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I have many cases that causing a Null Pointer,
how can this happen?
this is some examples,
1. I have an overlapped window, and when the window's closed, i want to clear the text field, but have an null pointer in the Textbox.
public void onClose$winLoginAdmin(Event event){
if (event instanceof ForwardEvent){
event = ((ForwardEvent)event).getOrigin();
}
event.stopPropagation(); //stop event to prevent window be detached
txtUsernameAdmin.setText("");
txtPasswordAdmin.setText("");
String jqCommand = "jq('$winLoginAdmin').fadeOut(1000)";
Clients.evalJavaScript(jqCommand);
}
when i change like this
public void onClose$winLoginAdmin(Event event){
if (event instanceof ForwardEvent){
event = ((ForwardEvent)event).getOrigin();
}
event.stopPropagation(); //stop event to prevent window be detached
try {
txtUsernameAdmin.setText("");
txtPasswordAdmin.setText("");
}catch (Exception e) {
e.printStackTrace();
}
String jqCommand = "jq('$winLoginAdmin').fadeOut(1000)";
Clients.evalJavaScript(jqCommand);
}
2. i have a popup window, and i set the window visible false, and when i click some button, i want the window appear with some label that have a value filled by user.
public void onClick$tbbStart(Event event){
winStart.setVisible(true);
winStart.doPopup();
winStart.setSizable(false);
com.gellaps.entity.User users = (com.gellaps.entity.User) session.getAttribute("User");
lblUser.setValue(users.getFname());
}
did my code is wrong?
Thanks for your times..
Please check the The closable Property from Developer Guide
Hi woodyki
i have tried to change my code as you said before
my previous
txtUsernameAdmin.setText("");
txtPasswordAdmin.setText("");
my new code
Textbox txtUsernameAdmin = (Textbox) winLoginAdmin.getFellow("txtUsernameAdmin");
txtUsernameAdmin.setText("");
Textbox txtPasswordAdmin = (Textbox) winLoginAdmin.getFellow("txtPasswordAdmin");
txtPasswordAdmin.setText("");
and voila, it's pretty works :)
many thanks woodyki, this so brilliant .. :)
gellaps,
the guys from zk have spent a lot of time for creating the GenericForwardComposer.
If you extend your controller from this GenericForwardComposer the autowiring of the zul components are done for you automatically.
So you need only to declare the components with the same id as you declared in the zul and you have full access to it.
public class MyLoginComposer extends GenericForwardComposer {
private Textbox txtUsernameAdmin; // autowired
private Textbox txtPasswordAdmin; // autowired
. . .
public void myMethod() {
txtUsernameAdmin.setText("");
txtPasswordAdmin.setText("");
}
}
@Stephan,
yes, in fact, i always extends my Composers to GenericForwardComposer.
like this
import org.zkoss.zk.ui.event.Event;
import org.zkoss.zk.ui.util.GenericForwardComposer;
public class LoginComposer extends GenericForwardComposer {
protected static final long serialVersionUID = 1L;
private Textbox txtUsernameAdmin;
private Textbox txtPasswordAdmin;
private Window winLoginAdmin;
public void onClose$winLoginAdmin(Event event){
if (event instanceof ForwardEvent){
event = ((ForwardEvent)event).getOrigin();
}
event.stopPropagation(); //stop event to prevent window be detached
txtUsernameAdmin.setText("");
txtPasswordAdmin.setText("");
String jqCommand = "jq('$winLoginAdmin').fadeOut(1000)";
Clients.evalJavaScript(jqCommand);
}
}
and i have a Null pointer error, until i change the code like what woodyki said.
thanks Stephan for your times
This is not a problem about auto-wired feature of the GenericForwardComposer.
The Composer applied by the main Window can get all components ID on the first level only.
Each nested/child Window component is a ID space owner.
All components inside a child/nested ID space are invisible in the parent ID space (Window).
So, it is need to get the component object by the childWindow.getFellow("component ID").
Woody
Asked: 2011-07-25 23:09:27 +0800
Seen: 368 times
Last updated: Jul 29 '11