第二章 动态创建对话框怎么搞？求详细过程及程序
出现的问题是：
Starting E:\Qt Pragram\chap02\build-Calculator1-Desktop_Qt_5_4_2_MSVC2013_64bit-Debug\debug\Calculator1.exe...
QIODevice::read: device not open
Designer: An error has occurred while reading the UI file at line 1, column 0: Premature end of document.
