How do you pass variables between classes?

[deenybird]

What intents do I use to pass a variable to another class? And also which intent do I use to receive it?
thanks

[ians]

You can create your own custom Intent and attach whatever you want to it. then create a BroadcastListener at the other end to receive it.

Intent i = new Intent("myintent");
i.putExtra("mydata", data);

---------

IntentFilter f = new IntentFilter();
f.addAction("myintent");
BroadcastReceiver r = new BroadcastReceiver() {
public void onReceive(Context c, Intent i) {
//do something
}};
context.registerReceiver(r, f);

[deenybird]

Thanks for the info. Everything seemed to work except this code "context.registerReceiver(r, f);" which had an error. It wants context to be created as a local variable. If I delete it then the broadcast receiver says it isn't being used.

[ians]

context points to a Context object. If you don't see this anywhere it is probably 'this' ... i.e. Activity objects are also Context objects.

[deenybird]

Thanks ians for your response. I really appreciate it. "this" was what I needed to not get an error. I've posted the code to simplify this and was hoping you could let me know what I'm missing. I've included the code for both classes below. In the onItemSelected method I change arg2 to j which represents the selected item in the list view. I know this works because if you select the 4th item in the list it starts the startNewScreen method at the bottom of the first class. I put the intent code in as you wrote. I added the 'j' variable in the putExtra method of the intent and am trying to get the other class to reconize it so I can use it in an if statement in the second class.

public class MainScreen extends Activity {

public String [] array1={"G1", "iPhone", "Android", "apple", "Google"};

ListView listview1;
TextView txtview1;

int i;
public static int j;

@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);

txtview1=(TextView)findViewById(R.id.textview1);

listview1=(ListView)findViewById(R.id.listview1);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, array1);
adapter.setDropDownViewResource(android.R.layout.s imple_list_item_1);
listview1.setAdapter(adapter);

listview1.setOnItemSelectedListener(new OnItemSelectedListener() {

public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
j = arg2;

if (j > 3) {

startNewScreen();
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});


}

public void startNewScreen () {
Intent variablepass = new Intent("myintent");
variablepass.putExtra("mydata", j);
Intent intent = new Intent(MainScreen.this, MainScreen2.class);
startActivity(intent);
}


}

__________________________________________________ _____________________________________________
Public class MainScreen2 extends Activity {

TextView textview2;
public static int k;
public int j;

public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main2);


textview2=(TextView)findViewById(R.id.textview2);
textview2.setText("Hello2");

IntentFilter f = new IntentFilter("myintent");
f.addAction("myintent");
BroadcastReceiver r = new BroadcastReceiver() {

public void onReceive(Context c, Intent variablepass) {

if (j>3) {
textview2.setText("Google");


};
}
};
this.registerReceiver(r,f);

}


}

[ians]

you need to retrieve the data that you put into the intent.

in you onReceive method:

j = variablepass.getIntExtra("mydata")

[deenybird]

Thanks ians. I actually had tried this but had gotten an error "The method getIntExtra(String, int) in the type Intent is not applicable for the arguments (String)" So I changed it to "j = variablepass.getIntExtra("mydata", j); that 'j' at the end was required (or at least a variable is) I tried putting in a different variable but that didn't seem to work.

Thanks again for your attention to this!