出现此问题是由于dialog.show()之前调用了dialog.setContentView()或者dialog.getwindow()等，正确的应该是dialog.show()之后调用dialog.setContentView()或者dialog.getwindow()
（七十四）Android showDialog时报错requestFeature() must be called before adding content
原文：http://www.cnblogs.com/fuyanan/p/4701675.html