Android 'Unable to add window -- token null is not for an application' exception

Question

I'm guessing - are you trying to create Dialog with an application context? Something like this:

new Dialog(getApplicationContext());

This is wrong. You need to use an Activity context.

You have to try like:

new Dialog(YourActivity.this);

You can continue to use getApplicationContext(), but before use, you should add this flag: dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT), and the error will not show.

And don't forget to add permission:

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

In my case I was trying to create my dialog like this:

new Dialog(getApplicationContext());

So I had to change for:

new Dialog(this);

And it works fine for me ;)

Try getParent() at the argument place of context like new AlertDialog.Builder(getParent()); Hope it will work, it worked for me.

I'm guessing - are you trying to create Dialog using.

 getApplicationContext()
 mContext which is passed by activity.

if You displaying dialog non activity class then you have to pass activity as a parameter.

Activity activity=YourActivity.this;

Now it will be work great.

If you find any trouble then let me know.

I tried with this in the context field:

this.getActivity().getParent()

and it works fine for me. This was from a class which extends from "Fragment":

public class filtro extends Fragment{...