我想知道，如何在表单中添加按钮？
下面是我的代码
form = new Form("ePolicia Transgressor Accuse");
tb = new TextField("Complaint Id: ", "", 30, TextField.ANY);
form.append(tb);
ticker = new Ticker("Creating Safer City for You");
form.addCommand(submitCommand);
form.addCommand(exitCommand);
form.setCommandListener(this);
form.setTicker(ticker);
display.setCurrent(form);
现在，我想在表单中添加一个按钮，我可以使用它。
注意：我不是在询问退出、提交等软按钮。我想添加我自己的按钮。
我使用 Netbeans 和 Visual Midlet 为您创建了以下演示代码，希望它对您的代码有所帮助，
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package hello;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
/**
* @author
*/
public class HelloMIDlet extends MIDlet implements CommandListener, ItemCommandListener {
private boolean midletPaused = false;
//<editor-fold defaultstate="collapsed" desc=" Generated Fields ">
private Command exitCommand;
private Command okCommand;
private Command exitCommand1;
private Form form;
private StringItem lblUserName;
private TextField txtUserName;
private StringItem lblPassword;
private TextField txtPassword;
private StringItem lblBlankSpace;
private StringItem cmdOK;
private StringItem stringItem;
//</editor-fold>
/**
* The HelloMIDlet constructor.
*/
public HelloMIDlet() {
}
//<editor-fold defaultstate="collapsed" desc=" Generated Methods ">
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Method: initialize ">
/**
* Initilizes the application.
* It is called only once when the MIDlet is started. The method is called before the <code>startMIDlet</code> method.
*/
private void initialize() {
// write pre-initialize user code here
// write post-initialize user code here
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Method: startMIDlet ">
/**
* Performs an action assigned to the Mobile Device - MIDlet Started point.
*/
public void startMIDlet() {
// write pre-action user code here
switchDisplayable(null, getForm());
// write post-action user code here
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Method: resumeMIDlet ">
/**
* Performs an action assigned to the Mobile Device - MIDlet Resumed point.
*/
public void resumeMIDlet() {
// write pre-action user code here
// write post-action user code here
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Method: switchDisplayable ">
/**
* Switches a current displayable in a display. The <code>display</code> instance is taken from <code>getDisplay</code> method. This method is used by all actions in the design for switching displayable.
* @param alert the Alert which is temporarily set to the display; if <code>null</code>, then <code>nextDisplayable</code> is set immediately
* @param nextDisplayable the Displayable to be set
*/
public void switchDisplayable(Alert alert, Displayable nextDisplayable) {
// write pre-switch user code here
Display display = getDisplay();
if (alert == null) {
display.setCurrent(nextDisplayable);
} else {
display.setCurrent(alert, nextDisplayable);
}
// write post-switch user code here
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Displayables ">
/**
* Called by a system to indicated that a command has been invoked on a particular displayable.
* @param command the Command that was invoked
* @param displayable the Displayable where the command was invoked
*/
public void commandAction(Command command, Displayable displayable) {
// write pre-action user code here
if (displayable == form) {
if (command == exitCommand) {
// write pre-action user code here
exitMIDlet();
// write post-action user code here
}
}
// write post-action user code here
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: exitCommand ">
/**
* Returns an initiliazed instance of exitCommand component.
* @return the initialized component instance
*/
public Command getExitCommand() {
if (exitCommand == null) {
// write pre-init user code here
exitCommand = new Command("Exit", Command.EXIT, 0);
// write post-init user code here
}
return exitCommand;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: form ">
/**
* Returns an initiliazed instance of form component.
* @return the initialized component instance
*/
public Form getForm() {
if (form == null) {
// write pre-init user code here
form = new Form("Welcome", new Item[] { getLblUserName(), getTxtUserName(), getLblPassword(), getTxtPassword(), getLblBlankSpace(), getCmdOK(), getStringItem() });
form.addCommand(getExitCommand());
form.setCommandListener(this);
// write post-init user code here
}
return form;
}
//</editor-fold>
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: lblUserName ">
/**
* Returns an initiliazed instance of lblUserName component.
* @return the initialized component instance
*/
public StringItem getLblUserName() {
if (lblUserName == null) {
// write pre-init user code here
lblUserName = new StringItem("User Name :", "");
lblUserName.setLayout(ImageItem.LAYOUT_CENTER);
// write post-init user code here
}
return lblUserName;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: txtUserName ">
/**
* Returns an initiliazed instance of txtUserName component.
* @return the initialized component instance
*/
public TextField getTxtUserName() {
if (txtUserName == null) {
// write pre-init user code here
txtUserName = new TextField("", "", 32, TextField.ANY);
txtUserName.setLayout(ImageItem.LAYOUT_CENTER | ImageItem.LAYOUT_NEWLINE_AFTER);
// write post-init user code here
}
return txtUserName;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: lblPassword ">
/**
* Returns an initiliazed instance of lblPassword component.
* @return the initialized component instance
*/
public StringItem getLblPassword() {
if (lblPassword == null) {
// write pre-init user code here
lblPassword = new StringItem("Password :", "");
lblPassword.setLayout(ImageItem.LAYOUT_CENTER | ImageItem.LAYOUT_NEWLINE_AFTER);
// write post-init user code here
}
return lblPassword;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: txtPassword ">
/**
* Returns an initiliazed instance of txtPassword component.
* @return the initialized component instance
*/
public TextField getTxtPassword() {
if (txtPassword == null) {
// write pre-init user code here
txtPassword = new TextField("", "", 32, TextField.ANY);
txtPassword.setLayout(ImageItem.LAYOUT_CENTER | ImageItem.LAYOUT_NEWLINE_AFTER);
// write post-init user code here
}
return txtPassword;
}
//</editor-fold>
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: lblBlankSpace ">
/**
* Returns an initiliazed instance of lblBlankSpace component.
* @return the initialized component instance
*/
public StringItem getLblBlankSpace() {
if (lblBlankSpace == null) {
// write pre-init user code here
lblBlankSpace = new StringItem("", "");
// write post-init user code here
}
return lblBlankSpace;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Items ">
/**
* Called by a system to indicated that a command has been invoked on a particular item.
* @param command the Command that was invoked
* @param displayable the Item where the command was invoked
*/
public void commandAction(Command command, Item item) {
// write pre-action user code here
if (item == cmdOK) {
if (command == okCommand) {
// write pre-action user code here
// write post-action user code here
}
} else if (item == stringItem) {
if (command == exitCommand1) {
// write pre-action user code here
exitMIDlet();
// write post-action user code here
}
}
// write post-action user code here
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: okCommand ">
/**
* Returns an initiliazed instance of okCommand component.
* @return the initialized component instance
*/
public Command getOkCommand() {
if (okCommand == null) {
// write pre-init user code here
okCommand = new Command("Ok", Command.OK, 0);
// write post-init user code here
}
return okCommand;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: cmdOK ">
/**
* Returns an initiliazed instance of cmdOK component.
* @return the initialized component instance
*/
public StringItem getCmdOK() {
if (cmdOK == null) {
// write pre-init user code here
cmdOK = new StringItem("Login", "", Item.BUTTON);
cmdOK.addCommand(getOkCommand());
cmdOK.setItemCommandListener(this);
// write post-init user code here
}
return cmdOK;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: stringItem ">
/**
* Returns an initiliazed instance of stringItem component.
* @return the initialized component instance
*/
public StringItem getStringItem() {
if (stringItem == null) {
// write pre-init user code here
stringItem = new StringItem("Cancel", "", Item.BUTTON);
stringItem.addCommand(getExitCommand1());
stringItem.setItemCommandListener(this);
// write post-init user code here
}
return stringItem;
}
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc=" Generated Getter: exitCommand1 ">
/**
* Returns an initiliazed instance of exitCommand1 component.
* @return the initialized component instance
*/
public Command getExitCommand1() {
if (exitCommand1 == null) {
// write pre-init user code here
exitCommand1 = new Command("Exit", Command.EXIT, 0);
// write post-init user code here
}
return exitCommand1;
}
//</editor-fold>
/**
* Returns a display instance.
* @return the display instance.
*/
public Display getDisplay () {
return Display.getDisplay(this);
}
/**
* Exits MIDlet.
*/
public void exitMIDlet() {
switchDisplayable (null, null);
destroyApp(true);
notifyDestroyed();
}
/**
* Called when MIDlet is started.
* Checks whether the MIDlet have been already started and initialize/starts or resumes the MIDlet.
*/
public void startApp() {
if (midletPaused) {
resumeMIDlet ();
} else {
initialize ();
startMIDlet ();
}
midletPaused = false;
}
/**
* Called when MIDlet is paused.
*/
public void pauseApp() {
midletPaused = true;
}
/**
* Called to signal the MIDlet to terminate.
* @param unconditional if true, then the MIDlet has to be unconditionally terminated and all resources has to be released.
*/
public void destroyApp(boolean unconditional) {
}
}
这是输出
