Why `setPositiveButton` always return -1 and how to I get the selected index?

Question

I have a dialog to show settings which toggle App autostart on boot.

User click Enable or Disable, then click OK to save.

The code:

public void showShareDialog(final int itId, String title) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle(title);

    String positiveText = getString(android.R.string.ok);
    String negativeText = getString(android.R.string.cancel);
    String[] items;
    int default_i = 0;
    final SharedPreferences sharedPref = getSharedPreferences("quickSettings", MODE_PRIVATE);
    if (itId == AUTOSTART_LI) {
        items = getResources().getStringArray(R.array.toggle);
        final boolean autostart = sharedPref.getBoolean("autostart", false);
        Log.d("hole", "#autostart get:" + autostart);
        if (!autostart) default_i = 1;

    } else return;

    builder.setSingleChoiceItems(items, default_i, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("hole", "single clicked" + which);

                }
            })
            .setPositiveButton(positiveText, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("hole", "positive clicked:" + which);

                    if (itId == AUTOSTART_LI) {

                        int flag;
                        boolean autostart;
                        if (which == 0) {
                            flag = PackageManager.COMPONENT_ENABLED_STATE_ENABLED;
                            autostart = true;
                        } else {
                            flag = PackageManager.COMPONENT_ENABLED_STATE_DISABLED;
                            autostart = false;
                        }
                        ComponentName component = new ComponentName("com.blogspot.diannaoxiaobai.skyshot"
                                , "com.blogspot.diannaoxiaobai.skyshot.MyReceiver");
                        getPackageManager().setComponentEnabledSetting(component, flag, PackageManager.DONT_KILL_APP);

                        //save only if above no crash
                        SharedPreferences.Editor editor = sharedPref.edit();
                        Log.d("hole", "#autostart saved:" + autostart);
                        editor.putBoolean("autostart", autostart);
                        editor.commit();

                    }
                }
            })
            .setNegativeButton(negativeText, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("hole", "negative clicked:" + which);
                }
            });

    AlertDialog dialog = builder.create();
    dialog.show();
}

But only setSingleChoiceItems able get the index, while setPositiveButton's which variable always print -1, logcat e.g.:

05-12 03:14:41.983  5014  5014 D hole    : single clicked0
05-12 03:14:43.066  5014  5014 D hole    : single clicked1
05-12 03:14:43.615  5014  5014 D hole    : positive clicked:-1

The `which` parameter in `DialogInterface.OnClickListener` tells you what was just clicked. `Dialog.BUTTON_POSITIVE` is `-1`. http://stackoverflow.com/q/2494171 — Mike M., May 11 '17 at 19:46
For those who downvote, come on, think before you downvote, here is the only answer in this planet explicitly to STATE global variable is the key to solve "inner class assign"+"final" contradiction in Android dialog `setSingleChoiceItems`. Even the link above, you will not find any `global` keyword. Some other thread might slightly mention global without stated.(Got one thread it mentioned global and local, what ? local ?) — 林果皞, May 12 '17 at 07:48

rafsanahmad007 · Accepted Answer · 2017-05-11T20:03:55.497

Save your radio Button click position in an Int variable .

Then in your setPositiveButton click check values against your String array.

int index;   //declare Globally

builder.setSingleChoiceItems(items, default_i ,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int item)                   {
                            index = item;   //save radio button click position
                    }
                });
builder.setPositiveButton(positiveText,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int item) {
                        if (items[index] == "Enable") {
                            Toast.makeText(YourActivity.this, "Enable clicked.",Toast.LENGTH_SHORT).show();
                        }
                        if (items[index] == "Disable") {
                            Toast.makeText(YourActivity.this, "Disable clicked.",Toast.LENGTH_SHORT).show();
                        }
                    }
                });

But `index` needs to declare as `final` because of inner class, and `final` will make `index = item;` not possible. — 林果皞, May 11 '17 at 19:59
@林果皞 if you declare it global, you don't have to use final keyword — Hanako, Mar 10 '20 at 16:18

Why `setPositiveButton` always return -1 and how to I get the selected index?

1 Answers1