Android basics

First thing to do before starting making your android program is plan. here things you need to know before you start coding anything:

What your program is. Is it calculator or game or what?

what functionality it needs. does it play sound, does it need acceleration or fancy graphics

how to divide it in functional different classes and does it use patterns. Notice MVC pattern is good for games

decide does it need many Activities or views and if so how they communicate and are related

now calculated time needed and multiply whit pi. if it takes too much reduce functionality.

find core functionality and bare basic that are needed and implement them

if time was let from previous one, implement all rest fancy stuff you planed originaly

Layouts

When building Gui it is important to choose right layout. while using linear layouts is easy they are very restrictive. Relative in other hand is way to get complicated designs but need often small changes to xml. I suggest to use Realative Layout as default. Things that you find your self adding by hand to xml are.

android:layout_centerHorizontal=“true”

android:layout_centerVertical=“true”

to get element centered

android:onClick=“onSaveButtonClick”

to add click listening to buttons,togglebuttos and pretty much everything

links:

http://developer.android.com/guide/topics/ui/declaring-layout.html

http://www.learn-android.com/2010/01/05/android-layout-tutorial/

Icons and resources

your android project has resources in res folder. you can add resources by manually editing files in case of res/values/strings that is rather suitable and easy

Links:

http://developer.android.com/guide/topics/resources/available-resources.html#layoutresources

AndroidManifest.xml

often manifest file is missing your brand new Activity or you haven't set permissions there, So keep close eye on this file as it causes you lots of problems if you don't

links:

http://developer.android.com/guide/topics/manifest/manifest-intro.html

If your project stops building suddenly

run in eclipse menu project/clean. If that doesn't help check next files that there aren't some trash in them. This can happen whit automatic code generation for older android versions. avoid those automatic generations and code your code other way so you don't need to use them as they will destroy your project some times.

project.properties

proguard-propertise.txt

AndroidManifest.xml

and check resource files