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How to run a C++ code in Qt?

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  • RelaR Rela

    I have one "int main(int argc, char argv[])
    { ..."* function in "O_PS .cpp" file, and one main function in "main.cpp" file. Qt

    jsulmJ Online
    jsulmJ Online
    jsulm
    Lifetime Qt Champion
    wrote on last edited by
    #23

    @Rela You should remove one of them.

    https://forum.qt.io/topic/113070/qt-code-of-conduct

    RelaR 1 Reply Last reply
    0
    • jsulmJ jsulm

      @Rela You should remove one of them.

      RelaR Offline
      RelaR Offline
      Rela
      wrote on last edited by Rela
      #24

      @jsulm
      Could you explain how? The main function of "O_PS .cpp" is my C++ code, do I delete:
      int main(int argc, char *argv[])
      {
      QApplication a(argc, argv);
      MainWindow w;
      w.show();

      return a.exec();
      

      } in "main.cpp" ?

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      • jsulmJ Online
        jsulmJ Online
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #25

        I don't know which of them you have to remove. I don't know your code and I don't know what you want to do. You have to decide which of them is the right one and then just delete the other. You just cannot have more than one entry point (more than one main function) in a C/C++ program.

        https://forum.qt.io/topic/113070/qt-code-of-conduct

        RelaR 1 Reply Last reply
        0
        • jsulmJ jsulm

          I don't know which of them you have to remove. I don't know your code and I don't know what you want to do. You have to decide which of them is the right one and then just delete the other. You just cannot have more than one entry point (more than one main function) in a C/C++ program.

          RelaR Offline
          RelaR Offline
          Rela
          wrote on last edited by
          #26

          @jsulm
          I definitely need my C++ code, because everything to get the results is in the code, but when I create a new project in Qt, the "main.cpp" file is also created. If I right click on it and "Remove File" do I need add this code somewhere?

          I had Qt5.4.1 before, and it gave results in "Application output" previously using “Desktop Qt5.4 MinGW” with the same main functions.

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          • SGaistS Offline
            SGaistS Offline
            SGaist
            Lifetime Qt Champion
            wrote on last edited by
            #27

            If you already have a main function that does everything then no. Just keep this in mind: having your main function in a file not named main.cpp is pretty unusual for an application, not forbidden, just unusual. Beware of maintenance nightmare.

            Interested in AI ? www.idiap.ch
            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

            RelaR 1 Reply Last reply
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            • SGaistS SGaist

              If you already have a main function that does everything then no. Just keep this in mind: having your main function in a file not named main.cpp is pretty unusual for an application, not forbidden, just unusual. Beware of maintenance nightmare.

              RelaR Offline
              RelaR Offline
              Rela
              wrote on last edited by Rela
              #28

              @SGaist

              I created another project file, and added the C++ files, but instead of adding the code .cpp file I copied it in "main.cpp" file. The only change I made was that copied the

              QApplication a(argc, argv);
                  MainWindow w;
                  w.show();
              

              After
              int main(int argc, char *argv[])
              {
              . So, now there is only one main function in "main.cpp".

              After that I added the text file by "Argument", using MinGW 32bit, gives this "Runtime Library" error: MinGW 32bit I read maybe its because MinGW is 32bit and I need to use 64 bit as compiler.
              And used "Desktop Qt5.5.1 MSVC 2013 64 bit" , it gives this error: MSVC 64bit

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              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #29

                Run it through the debugger, you're doing something fishy in your code. Throwing a bad alloc means that you are trying to allocated more memory than it's available. It might pass on 64bit (not the same memory limits) but if it does, it means that you are doing something else that is wrong and makes your application crash.

                Interested in AI ? www.idiap.ch
                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                RelaR 2 Replies Last reply
                0
                • SGaistS SGaist

                  Run it through the debugger, you're doing something fishy in your code. Throwing a bad alloc means that you are trying to allocated more memory than it's available. It might pass on 64bit (not the same memory limits) but if it does, it means that you are doing something else that is wrong and makes your application crash.

                  RelaR Offline
                  RelaR Offline
                  Rela
                  wrote on last edited by
                  #30
                  This post is deleted!
                  1 Reply Last reply
                  0
                  • SGaistS SGaist

                    Run it through the debugger, you're doing something fishy in your code. Throwing a bad alloc means that you are trying to allocated more memory than it's available. It might pass on 64bit (not the same memory limits) but if it does, it means that you are doing something else that is wrong and makes your application crash.

                    RelaR Offline
                    RelaR Offline
                    Rela
                    wrote on last edited by
                    #31

                    @SGaist
                    When I click on MSVC to debug MSVC and "F5", it gives this error: No engine
                    When I use MinGW and "F5", it gives this error: MinGW

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                    • SGaistS Offline
                      SGaistS Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on last edited by
                      #32

                      You need to install the debugger for MSVC

                      Interested in AI ? www.idiap.ch
                      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                      RelaR 1 Reply Last reply
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                      • SGaistS SGaist

                        You need to install the debugger for MSVC

                        RelaR Offline
                        RelaR Offline
                        Rela
                        wrote on last edited by
                        #33

                        @SGaist
                        In "Maintenance Tool.exe" these components were chosen. components Do I need to mark "Windows Runtime" also?
                        In "Build & Run", there is one debugger, if it should be added manually, from which folder I have to select it? Debugger

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                        • SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #34

                          MSVC debugger can only be obtained from Microsoft website, here

                          Interested in AI ? www.idiap.ch
                          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                          RelaR 2 Replies Last reply
                          0
                          • SGaistS SGaist

                            MSVC debugger can only be obtained from Microsoft website, here

                            RelaR Offline
                            RelaR Offline
                            Rela
                            wrote on last edited by
                            #35

                            @SGaist
                            Thanks, should I install SDK or WDK?
                            I did search,but it is said that CDB goes with Visual C++, but there is not download link for CDB.

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                            • SGaistS SGaist

                              MSVC debugger can only be obtained from Microsoft website, here

                              RelaR Offline
                              RelaR Offline
                              Rela
                              wrote on last edited by
                              #36

                              @SGaist
                              I installed Windows SDK and chose all components including "debugging tools for windows". Now, in Tools -> Options -> Build & Run -> Debuggers, I see the two paths for CDB. In "Kit" I chose "Desktop Qt5.5.1 MSVC2013 64bit" and from "Debugger" combo, the CDB.
                              I debug the program with it, and it doesn't give the previous error, but first open the mainwindow.ui and then shows "Debugging starts" in "Application Output" and Compile Output.
                              As I wrote before, instead of adding the (C++code.cpp) file I copied the code in "main.cpp" file to have one main fucntion. The only change I made was that copied the

                              QApplication a(argc, argv);
                                  MainWindow w;
                                  w.show();
                              

                              After
                              int main(int argc, char *argv[])
                              {
                              in my C++ code. How can I see the results (which are some numbers) in mainwindow.ui?

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                              • SGaistS Offline
                                SGaistS Offline
                                SGaist
                                Lifetime Qt Champion
                                wrote on last edited by
                                #37

                                Did you implement anything in MainWindow ?

                                Interested in AI ? www.idiap.ch
                                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                RelaR 1 Reply Last reply
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                                • SGaistS SGaist

                                  Did you implement anything in MainWindow ?

                                  RelaR Offline
                                  RelaR Offline
                                  Rela
                                  wrote on last edited by Rela
                                  #38

                                  @Rela
                                  Yes, its an algorithm here written in C++.

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                                  • SGaistS Offline
                                    SGaistS Offline
                                    SGaist
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #39

                                    I can't really read it because of all the whited out parts. But the first thing I'd do is check that you don't do anything funky in there. Remove what's not related to your algorithm from main and try to run that. Once it's good, bring back the Qt parts.

                                    Interested in AI ? www.idiap.ch
                                    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                    RelaR 1 Reply Last reply
                                    0
                                    • SGaistS SGaist

                                      I can't really read it because of all the whited out parts. But the first thing I'd do is check that you don't do anything funky in there. Remove what's not related to your algorithm from main and try to run that. Once it's good, bring back the Qt parts.

                                      RelaR Offline
                                      RelaR Offline
                                      Rela
                                      wrote on last edited by Rela
                                      #40

                                      @SGaist
                                      Sorry for white space, I have to remove some function names. The algorithm is 2820 lines, and I think each line is needed to output the result. Do you mean i remove the algorithm completely and just remain
                                      #include "mainwindow.h"
                                      #include <QApplication>
                                      int main(int argc, char *argv[])
                                      {
                                      QApplication a(argc, argv);
                                      MainWindow w;
                                      w.show();
                                      return a.exec();}

                                      in main.cpp
                                      I did that and the here is the output.

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                                      • SGaistS Offline
                                        SGaistS Offline
                                        SGaist
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #41

                                        Looks like there's no error there. But I meant the other way around. Run just your algorithm code. The error is there somewhere. And you should put a break point at the start so you can go step by step until it breaks.

                                        Interested in AI ? www.idiap.ch
                                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                        RelaR 1 Reply Last reply
                                        0
                                        • SGaistS SGaist

                                          Looks like there's no error there. But I meant the other way around. Run just your algorithm code. The error is there somewhere. And you should put a break point at the start so you can go step by step until it breaks.

                                          RelaR Offline
                                          RelaR Offline
                                          Rela
                                          wrote on last edited by
                                          #42

                                          @SGaist
                                          The algorithm code gives result in MSVC2013.

                                          1 Reply Last reply
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