问题
i have tried this link How to customize a ListField in BlackBerry? to create the ListField with Three lablefields for every list row.but iam not able see the list field items.but i can say that listfield is added.because on navigation click i am able get the selected index of the listfield.please anybody help where iam doing mistake.The code i have tried is...
public class InboxWithOutCheckboxeslistfield extends ListField implements ListFieldCallback {
private Vector rows;
private TableRowManager row ;
private LabelField UserName,Message,Timestamp;
/**
* Creates a new MyScreen object
*/
public InboxWithOutCheckboxeslistfield() {
// TODO Auto-generated constructor stub
super(0, ListField.MULTI_SELECT);
setRowHeight(80);
setCallback(this);
rows = new Vector();
for (int x = 0; x < 10; x++) {
row = new TableRowManager();
UserName = new LabelField("" + String.valueOf(x),
DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
| DrawStyle.LEFT);
UserName.setText("name");
row.add(UserName);
Message = new LabelField("" + String.valueOf(x),
DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
| DrawStyle.RIGHT);
Message.setText("hai");
row.add(Message);
Timestamp = new LabelField("" + String.valueOf(x),
DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
| DrawStyle.RIGHT);
Timestamp.setText("hai");
row.add(Timestamp);
rows.addElement(row);
}
setSize(rows.size());
}
public void drawListRow(ListField listField, Graphics graphics, int index,
int y, int width) {
// TODO Auto-generated method stub
InboxWithOutCheckboxeslistfield list = (InboxWithOutCheckboxeslistfield) listField;
TableRowManager rowManager = (TableRowManager) list.rows.elementAt(index);
rowManager.drawRow(graphics, 0, y, width, list.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;
}
private class TableRowManager extends Manager {
protected TableRowManager(){super(0);
// TODO Auto-generated constructor stub}
}
public void drawRow(Graphics graphics, int i, int y, int width,
int rowHeight) {
// TODO Auto-generated method stub
// Arrange the cell fields within this row manager.
layout(width, rowHeight);
// Place this row manager within its enclosing list.
setPosition(i, y);
// Apply a translating/clipping transformation to the graphics
// context so that this row paints in the right area.
graphics.pushRegion(getExtent());
// Paint this manager's controlled fields.
subpaint(graphics);
graphics.setColor(0x00CACACA);
graphics.drawLine(0, 0, getPreferredWidth(), 0);
// Restore the graphics context.
graphics.popContext();
}
protected void sublayout(int width, int height) {
// TODO Auto-generated method stub
// set the size and position of each field.
int fontHeight = Font.getDefault().getHeight();
int preferredWidth = getPreferredWidth();
Field field = getField(0);
layoutChild(field, preferredWidth - 16, fontHeight + 1);
setPositionChild(field, 34, 3);
// set the list name label field
field = getField(1);
layoutChild(field, 150, fontHeight + 1);
setPositionChild(field, 34, fontHeight + 6);
// set the due time name label field
field = getField(2);
layoutChild(field, 150, fontHeight + 1);
setPositionChild(field, preferredWidth - 152, fontHeight + 6);
setExtent(getPreferredWidth(), getPreferredHeight());
}
// 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 getHeight();
}
}
protected boolean navigationClick(int status, int time) {
int index1 = getSelectedIndex();
System.out.println("The Clikced item is:"+index1);
return true;
}
}
and the mainscreen class is
public class InboxWithOutCheckboxes extends MainScreen{
private InboxWithOutCheckboxeslistfield inboxWithOutCheckboxeslistfield;
public InboxWithOutCheckboxes(){
super();
inboxWithOutCheckboxeslistfield = new InboxWithOutCheckboxeslistfield();
add(inboxWithOutCheckboxeslistfield);
add(new SeparatorField());
}
}
回答1:
Try This code -
Add lists on Main Screen-
InboxWithOutCheckboxeslistfield InboxWithOutCheckboxeslistfield = new InboxWithOutCheckboxeslistfield ();
add(InboxWithOutCheckboxeslistfield );
add(new SeparatorField());
Click event listener of list -
protected boolean navigationClick(int status, int time) {
getValue();
return true;
}
protected void getValue() {
Field f = getFieldWithFocus();
if (f instanceof ListField) {
ListField l = (ListField) f;
final int index = l.getSelectedIndex();
FriendsRequestObject _contactslist = (FriendsRequestObject) FriendsRequest_fields.vector.elementAt(index);
final String _name = _contactslist.getSender_name();
final String _id = _contactslist.getSender_id();
//Dialog.alert(_name);
Application.getApplication().invokeLater(new Runnable() {
public void run() {
Dialog.alert(_name);
}
});
// Dialog.alert("The selected element is: "+Integer.toString(l.getSelectedIndex()));
}
}
import java.util.Vector;
import net.rim.device.api.ui.Color;
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.component.LabelField;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ListFieldCallback;
class InboxWithOutCheckboxeslistfield extends ListField implements ListFieldCallback {
private Vector contacts;
static Vector vector = new Vector();
private int contactslist_size = 0;
private String name_ = "", id_="", status_="";
public InboxWithOutCheckboxeslistfield () {
super(0, ListField.MULTI_SELECT);
setRowHeight(60);
setEmptyString("Empty List", DrawStyle.HCENTER);
setCallback(this);
contacts = new Vector();
vector.addElement(new FriendsRequestObject("1", "hai1", ""));
vector.addElement(new FriendsRequestObject("2", "hai2", ""));
vector.addElement(new FriendsRequestObject("3", "hai3", ""));
vector.addElement(new FriendsRequestObject("4", "hai4", ""));
contactslist_size = vector.size();
for (int x = 0; x < contactslist_size; x++) {
FriendsRequestObject b = (FriendsRequestObject) vector.elementAt(x);
id_ = b.getSender_id().toString();
name_ = b.getSender_name().toString();
status_ = b.getimage().toString();
TableRowManager row = new TableRowManager() {
public void paint(Graphics g) {
g.setBackgroundColor(Color.BLACK);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(Color.BLACK);
g.clear();
super.paint(g);
}
};
LabelField name1 = new LabelField(id_, DrawStyle.ELLIPSIS);
name1.setFont(Font.getDefault().derive(Font.PLAIN));
row.add(name1);
LabelField name = new LabelField(name_, DrawStyle.ELLIPSIS);
name.setFont(Font.getDefault().derive(Font.PLAIN));
row.add(name);
// add to the table
contacts.addElement(row);
}
setSize(contacts.size());
}
// ListFieldCallback Implementation
public void drawListRow(ListField listField, Graphics g, int index, int y, int width) {
InboxWithOutCheckboxeslistfield list = (InboxWithOutCheckboxeslistfield ) listField;
TableRowManager rowManager = (TableRowManager) list.contacts.elementAt(index);
rowManager.drawRow(g, 0, y, width, list.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(width, height);
// 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();
/* positioning of fields in list */
// Status
Field field = getField(0);
layoutChild(field, preferredWidth, 50);
setPositionChild(field, 10, 5);
// Name
field = getField(1);
layoutChild(field, 150, fontHeight + 1);
//setPositionChild(field, 1, 2);
setPositionChild(field, 80, fontHeight );
setExtent(preferredWidth, getPreferredHeight());
}
// The preferred width of a row is defined by the list renderer.
public int getPreferredWidth() {
return Graphics.getScreenWidth();
}
// The preferred height of a row is the "row height" as defined in the
// enclosing list.
public int getPreferredHeight() {
return getRowHeight();
}
}
public Object get(ListField listField, int index) {
return null;
}
public int getPreferredWidth(ListField listField) {
return 0;
}
public int indexOfList(ListField listField, String prefix, int start) {
return 0;
}
}
FriendsRequestObject is given below -
public class FriendsRequestObject {
private String sender_id;
private String sender_name;
private String image;
public FriendsRequestObject(String sender_id, String sender_name, String image){
this.sender_id = sender_id;
this.sender_name =sender_name;
this.image =image;
}
public String getimage() {
return image;
}
public void setimage(String image) {
this.image = image;
}
public String getSender_id() {
return sender_id;
}
public void setSender_id(String sender_id) {
this.sender_id = sender_id;
}
public String getSender_name() {
return sender_name;
}
public void setSender_name(String sender_name) {
this.sender_name = sender_name;
}
}
回答2:
Edit your implementation of TableRowManager. You need to change the getPreferredWidth(), and getPreferredHeight(). getWidth() and getHeight() will return wrong value if the sublayout() method execution doesn't finish earlier.
// The preferred width of a row is defined by the list renderer.
public int getPreferredWidth() {
return Display.getWidth();
}
// The preferred height of a row is the "row height" as defined in the
// enclosing list.
public int getPreferredHeight() {
return getRowHeight();
}
来源：https://stackoverflow.com/questions/10731554/in-listfield-not-able-to-view-the-fields-in-blackberry