Android : Deal With Multiple Screensizes + Dynamic Controls In Droid?

I am learning how to program on Android phone. However I am unsure how to make my application work for the different screen sizes and resolutions.

I read the tutorial on the android site and still unsure how to do it.

First I know there are different files so could make a layout for each of the sizes but my problem is most of the screen needs to be dynamically created so there would not be much to put in these files.

So I am not sure how to android to re size dynamic controls based on the screen size.

I have also read it is bad practice to make controls in anything but the xml file as it separates view logic and programming logic. However they never talk about if you need to make these controls dynamically what you should do.

So is there some other way to do it that is considered good practice?

Edit

I get this error when I try to run the switcher application.

[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: Error type 2
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: Error: Unable to connect to activity manager; is the system running?
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: usage: am [start|broadcast|instrument|profile]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: am start [-D] INTENT
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: am broadcast INTENT
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: am instrument [-r] [-e <ARG_NAME> <ARG_VALUE>] [-p <PROF_FILE>]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [-w] <COMPONENT>
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: am profile <PROCESS> [start <PROF_FILE>|stop]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: INTENT is described with:
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [-a <ACTION>] [-d <DATA_URI>] [-t <MIME_TYPE>]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [-c <CATEGORY> [-c <CATEGORY>] ...]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [-e|--es <EXTRA_KEY> <EXTRA_STRING_VALUE> ...]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [--ez <EXTRA_KEY> <EXTRA_BOOLEAN_VALUE> ...]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [-e|--ei <EXTRA_KEY> <EXTRA_INT_VALUE> ...]
[2010-04-27 12:06:41 - ViewSwitcherTest] ActivityManager: [-n <COMPONENT>] [-f <FLAGS>] [<URI>]

To your question: It's dynamic because
the buttons in my example grow and
shrink depending on one of the 3
possibles sizes, because they use
scaled pixel (You probably know that
you don't have to deal with screen
sizes itself). So a scaled pixel
compared to a real a pixel has a size
of 0.75px, 1.0px or 1.5px. Android
automatically and dynamically adjusts
it to the actual size. So you don't
have to care about this in your code.

So if I use scaled pixels then I don't have to worry about different screen sizes?

At the moment I don't know an example
except in games where you have to deal
with "real" pixel. But if you want use
it, multiply it with the value of the
current density. This is your "ratio".
I don't have the example with the ball
anymore but I have another which uses
the same technics. You can run it on
different screen sizes and you will
see that the buttons will always fit
into the layout. You could use the
same technics for your intents. In
this example you can scroll with the
"Scrn" buttons from one view to
another of 4 views. (At the moment
they all have a black background so
you don't see that they are different
views). The "Enter" button exits the
test. It's an Eclipse project. You can
download

So if I want to deal with ratio then I use real pixels and not scaled pixels? What advantage does this give me?

will scaled pixels work with changing from portrait to landscape( ie will it fill up the new found space)?

Finally should I make the controls now through code or is there another way? As I said I am getting data from a webservice that must look like this

checkbox label label

It can be one record or 10,000 records I don't know so these have to be appended to something that is like a window panel( the controls in there get a scroll bar).