TODO: Handle error on working with PIM.
showAlert("PIMException", pimExc.getMessage());
}
catch(SecurityException secExc) {
// TODO: Handle error on access to PIM.
showAlert("SecurityException", secExc.getMessage());
}
catch(Exception exc) {
// TODO: Handle all other errors.
showAlert("Exception", exc.getMessage());
}
}
/**
* Shows alert with specified title and text.
* @param title - Title of alert.
* @param message - text of alert.
*/
private void showAlert(String title, String message) {
Alert alert = new Alert(title);
alert.setString(message);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}
private void exitMIDlet() {
notifyDestroyed();
}
public void commandAction(Command command, Displayable displayable) {
if(command == cmdAddEvent) {
addEvent();
}
if(command == cmdExit) {
exitMIDlet();
}
}
}
嗨！ '返回顯示器上出現紅線錯誤;'它表示非靜態變量顯示。我該怎麼辦？ – drayl
@drayl，我更新了我的答案，請檢查它。 – Lucifer