Android2.3 System custom Popupwindow in instantiation times null pointer exception

Situation: Is this, the previous time to do a custom Popupwindow, is to write a class, and then inherit Popupwindow, nothing else, but at the time of instantiation, in the 2.3 system directly to the null pointer exception (4.0 and above the system running is good. ）。

Workaround:

1. If your custom class is an argument-free constructor, you need to write it in the constructor: Super ();

For example:

　　

 Public Mypopupwindow () {        Super();    }

2. If you have a custom class with a constructor with parameters, for example: The parameter is context context. Then you must write in the constructor: Super (context);

For example:

　　

 Public Mypopupwindow (Context context) {        Super(context);    }