Android global variable

Question

How can I create global variable keep remain values around the life cycle of the application regardless which activity running.

Answer 1

Use SharedPreferences to store and retrieve global variables.

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
String userid = preferences.getString("userid", null);

Answer 2

Easy!!!!

Those variable you wanna access as global variable, you can declare them as static variables. And now, you can access those variables by using

classname.variablename;

public class MyProperties {
private static MyProperties mInstance= null;

static int someValueIWantToKeep;

protected MyProperties(){}

public static synchronized MyProperties getInstance(){
    if(null == mInstance){
        mInstance = new MyProperties();
    }
    return mInstance;
}

}

MyProperites.someValueIWantToKeep;

Thats It! ;)