Spinner onItemSelected called erroneously (without

Question

I have a spinner which I am showing in a dialog view, and the moment the dialog starts onItemSelected is called. I don't really want to process this but only when user makes the selection. So I either need to prevent this (maybe because no default value is set?), or I need to know it is not the user that is making this selection?

Answer 1

If you also are shopping for an initially unselected Spinner, you can go with

@Override
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
    if(pos != 0) {
        pos--;

        // your code here
    }
}

Since item 0 is never possible to select. Cheers :-)

Answer 2

Another option in the spirit of Bill Mote's solution is to make the OnItemSelectedListener also an OnTouchListener. The user interaction flag can then be set to true in the onTouch method and reset in onItemSelected() once the selection change has been handled. I prefer this solution because the user interaction flag is handled exclusively for the spinner, and not for other views in the activity that may affect the desired behavior.

In code:

Create your listener for the spinner:

public class SpinnerInteractionListener implements AdapterView.OnItemSelectedListener, View.OnTouchListener {

    boolean userSelect = false;

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        userSelect = true;
        return false;
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        if (userSelect) { 
            // Your selection handling code here
            userSelect = false;
        }
    }

}

Add the listener to the spinner as both an OnItemSelectedListener and an OnTouchListener:

SpinnerInteractionListener listener = new SpinnerInteractionListener();
mSpinnerView.setOnTouchListener(listener);
mSpinnerView.setOnItemSelectedListener(listener);

Answer 3

It worked for me,

private boolean isSpinnerInitial = true;

@Override
public void onItemSelected(AdapterView<?> parent, View view,
        int position, long id) {

    if(isSpinnerInitial)
    {
        isSpinnerInitial = false;
    }
    else  {
        // do your work...
    }

}

Answer 4

I have solved this problem a different way as I noticed sometimes the onItemSelected method was called twice on orientation change or sometimes once.

It seemed to depend on the current spinner selection. So a flag or counter didn't work for me. Instead I record the system time in BOTH onResume() and onCreate using widgetsRestartTime = System.currentTimeMillis()

widgetsRestartTime is declared as a double and as an intance variable.

Now in the onItemSelected() method I check the current time again and subtract widgetsRestartTime from it as follows: if (System.currentTimeMillis() - widgetsRestartTime > 200) { // user triggered event - so this is a real spinner event so process it } else { // system generated event e.g. orientation change, activity startup. so ignore }

Answer 5

You can simply add an int count to solve it :)

 sp.setOnItemSelectedListener(new OnItemSelectedListener() {
    int count=0;
    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
        if(count >= 1){
            int item = sp.getSelectedItemPosition();
            Toast.makeText(getBaseContext(),
                 "You have selected the book: " + androidBooks[item],
                  Toast.LENGTH_SHORT).show();
        }
        count++;
    }


    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
    }
});

Answer 6

If you dont mind using a position for promt you can do something like this every time you want to do staff on the spinner. First set selection to the promt:

spinner.setselected(0);
spinner.add("something");
...

And then do something like that when selection happens:

spinner.ItemSelected += (object sender, AdapterView.ItemSelectedEventArgs e) => 
            {
                if (spinner.SelectedItemPosition != 0)
                {
                   //do staff
                } 
            }