Need to display Toast right after click

Question

I saw related posts like this - Disable the Asynchronous display of a Toast [duplicate] and I tried cancel() method from there, but they don't solve my problem. Maybe it is because some difference related with Preference Activity.

Please, help me improve my code so the Toast displays right after click.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.pref_screen);
    Context context = getApplicationContext();
    settings = PreferenceManager.getDefaultSharedPreferences(context);
    settings.registerOnSharedPreferenceChangeListener(this);
}

public void onSharedPreferenceChanged(SharedPreferences settings, String key) {
    Toast theToast;
    theToast = Toast.makeText(this, "toast text", Toast.LENGTH_LONG);

    if(key.equals("checkbox_key")){
        theToast.show();
    }
    if (key.equals("checkbox_key")&& theToast != null){
        theToast.cancel();
    }
}

ajpolt · Accepted Answer · 2016-03-21T19:56:28.760

Your question is poorly worded, but I assume (after reading your code) what you're asking is how to cancel a currently displayed Toast when you check/uncheck a new box and want to display a new Toast right away in that case.

The problem is that you're canceling the Toast that you just made, instead of the Toast that is being displayed, which you created earlier.

Try storing the Toast in a member variable and canceling that instead. Something like:

private Toast mCurrerntToast = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    //...
}

public void onSharedPreferenceChanged(SharedPreferences settings, String key) {
    if(key.equals("checkbox_key")){
        //If there is a previous toast displayed, cancel it
        if(mCurrentToast != null){
            mCurrentToast.cancel();
        }

        //Display a new, more current Toast message
        mCurrentToast = Toast.makeText(this, "toast text", Toast.LENGTH_LONG);
        mCurrentToast.show();
    }
}

Let me know if my assumption of what you were asking about was wrong and I'll try to help more, but I'm pretty sure this is the problem you're trying to solve.

You understand me correct. As about you solution. AndroidStudio shows comment that, Variable "mCurrentToast" might not have been initialized. I moved this line `mCurrentToast = Toast.makeText(this, "toast text", Toast.LENGTH_LONG);` before all if statements like in my previous code, but it crashes the app (NullExeption). — Robert, Mar 21 '16 at 19:51
You can't move that line before the ".cancel()" line or else you'll cancel your new Toast instead of the old one. Just set mCurrentToast to null when you create it. I'll update my code example to reflect that. — ajpolt, Mar 21 '16 at 19:54

Need to display Toast right after click

1 Answers1