如何在j2me中從右向左設置組件方向？

Question

我只需要知道如何在j2me中從右向左設置組件方向。例如，寫作在某些語言中是從右到左開始的。什麼是問

Answer 1

可以使用LAYOUT_RIGHT選項，嘗試運行下面的代碼，

/* 
* 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 root 
*/ 
public class HelloMIDlet extends MIDlet implements CommandListener { 

    private boolean midletPaused = false; 

    //<editor-fold defaultstate="collapsed" desc=" Generated Fields "> 
    private Command exitCommand; 
    private Form form; 
    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[] { getStringItem() }); 
      form.addCommand(getExitCommand()); 
      form.setCommandListener(this); 
      // write post-init user code here 
     } 
     return form; 
    } 
    //</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("Hello", "Hello, World!"); 
      stringItem.setLayout(ImageItem.LAYOUT_RIGHT); 
      // write post-init user code here 
     } 
     return stringItem; 
    } 
    //</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) { 
    } 

}