Android communication between different Component

Global variable for all the Context in your application:

 

This may solve many problem for you.

the following code from http://stackoverflow.com/questions/708012/android-how-to-declare-global-variables

class MyApp extends Application { private String myState; public String getState(){ return myState; } public void setState(String s){ myState = s; } } class Blah extends Activity { @Override public void onCreate(Bundle b){ ... MyApp appState = ((MyApp)getApplicationContext()); String state = appState.getState(); ... } } <-- AndroidManifest.xml--> <application android:name=".MyApp"// here is the most important android:icon="@drawable/icon" android:label="@string/app_name">

 

Activity to subactivity:

 

1. To send a simple string to subactivity, we can just use Intent.

 

//Code in Main Activity: Intent i = new Intent(MainActivity.this, subactivity.class); i.setAction("String you want to pass"); startActivity(i); //Code in sub Activity: subactivity.this.getIntent().getAction();

 

2.  To send a little complicated structure, we may use Bundle.

//Code in Main Activity: Intent i = new Intent(MainActivity.this, subactivity.class); Bundle b= new Bundle(); b.putString(key,"things you want.")//check the methodes offered by the google, you will know what kind of data you can pass; i.putExtras(b); startActivity(i); //Code in sub Activity: subactivity.this.getIntent().getBundleExtra(key);

 

3. You can define the data you wanna access in every context to be a public static type

class mainActivity extends Activity{ public static Object AccessedbyAll=new .... }