Question

我使用了静态列表并检查了所选的值，这是正确的。现在将相同的代码应用于从SQLite db动态填充的列表中，显示所单击的值的垃圾值。这是代码

class mal2eng extends MainScreen
                            implements ListFieldCallback {


    private ListField _listfield;


    private Item _selected = null; 



    private Vector _listVector = new Vector();



    mal2eng() {

        Database d;
        try
                {
                    URI myURI=URI.create("file:///SDCard/Databases/MyTestDatabase.db");
                    d=DatabaseFactory.open(myURI);
                   Statement st=d.createStatement("SELECT malLetter FROM MalayalamLetter");
                   st.prepare();
                   net.rim.device.api.database.Cursor c=st.getCursor();
                   Row r;

                   while(c.next())
                   {

                    r=c.getRow();
                    String w=r.getString(0);

                    _listVector.addElement(new Item(w));
                   }
                   st.close();
                   d.close();
                   }
                     catch ( Exception e ) 
        {         
            System.out.println( e.getMessage() );
            e.printStackTrace();
        }                      


        this.setTitle("List");


        _listfield = new ListField(_listVector.size());
        _listfield.setCallback(this); 
             FontManager.getInstance().load("DC124.TTF", "MyFont", FontManager.APPLICATION_FONT) ;
        {
             try {
                FontFamily typeface = FontFamily.forName("MyFont");
                Font myFont = typeface.getFont(Font.PLAIN, 25);
                _listfield.setFont(myFont);
                this.add(_listfield);
            } catch (ClassNotFoundException ex) {
                ex.printStackTrace();}

            }



    }

    protected boolean onSavePrompt() {
        return true;
    }

    protected void makeMenu( Menu menu, int instance ) {

    }

    public void drawListRow(ListField list, Graphics g, int index, int y, int w) {
        Item ToDraw = (Item) this.get(list, index);
        int drawColor = Color.BLACK;

        g.setColor(drawColor);
        g.drawText(ToDraw.word, 0, y, 0, w);
    }


    public Object get(ListField list, int index) {

         return _listVector.elementAt(index);
    }

    public int getPreferredWidth(ListField list) {
        return Display.getWidth();
    }

    public int indexOfList(ListField listField, String prefix, int start) {

        return start;
    }

    public boolean navigationClick(int status, int time) {
    Field focus = _listfield.getLeafFieldWithFocus();


    if (focus instanceof ListField) {
        ListField listField = (ListField)focus;
       String w=listField.getCallback().get(listField,listField.getSelectedIndex()).toString();
      UiApplication ui = UiApplication.getUiApplication();
      ui.pushScreen(new ListFieldScreen(w));
    }
    return true;
}
}

Answer 1

当您从数据库获取数据时，您可以执行的一件小事使用像Vector或类似的数据结构。将数据放入您从数据库获取的向量中。覆盖 navigationClick method如下所示...

navigationClickMethod(int, int ){
 //Call getSelectedindex here 

 // And use this to call Element at the selected index of the dataStructure you have 

}

这是从列表中获取所选值的最简单方法...

检索从列表字段中选择的值

1 个答案: