Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. 3rd Party Software
  4. Error converting string to LPCTSTR with Qt
Forum Updated to NodeBB v4.3 + New Features

Error converting string to LPCTSTR with Qt

Scheduled Pinned Locked Moved Solved 3rd Party Software
winapi
17 Posts 7 Posters 7.4k Views 6 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • C Chris Kawa
    4 Feb 2017, 08:15

    Since you're not using unicode anyway you can also undefine UNICODE and your original code will work.
    Put in your .pro file DEFINES -= UNICODE

    But to be honest your usage of the TEXT macro is wrong anyway (for reasons @Paul-Colby mentioned) so you might just as well stop pretending and use the ANSI types explicitly and don't care for the UNICODE definition:
    LPCSTR _valor = valor.c_str();

    In fact, if you're passing that to some WinAPI function, you don't need to do that at all. You can just directly use the variable, e.g.

    SetWindowTextA(hwnd, valor.c_str());
    //or with UNICODE undefined:
    SetWindowText(hwnd, valor.c_str());
    
    R Offline
    R Offline
    RIVOPICO
    wrote on 4 Feb 2017, 12:17 last edited by RIVOPICO 2 Apr 2017, 12:18
    #7

    @Chris-Kawa Sorry i dont understand very well. You are saying me that i dont need to do the conversion to get to work with my winapi function? But where i willl put this text which variable?

    SetWindowTextA(hwnd, valor.c_str());
    //or with UNICODE undefined:
    SetWindowText(hwnd, valor.c_str());
    
    C 1 Reply Last reply 4 Feb 2017, 14:15
    0
    • R RIVOPICO
      4 Feb 2017, 12:17

      @Chris-Kawa Sorry i dont understand very well. You are saying me that i dont need to do the conversion to get to work with my winapi function? But where i willl put this text which variable?

      SetWindowTextA(hwnd, valor.c_str());
      //or with UNICODE undefined:
      SetWindowText(hwnd, valor.c_str());
      
      C Offline
      C Offline
      Chris Kawa
      Lifetime Qt Champion
      wrote on 4 Feb 2017, 14:15 last edited by
      #8

      @RIVOPICO said in Error converting string to LPCTSTR with Qt:

      But where i willl put this text which variable?

      Now I'm not sure I understand. You put it wherever you want. For example:

      LPCSTR foo = "Hello!";
      SetWindowTextA(hwnd, foo);
      

      or

      LPCWSTR foo = L"Hello!";
      SetWindowTextW(hwnd, foo);
      

      or

      std::string foo = "Hello!";
      SetWindowTextA(hwnd, foo.c_str());
      

      or

      QString foo = "Hello";
      SetWindowTextW(hwnd, (LPCWSTR)foo.utf16());
      
      R 1 Reply Last reply 16 Feb 2017, 21:08
      3
      • C Chris Kawa
        4 Feb 2017, 14:15

        @RIVOPICO said in Error converting string to LPCTSTR with Qt:

        But where i willl put this text which variable?

        Now I'm not sure I understand. You put it wherever you want. For example:

        LPCSTR foo = "Hello!";
        SetWindowTextA(hwnd, foo);
        

        or

        LPCWSTR foo = L"Hello!";
        SetWindowTextW(hwnd, foo);
        

        or

        std::string foo = "Hello!";
        SetWindowTextA(hwnd, foo.c_str());
        

        or

        QString foo = "Hello";
        SetWindowTextW(hwnd, (LPCWSTR)foo.utf16());
        
        R Offline
        R Offline
        RIVOPICO
        wrote on 16 Feb 2017, 21:08 last edited by RIVOPICO
        #9

        @Chris-Kawa But for example if i have this function:

        HRSRC res=FindResource(NULL,L"->SetWindowsTextA?",RT_RCDATA);
        

        How i can use SetWindowText? I must to save the result in my variable?. In other words, how i can apply setwindowstext to save in a var and put in my second argument?

        1 Reply Last reply
        0
        • C Offline
          C Offline
          Chris Kawa
          Lifetime Qt Champion
          wrote on 16 Feb 2017, 21:31 last edited by
          #10
          HRSRC res=FindResource(NULL,L"->SetWindowsTextA?",RT_RCDATA);
          

          That doesn't make any sense whatsoever. SetWindowsText was just an example of WinAPI function since you never said what function you're interested in. Replace it with whatever function you need. If it's FindResource then you can do any of these:

          HRSRC res = FindResourceA(NULL, "SomeResourceName", RT_RCDATA);
          

          or

          HRSRC res = FindResourceW(NULL, L"SomeResourceName", RT_RCDATA);
          

          or

          LPCSTR foo = "SomeResourceName";
          HRSRC res = FindResourceA(NULL, foo, RT_RCDATA);
          

          or

          LPCWSTR foo = L"SomeResourceName";
          HRSRC res = FindResourceW(NULL, foo, RT_RCDATA);
          

          or

          QString foo = "SomeResourceName";
          HRSRC res = FindResourceW(NULL, (LPCWSTR)foo.utf16(), RT_RCDATA);
          

          or any of the dozen other possibilities.

          R 1 Reply Last reply 17 Feb 2017, 12:11
          2
          • C Chris Kawa
            16 Feb 2017, 21:31
            HRSRC res=FindResource(NULL,L"->SetWindowsTextA?",RT_RCDATA);
            

            That doesn't make any sense whatsoever. SetWindowsText was just an example of WinAPI function since you never said what function you're interested in. Replace it with whatever function you need. If it's FindResource then you can do any of these:

            HRSRC res = FindResourceA(NULL, "SomeResourceName", RT_RCDATA);
            

            or

            HRSRC res = FindResourceW(NULL, L"SomeResourceName", RT_RCDATA);
            

            or

            LPCSTR foo = "SomeResourceName";
            HRSRC res = FindResourceA(NULL, foo, RT_RCDATA);
            

            or

            LPCWSTR foo = L"SomeResourceName";
            HRSRC res = FindResourceW(NULL, foo, RT_RCDATA);
            

            or

            QString foo = "SomeResourceName";
            HRSRC res = FindResourceW(NULL, (LPCWSTR)foo.utf16(), RT_RCDATA);
            

            or any of the dozen other possibilities.

            R Offline
            R Offline
            RIVOPICO
            wrote on 17 Feb 2017, 12:11 last edited by RIVOPICO
            #11

            @Chris-Kawa said in Error converting string to LPCTSTR with Qt:

            LPCSTR foo = "SomeResourceName";
            HRSRC res = FindResourceA(NULL, foo, RT_RCDATA);

            When i use in qt findresourceA all time take me error i tried the two ways.
            code:

            HRSRC res = FindResourceA(NULL, "SomeResourceName", RT_RCDATA);
            

            error:

            error: C2664: 'HRSRC FindResourceA(HMODULE,LPCSTR,LPCSTR)' : el argumento 3 no puede convertirse de 'LPWSTR' a 'LPCSTR'
            the types are not related; the conversion require reinterpret_cast, conversi¢n of style of C or conversi¢n of style of function
            

            second way:

            LPCSTR foo = "SomeResourceName";
            HRSRC res = FindResourceA(NULL, foo, RT_RCDATA);
            

            error:

            error: C2664: 'HRSRC FindResourceA(HMODULE,LPCSTR,LPCSTR)' : el argumento 3 no puede convertirse de 'LPWSTR' a 'LPCSTR'
            Los tipos se¤alados no est n relacionados; la conversi¢n requiere reinterpret_cast, conversi¢n de estilo de C o conversi¢n de estilo de funci¢n
            

            i can't use the Ansi version with Qt and i dont know why,

            i tried the ex version but not seems to work too:

            LPCSTR foo = "SomeResourceName";
            WORD myVariable;
            HRSRC res = FindResourceExA(NULL, foo, RT_RCDATA,myVariable);
            

            error:

            error: C2664: 'HRSRC FindResourceExA(HMODULE,LPCSTR,LPCSTR,WORD)' : el argumento 3 no puede convertirse de 'LPWSTR' a 'LPCSTR'
            the types are not related; the conversion require reinterpret_cast, conversi¢n of style of C or conversi¢n of style of function
            
            1 Reply Last reply
            0
            • mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on 17 Feb 2017, 12:22 last edited by
              #12

              Hi
              Dont it complain about param 3 ?

              error: C2664: 'HRSRC FindResourceA(HMODULE,LPCSTR,LPCSTR)' : el argumento 3 no puede convertirse de 'LPWSTR' a 'LPCSTR'

              so it seems its RT_RCDATA that it barf at ?

              1 Reply Last reply
              1
              • R Offline
                R Offline
                RIVOPICO
                wrote on 17 Feb 2017, 12:29 last edited by RIVOPICO
                #13

                lol the strange thing this compile

                LPCWSTR foo = L"ELEXE";
                HRSRC res = FindResourceW(NULL, foo, RT_RCDATA);
                

                But obviously return error 1812.
                i tried ansi versión but i can't use it because return me error with the third argument?

                mrjjM 1 Reply Last reply 17 Feb 2017, 12:32
                0
                • R RIVOPICO
                  17 Feb 2017, 12:29

                  lol the strange thing this compile

                  LPCWSTR foo = L"ELEXE";
                  HRSRC res = FindResourceW(NULL, foo, RT_RCDATA);
                  

                  But obviously return error 1812.
                  i tried ansi versión but i can't use it because return me error with the third argument?

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on 17 Feb 2017, 12:32 last edited by
                  #14

                  @RIVOPICO

                  Here u ask it to use UNICODE version.
                  so now it likes RT_RCDATA

                  Please go to definition of RT_RCDATA and see what it is.
                  Most likely a unicode str.

                  1 Reply Last reply
                  1
                  • R Offline
                    R Offline
                    RIVOPICO
                    wrote on 17 Feb 2017, 12:42 last edited by RIVOPICO
                    #15

                    yeah but i tried unicode version and return me error:

                    The specified resource name cannot be found in the image file.
                    

                    So i think with ansi version will be solved. so i will check in the page thanks for your recommendation.

                    1 Reply Last reply
                    1
                    • C Offline
                      C Offline
                      Chris Kawa
                      Lifetime Qt Champion
                      wrote on 17 Feb 2017, 14:31 last edited by
                      #16

                      RT_RCDATA is a macro that expands to MAKEINTRESOURCE(10), which expands to either MAKEINTRESOURCEA(10) or MAKEINTRESOURCEW(10) when UNICODE is defined or not.
                      So just replace RT_RCDATA in my exmples with either MAKEINTRESOURCEA(10) or MAKEINTRESOURCEW(10).

                      R 1 Reply Last reply 17 Feb 2017, 16:04
                      1
                      • C Chris Kawa
                        17 Feb 2017, 14:31

                        RT_RCDATA is a macro that expands to MAKEINTRESOURCE(10), which expands to either MAKEINTRESOURCEA(10) or MAKEINTRESOURCEW(10) when UNICODE is defined or not.
                        So just replace RT_RCDATA in my exmples with either MAKEINTRESOURCEA(10) or MAKEINTRESOURCEW(10).

                        R Offline
                        R Offline
                        RIVOPICO
                        wrote on 17 Feb 2017, 16:04 last edited by RIVOPICO
                        #17

                        @Chris-Kawa Thanks a lot your answer solve my dude thanks a lot. The system of resources of Qt is awesome and more easy to use so it's better. Anyways i was trying to understand more about windows api and with these explications i understand now thanks.

                        1 Reply Last reply
                        0

                        • Login

                        • Login or register to search.
                        • First post
                          Last post
                        0
                        • Categories
                        • Recent
                        • Tags
                        • Popular
                        • Users
                        • Groups
                        • Search
                        • Get Qt Extensions
                        • Unsolved