Changing position of the Dialog on screen android

I made a simple AlertDialog in my Activity:

View view = layoutInflater.inflate(R.layout.my_dialog, null);
AlertDialog infoDialog = new AlertDialog.Builder(MyActivity.this)
                    .setView(view)  
                    .create();

infoDialog.show();

With above code, the dialog shows at the (about) the center of the screen.

I am wondering, how can I customize the dialog position to make it showing just under the top Action Bar ? (Is there anyway to change the gravity or something of the dialog?) and how to do it based on my code??