菜鸟求助！......has initializer but incomplete type

[weixin_38073649]

看了一个范例的代码。在我的机子里试了一下，但是出现了......has initializer but incomplete type的错误，还望大家给个解答，谢谢。代码如下#include <QtCore/QCoreApplication>#include <qpushbutton.h>int main(int argc, char *argv[]){QApplication a(argc,argv);QPushButton hello( "Hello world!", 0 );hello.resize( 100, 30 );a.setMainWidget( &hello );hello.show();return a.exec();}错误信息： error: variable `QApplication a' has initializer but incomplete type