Basic Android

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Revision as of 21:57, 30 August 2011 by Jeff (talk | contribs) (Android Basics)
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Android Basics

after installing the plugin you may need to change the path to the SDK there is currently a bug if you us a folder with a space in the name use C:\PROGRA~2\Android\android-sdk if you installed to "C:\Program Files (x86)\Android"


  • src folder containg all the source
  • res folder containing all the resources


No DPI or PPI Andoid uses dp density independent pixels or sp scale interdependent pixels

also see supporting multiple screens


Activity life cycle

Get an instance of an object from the R class

<java>/** Called when the activity is first created. */

   public void onCreate(Bundle savedInstanceState) {
       //Get the Button and the TextView from the Resource class
       Button btn = (Button)this.findViewById(;
       final TextView tv = (TextView)this.findViewById(;  
       String s = "hello";


notice the cast to the type also notice that the TextView is marked as final 
this is so that we can use it in an inner method

handle a click event <java> btn.setOnClickListener(new View.OnClickListener() {

@Override public void onClick(View v) { // TODO Auto-generated method stub tv.setText(d.About()); } });</java>


Lots more good reading

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