Databases
StackOverflow2013
Postsdbo
POC++ DLL calling a function implemented in the consuming application
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POC++ DLL calling a function implemented in the consuming application
    primarykey
    data
    text
    <p>How to call a post-implemented function (e.g., function pointers or virtual functions implemented in the consuming application) with a complex return type from a DLL function?</p> <p>I tried the following scheme but got errors.</p> <p>Test.h:</p> <pre><code>#ifdef _DLL_IMPL #define DLL_EXPORT __declspec(dllexport) #else #define DLL_EXPORT __declspec(dllimport) #endif typedef string (*test)(void); extern DLL_EXPORT test __test; DLL_EXPORT int launch(); </code></pre> <p>Test.cpp:</p> <pre><code>#define _DLL_IMPL #include "Test.h" test __test = 0; int launch() { string a = __test(); return 0; } </code></pre> <p>And the consuming application goes like:</p> <p>Main.cpp:</p> <pre><code>#include "Test.h" #pragma comment(lib, "Test.lib") string test_impl() { string a = "test"; return a; } int main(int args, char** argv) { __test = &amp;test_impl; return launch(); } </code></pre> <p>And I got a subsequent error message:</p> <pre><code>Windows has triggered a breakpoint in TestRun.exe. This may be due to a corruption of the heap, which indicates a bug in TestRun.exe or any of the DLLs it has loaded. This may also be due to the user pressing F12 while TestRun.exe has focus. The output window may have more diagnostic information. </code></pre> <p>I don't know what exactly was going on. Error also occurred when I tried a return type of a char pointer, which would be created in the consuming application using a new operator and would be freed in a DLL function using a delete[] operator.</p> <p>Can someone explain the reason why the error happens and suggest me some solution to this scheme? Thank you!</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USbestmike007
    plurals
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POC++ DLL calling a function implemented in the consuming application
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POC++ DLL calling a function implemented in the consuming application
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI don't believe you can new in the app and delete in the dll. That would cause heap corruption.
      singulars
      1. POC++ DLL calling a function implemented in the consuming application
      1. USJoeFish
    2. COYes, I also believe that's the reason why it does not work. I don't really know how to implement the scheme I described (i.e., calling a function implemented in the app).
      singulars
      1. POC++ DLL calling a function implemented in the consuming application
      1. USbestmike007
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload