Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • World
  • Users
  • Groups
Skins
  • Light
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (No Skin)
  • No Skin
Collapse
Code Project
  1. Home
  2. General Programming
  3. C / C++ / MFC
  4. CString to const char*

CString to const char*

Scheduled Pinned Locked Moved C / C++ / MFC
question
14 Posts 4 Posters 0 Views 1 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.
  • _ _Flaviu

    I am trying to convert a CString to const char*, and I have tried some versions:

    CString sTemp("abcd");
    const char* chTemp = (LPCSTR)(LPCTSTR)sTemp;

    is one of them, but in chTemp I have only one letter from sTemp, not whole string ... why ?

    V Offline
    V Offline
    Victor Nijegorodov
    wrote on last edited by
    #2

    Is your build a UNICODE one? Then you will have to convert, not just cast your CString data. See [WideCharToMultiByte function (stringapiset.h) | Microsoft Docs](https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte) or ATL macros like W2A

    _ 3 Replies Last reply
    0
    • V Victor Nijegorodov

      Is your build a UNICODE one? Then you will have to convert, not just cast your CString data. See [WideCharToMultiByte function (stringapiset.h) | Microsoft Docs](https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte) or ATL macros like W2A

      _ Offline
      _ Offline
      _Flaviu
      wrote on last edited by
      #3

      I have converted the project to multi-byte character set (was unicode) and the behavior is the same ...

      1 Reply Last reply
      0
      • V Victor Nijegorodov

        Is your build a UNICODE one? Then you will have to convert, not just cast your CString data. See [WideCharToMultiByte function (stringapiset.h) | Microsoft Docs](https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte) or ATL macros like W2A

        _ Offline
        _ Offline
        _Flaviu
        wrote on last edited by
        #4

        I have tried this also:

        const char\* chTemp = (const char\*)sTemp.GetBuffer(0);
        sTemp.ReleaseBuffer();
        TRACE(">>>>>>>>>>>>>>>>>>>%s\\n", chTemp);
        

        the project is not multi-byte ... the same result, just one letter (first letter) from the string ...

        V D 2 Replies Last reply
        0
        • _ _Flaviu

          I have tried this also:

          const char\* chTemp = (const char\*)sTemp.GetBuffer(0);
          sTemp.ReleaseBuffer();
          TRACE(">>>>>>>>>>>>>>>>>>>%s\\n", chTemp);
          

          the project is not multi-byte ... the same result, just one letter (first letter) from the string ...

          V Offline
          V Offline
          Victor Nijegorodov
          wrote on last edited by
          #5

          _Flaviu wrote:

          the project is not multi-byte

          Is it "not multi-byte" or "multi-byte"?

          _ 1 Reply Last reply
          0
          • V Victor Nijegorodov

            _Flaviu wrote:

            the project is not multi-byte

            Is it "not multi-byte" or "multi-byte"?

            _ Offline
            _ Offline
            _Flaviu
            wrote on last edited by
            #6

            Sorry, is multi-byte .. .anyway, if the project is unicode or is multi-byte, is the same thing.

            V 1 Reply Last reply
            0
            • V Victor Nijegorodov

              Is your build a UNICODE one? Then you will have to convert, not just cast your CString data. See [WideCharToMultiByte function (stringapiset.h) | Microsoft Docs](https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte) or ATL macros like W2A

              _ Offline
              _ Offline
              _Flaviu
              wrote on last edited by
              #7

              Is obviously something in project settings, because I have tried this code in a new test project and goes fine as multi-byte project ... as unicode, the same result.

              L 1 Reply Last reply
              0
              • _ _Flaviu

                Sorry, is multi-byte .. .anyway, if the project is unicode or is multi-byte, is the same thing.

                V Offline
                V Offline
                Victor Nijegorodov
                wrote on last edited by
                #8

                Try these tests:

                CStringA ansiText("TestA");
                LPCSTR ansi = (LPCSTR)ansiText;
                TRACE("%s\n", ansi);

                CString someText("Test");
                ansi = (LPCSTR)someText;
                TRACE("%s\n", ansi);

                What is the result?

                _ 1 Reply Last reply
                0
                • V Victor Nijegorodov

                  Try these tests:

                  CStringA ansiText("TestA");
                  LPCSTR ansi = (LPCSTR)ansiText;
                  TRACE("%s\n", ansi);

                  CString someText("Test");
                  ansi = (LPCSTR)someText;
                  TRACE("%s\n", ansi);

                  What is the result?

                  _ Offline
                  _ Offline
                  _Flaviu
                  wrote on last edited by
                  #9

                  with the first try:

                  CStringA ansiText("TestA");
                  LPCSTR ansi = (LPCSTR)ansiText;
                  TRACE("%s\\n", ansi);
                  

                  the result is TestA for the second try, I got an error:

                  1>d:\tempx\test\testdoc.cpp(53): error C2440: 'type cast' : cannot convert from 'CString' to 'LPCSTR'

                  at

                  CString someText("Test");
                  ansi = (LPCSTR)someText;    // <-- here is the error
                  TRACE("%s\\n", ansi);
                  

                  The project is unicode.

                  V 1 Reply Last reply
                  0
                  • _ _Flaviu

                    with the first try:

                    CStringA ansiText("TestA");
                    LPCSTR ansi = (LPCSTR)ansiText;
                    TRACE("%s\\n", ansi);
                    

                    the result is TestA for the second try, I got an error:

                    1>d:\tempx\test\testdoc.cpp(53): error C2440: 'type cast' : cannot convert from 'CString' to 'LPCSTR'

                    at

                    CString someText("Test");
                    ansi = (LPCSTR)someText;    // <-- here is the error
                    TRACE("%s\\n", ansi);
                    

                    The project is unicode.

                    V Offline
                    V Offline
                    Victor Nijegorodov
                    wrote on last edited by
                    #10

                    _Flaviu wrote:

                    for the second try, I got an error:

                    1>d:\tempx\test\testdoc.cpp(53): error C2440: 'type cast' : cannot convert from 'CString' to 'LPCSTR'

                    at

                    CString someText("Test");
                    ansi = (LPCSTR)someText; // <-- here is the error
                    TRACE("%s\n", ansi);

                    The project is unicode.

                    Of course you get the error since the CString contains the wide char text! Either change the build to be MBCS/ANSI or convert CString to wchar_t* (or use _T() macro).

                    _ 1 Reply Last reply
                    0
                    • _ _Flaviu

                      Is obviously something in project settings, because I have tried this code in a new test project and goes fine as multi-byte project ... as unicode, the same result.

                      L Offline
                      L Offline
                      Lost User
                      wrote on last edited by
                      #11

                      You cannot cast a CStingW (which is what the class will be in a Unicode environment) to an LPCSTR (which is const char*). You need to show again the actual failing code, and check the project settings.

                      1 Reply Last reply
                      0
                      • V Victor Nijegorodov

                        _Flaviu wrote:

                        for the second try, I got an error:

                        1>d:\tempx\test\testdoc.cpp(53): error C2440: 'type cast' : cannot convert from 'CString' to 'LPCSTR'

                        at

                        CString someText("Test");
                        ansi = (LPCSTR)someText; // <-- here is the error
                        TRACE("%s\n", ansi);

                        The project is unicode.

                        Of course you get the error since the CString contains the wide char text! Either change the build to be MBCS/ANSI or convert CString to wchar_t* (or use _T() macro).

                        _ Offline
                        _ Offline
                        _Flaviu
                        wrote on last edited by
                        #12

                        "build to be MBCS/ANSI" you meant multi-byte project ?

                        L 1 Reply Last reply
                        0
                        • _ _Flaviu

                          "build to be MBCS/ANSI" you meant multi-byte project ?

                          L Offline
                          L Offline
                          Lost User
                          wrote on last edited by
                          #13

                          Go to Project -> Properties -> General and make sure Character set is set to "Use Multi-Byte Charachter Set".

                          1 Reply Last reply
                          0
                          • _ _Flaviu

                            I have tried this also:

                            const char\* chTemp = (const char\*)sTemp.GetBuffer(0);
                            sTemp.ReleaseBuffer();
                            TRACE(">>>>>>>>>>>>>>>>>>>%s\\n", chTemp);
                            

                            the project is not multi-byte ... the same result, just one letter (first letter) from the string ...

                            D Offline
                            D Offline
                            David Crow
                            wrote on last edited by
                            #14

                            _Flaviu wrote:

                            TRACE(">>>>>>>>>>>>>>>>>>>%s\n", chTemp);

                            What if you try:

                            TRACE(">>>>>>>>>>>>>>>>>>>%S\n", chTemp); // capital S

                            "One man's wage rise is another man's price increase." - Harold Wilson

                            "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

                            "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

                            1 Reply Last reply
                            0
                            Reply
                            • Reply as topic
                            Log in to reply
                            • Oldest to Newest
                            • Newest to Oldest
                            • Most Votes


                            • Login

                            • Don't have an account? Register

                            • Login or register to search.
                            • First post
                              Last post
                            0
                            • Categories
                            • Recent
                            • Tags
                            • Popular
                            • World
                            • Users
                            • Groups