I want to know how to go from one screen to another by clicking a button that I have added to a MainScreen. I mean just like we do in the Android onClick event for a button - start another startActivity.
In the event handler for the button click, just "push" the screen that you want to appear next, and it will be pushed to the top of the screen stack. For example:
UiApplication.getUiApplication().pushScreen(nextScreen);
This will be better, using FieldChangeListener
button.setChangeListener(new FieldChangeListener()
{
public void fieldChanged(Field field, int context)
{
UiApplication.getUiApplication().pushScreen(new NextScreen());
}
});
This is the alternative way than using,
UiApplication.getUiApplication.involeLater()
{};
Related
In my blackberry application i make one popup screen which is popup on click of menu item. on that popup screen i took one button. Now i want to show alert dialog box on click of that button.How to do this ?Plz tell me.
You can do like this.
public void fieldChanged(Field field, int context)
{
if(field.equals(your button object))
{
Dialog.alert("Your message");
}
}
I am working with a BlackBerry application for OS 5.0 and later. The application has one screen which displays at the top of screen a Next and a Previous button. and list field also display in this screen at bottom of these both button
When i click on NEXT Button and Previous Button my List will be updated display data..
When i click on NEXT/PREVIOUS Button i have to display small VerticalfieldManager at the center of the screen with Label "Please wait ..." so after design this screen how can we add more field manager in over the another manager ?
Is there any way to display that Field at the application MainScreen like iPhone AppDelegate screen?
btnState.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context)
{ vfm_Middle.add(lblPleasewait);
popup = new PopupScreen(manager);
Thread thread = new Thread()
{
public void run()
{
try
{
Updatelistfield();
stop();
}
catch (InterruptedException e)
{
e.printStackTrace();
}
super.run();
}
public synchronized void stop()
{
// TODO Auto-generated method stub
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run()
{
// TODO Auto-generated method stub
//popup.delete(vfm_Main);
//popup.deleteAll();
//vfm_Main.delete(lblPleasewait);
//lblPleasewait.setText(null);
}
});
}
};
thread.start();
}
});
The proper way of doing that is with a blocking dialog. In BB API this can be done as follows:
VerticalFieldManager manager = new VerticalFieldManager();
manager.add(new LabelField("Please Wait..."));
Screen popup = new PopupScreen(manager);
//Show the pop-up the same way you push a regular screen
This has the advantage of blocking the GUI: if the user pushes the menu or esc key it doesn't have any effect.
If you want to do it in your screen without dialogs, then you can add an empty VerticalFieldManager which you can fill with a label when the message has to be shown. This way, instead of updating the entire screen, only the Manager is refreshed. But then you should write the logic to not letting the user push any button or menu key (or ignoring key press).
I started writing a bb app with a menu.
My problem is I don't know how to react if the selected item is clicked. The menu contains some fields in a VerticalFieldManager that is added in a class that extends MainScreen.
I'm sorry for asking such basic stuff, but i googled 1.5 hours now and didnt find a solution or example, Its my very first blackberry app.
Here you go.
This snippet of code defines a new menu item, with a constructor where you specify the label of the menu item and its position on the menu, and a run method which is called when the user clicks on your menu item.
The run method is called on the UI (event) thread, so you are free to update your user interface components from here, or do whatever else you need to do.
I also included a snippet of a screen class that adds the menu item to its menu.
final class MyMenuItem extends MenuItem
{
MyMenuItem()
{
super("Menu item text", 100000, 0);
}
public void run()
{
// The user has clicked on the menu item, and
// this method was called. Do what you need to do.
}
}
final class MyScreen extends MainScreen
{
// ...
protected void makeMenu ( Menu menu, int instance )
{
// let the system build a default menu first
super.makeMenu(menu, instance);
// add your menu item to the screen
menu.add ( new MyMenuItem() );
}
// ...
}
I have requirement for having onscreen navigation buttons along with menu items on blackberry. I need to generate menu item commands as onscreen buttons. Is there a way to generate onscreen menu item buttons in Blackberry? i.e On each screen of my application the menu items should be populated as onscreen buttons both having same functionality?
Thank you
The easiest way to accomplish what you're trying to do is write one function then have both the button and the menu item use the same function.
For example:
function doSomething() {
// Your Code Here
}
// In the function building your screen
MenuItem somethingMi = new MenuItem() {
private MenuItem() { super("Do Something",100001, 5); }
public void run() { doSomething() };
}
Button somethingBtn = new ButtonField("Do Something");
somethingBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context){
doSomething();
}
}
addMenuItem(somethingMI);
add(somethingBtn);
I am using NullField() in one of my screen so that the default focus should not be on any of the button . but when i am clicking on the screen where no field is there , menu screen is being displayed. i dont want that menu screen to be poped up tough it should open when i click menu button.
Thanks alot
override method.
protected boolean navigationClick(int status, int time) {
Field focus = UiApplication.getUiApplication().getActiveScreen()
.getLeafFieldWithFocus();
if (focus instanceof NullField) {
return true;
}
return super.navigationClick(status, time);
}
Note:This code is only for giving you hint.