判断DialogFragment是否已经显示

http://stackoverflow.com/questions/21352571/android-how-do-i-check-if-dialogfragment-is-showing

android: how do I check if dialogfragment is showing

if(dialogFragment!=null &&  dialogFragment.getDialog()!=null
   && dialogFragment.getDialog().isShowing()) {
   //dialog is showing so do something 
} else {
   //dialog is not showing
}