我希望从下到上显示三个列表字段项。我能够显示三个列表字段项，但它们从上到下显示。我已经尝试设置位置，但它无法正常工作。
import java.util.Vector;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.ui.ContextMenu;
import net.rim.device.api.ui.DrawStyle;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Font;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Manager;
import net.rim.device.api.ui.MenuItem;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.component.BitmapField;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ListFieldCallback;
import net.rim.device.api.ui.component.NullField;
import net.rim.device.api.ui.container.FullScreen;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.util.Arrays;
import net.rim.device.api.ui.component.ListField;
/**
* @author Jason Emerick
*/
public class TaskListField extends UiApplication
{
//statics ------------------------------------------------------------------
public static void main(String[] args)
{
TaskListField theApp = new TaskListField();
theApp.enterEventDispatcher();
}
public TaskListField()
{
pushScreen(new TaskList());
}
}
/*class List extends FullScreen {
TaskList tl;
List(){
super();
TaskList tl=new TaskList();
}
}*/
class TaskList extends MainScreen implements ListFieldCallback {
private Vector rows;
private Bitmap p1;
private Bitmap p2;
private Bitmap p3;
String Task;
ListField listnew=new ListField();
public TaskList() {
super();
listnew.setRowHeight(50);
//setEmptyString("Hooray, no tasks here!", DrawStyle.HCENTER);
listnew.setCallback(this);
p1 = Bitmap.getBitmapResource("1.png");
p2 = Bitmap.getBitmapResource("2.png");
p3 = Bitmap.getBitmapResource("3.png");
rows = new Vector();
for (int x = 0; x < 3; x++) {
TableRowManager row = new TableRowManager();
if (x== 0) {
Task="On Air Now";
}
if (x== 1) {
Task="Music Channel";
}
if (x==2) {
Task="News Channel";
}
// SET THE PRIORITY BITMAP FIELD
// if high priority, display p1 bitmap
if (x % 2 == 0) {
row.add(new BitmapField(p1));
}
// if priority is 2, set p2 bitmap
else if (x % 3 == 0) {
row.add(new BitmapField(p2));
}
// if priority is 3, set p3 bitmap
else {
row.add(new BitmapField(p3));
}
// SET THE TASK NAME LABELFIELD
// if overdue, bold/underline
LabelField task = new LabelField(Task,
DrawStyle.ELLIPSIS);
// if due today, bold
if (x % 2 == 0) {
task.setFont(Font.getDefault().derive(
Font.BOLD));
} else {
task.setFont(Font.getDefault().derive(Font.BOLD));
}
row.add(task);
LabelField task1 = new LabelField("Now Playing" + String.valueOf(x),
DrawStyle.ELLIPSIS);
// if due today, bold
/* if (x % 2 == 0) {
task.setFont(Font.getDefault().derive(
Font.BOLD));
} else {
task.setFont(Font.getDefault().derive(Font.BOLD));
}*/
Font myFont = Font.getDefault().derive(Font.PLAIN, 12);
task1.setFont(myFont);
row.add(task1);
// SET THE DUE DATE/TIME
row.add(new LabelField("",
DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
| DrawStyle.RIGHT) {
protected void paint(Graphics graphics) {
graphics.setColor(0x00878787);
super.paint(graphics);
}
});
rows.addElement(row);
}
listnew.setSize(rows.size());
this.add(listnew);
}
// ListFieldCallback Implementation
public void drawListRow(ListField listField, Graphics g, int index, int y,
int width) {
//TaskList list =(TaskListField) listnew;
TableRowManager rowManager = (TableRowManager)rows
.elementAt(index);
rowManager.drawRow(g, 0, y, width, listnew.getRowHeight());
}
private class TableRowManager extends Manager {
public TableRowManager() {
super(0);
}
// Causes the fields within this row manager to be layed out then
// painted.
public void drawRow(Graphics g, int x, int y, int width, int height) {
// Arrange the cell fields within this row manager.
layout(0, 1);
// Place this row manager within its enclosing list.
setPosition(x,y);
// Apply a translating/clipping transformation to the graphics
// context so that this row paints in the right area.
g.pushRegion(getExtent());
// Paint this manager's controlled fields.
subpaint(g);
g.setColor(0x00CACACA);
g.drawLine(0, 0, getPreferredWidth(), 0);
// Restore the graphics context.
g.popContext();
}
// Arrages this manager's controlled fields from left to right within
// the enclosing table's columns.
protected void sublayout(int width, int height) {
// set the size and position of each field.
int fontHeight = Font.getDefault().getHeight();
int preferredWidth = getPreferredWidth();
// start with the Bitmap Field of the priority icon
/* Field field = getField(0);
layoutChild(field, 0, 0);
setPositionChild(field, 150, 300);*/
// set the task name label field
/* field = getField(1);
layoutChild(field, preferredWidth - 16, fontHeight + 1);
setPositionChild(field, 34, 3);
// set the list name label field
field = getField(2);
layoutChild(field, 150, fontHeight + 1);
setPositionChild(field, 34, fontHeight + 6);*/
// set the due time name label field
/* field = getField(3);
layoutChild(field, 150, fontHeight + 1);
setPositionChild(field,4,340);*/
/* layoutChild(listnew, preferredWidth, fontHeight);
setPositionChild(listnew, 3, 396);*/
setExtent(360, 480);
}
// The preferred width of a row is defined by the list renderer.
public int getPreferredWidth() {
return getWidth();
}
// The preferred height of a row is the "row height" as defined in the
// enclosing list.
public int getPreferredHeight() {
return listnew.getRowHeight();
}
}
public Object get(ListField listField, int index) {
// TODO Auto-generated method stub
return null;
}
public int getPreferredWidth(ListField listField) {
// TODO Auto-generated method stub
return 0;
}
public int indexOfList(ListField listField, String prefix, int start) {
// TODO Auto-generated method stub
return 0;
}
}
我需要修复什么才能让它按照我想要的方式工作？
答案 0 :(得分：0)
我猜您想知道如何将焦点更改为列表字段中的第3项
所以答案是：
listnew.setSelectedIndex(2);