program a Qt demo

I assume that your environment is OK to program a Qt.By the way all code is done on Ubuntu.
Step1: program a Qt demo in QtProject folder.

#include <QApplication>
#include <QLabel>
#include <QWidget>

int main(int argc, char *argv[])
{
        QApplication app(argc,argv);
        QLabel hello("<center>Welcome to my first Qt program</center>");
        hello.setWindowTitle("My first Qt program");
        hello.resize(400,400);
        hello.show();
        return app.exec();
}

  

 

  
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To save above code in a file testmain.cpp.
Step2: generate a .pro file which is used to generate a Makefile

~/QtProject$ qmake -project
~/QtProject$ ls
QtProject.pro  testmain.cpp

  

 

  
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Step3: add QT += gui widgets to the end of QtProject.pro file.
Step4: to generate a Makefile file which is used to compile the program.

~/QtProject$ qmake QtProject.pro
kyunban@kyunban:~/QtProject$ ls
Makefile  QtProject.pro  testmain.cpp

  

 

  
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Step5: compile this program

~/QtProject$ make
~/QtProject$ ls
Makefile  QtProject  QtProject.pro  testmain.cpp  testmain.o

  

 

  
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Finally, we get a executable file QtProject,run it with below command:

~/QtProject$ ./QtProject

  

 

  
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文章来源: blog.csdn.net，作者：WongKyunban，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/weixin_40763897/article/details/121724519