I can't figure out for the life of me how to import a class declared, defined and implemented within a dll into a host app using any GNU build systems. The two compiler suites I have are Dev C++ and the newer Code::Blocks.
After that I tried to create a dll with Dev-C and it worked, but here is the real problem: I cant import the Dev-C dll in Visual Studio. Is there a way to import the dll to the Visual Studio Projekt or do you guys know a good tutorial for creating a dll in Visual Studio 2017? Blog » How to create and use DLL in C. Posted on 06 May 2011 13:24. The following steps apply for visual studio 2008. Step 1: Create the project for the DLL. Let's create a simple Win32 Console DLL: Visual Studio File New Project Win32 Console Application. If the DLL includes a COM type library, you can use the #import statement as such: #import dllname.dll Otherwise, you'll need to link with an import library, and you'll need to provide a function prototype for your compiler. Typically the import library and a header file with.
I have no problem with this using any Microsoft products that I have. The two Microsoft products I have are Visual C++ 6 and eMbedded Visual C++ 4.0.
Below is a simple test dll & host app to show my difficulty, along with Compile Log tab and Compiler Tab from Dev C++ (The CodeBlocks errors are exactly the same). The dll - dllCBox - just creates and exports a simple class to calculate the volume of a box. The host app simply tries to import the class, declare a CBox, and output its volume. Note that this is just a test case I put together to concisely show the problem. In the real situation I create a String class of my own within a dll where I create several grid custom controls. In the host that creates instances of the custom controls I also have access to my string class. This architecture is something I use to good advantage frequently, rather than implementing the same string class in the dll & the host app, which would be wasteful. Anyway, here is the example...
Import Dll Visual Studio
Packing DLLs in your EXE. By Thiadmer Riemersma, June 01, 2002 DLLpack is a tool that allows DLLs to be embedded inside an executable and extracted the first time a function from the DLL is called. Sep 05, 2012 Ok in that case I have C/CLI wrapper around the c dll. How can I use in the winRT project? My goal is to use the C/CLI dll in a metro app.
Here is a simple Host app that just uses the CBox class to get the
volume of a 3 by 4 by 5 box...
volume of a 3 by 4 by 5 box...
Here is output from either VC++ 6 or Windows CE eMbedded VC++ 4.0 on Handheld. There it works like a charm. The
mechanism there is to tell the IDE that the host project is dependent on the dll project.
mechanism there is to tell the IDE that the host project is dependent on the dll project.
/*
//Output fro VC++ 6 or on handheld with eMbedded VC++ 4.0
//Output fro VC++ 6 or on handheld with eMbedded VC++ 4.0
Called CBox() Constructor
box1.Volume()=60.000000
Called CBox() Destructor
Press any key to continue
*/
box1.Volume()=60.000000
Called CBox() Destructor
Press any key to continue
*/
With either of the GNU compiler suites (Dev C++ or CodeBlocks) there is an option to specify 'parameters' to the Host app build. With Dev C++ you go to the 'Project' menu and execute 'Project Options'. That brings up a dialog with tabs and if you choose the Linker tab you can add the proper export lib from the dll which you wish the host app to link against. libdllCBox.a is what is produced by Dev C++ & CodeBlocks using the GNU compilers. Below are the error messages from Dev C++. The ones from CodeBlocks are about the same....
Compile Log Tab
Compiler: Default compiler
Building Makefile: 'C:CodeDev-CppProjectsdllCBoxMakefile.win'
Executing make...
make.exe -f 'C:CodeDev-CppProjectsdllCBoxMakefile.win' all
Compiler: Default compiler
Building Makefile: 'C:CodeDev-CppProjectsdllCBoxMakefile.win'
Executing make...
make.exe -f 'C:CodeDev-CppProjectsdllCBoxMakefile.win' all
g++.exe -c Main.cpp -o Main.o
-I'C:/Dev-Cpp/lib/gcc/mingw32/3.4.2/include'
-I'C:/Dev-Cpp/include/c++/3.4.2/backward' -I'C:/Dev-Cpp/include/c++/3.4.2/mingw32'
-I'C:/Dev-Cpp/include/c++/3.4.2' -I'C:/Dev-Cpp/include'
-I'C:/Dev-Cpp/lib/gcc/mingw32/3.4.2/include'
-I'C:/Dev-Cpp/include/c++/3.4.2/backward' -I'C:/Dev-Cpp/include/c++/3.4.2/mingw32'
-I'C:/Dev-Cpp/include/c++/3.4.2' -I'C:/Dev-Cpp/include'
g++.exe Main.o -o 'Boxes.exe' -L'C:/Dev-Cpp/lib' libdllCBox.a
Main.o(.text+0x81):Main.cpp: undefined reference to `_imp___ZN4CBoxC1Eddd'
Main.o(.text+0x95):Main.cpp: undefined reference to `_imp___ZN4CBox6VolumeEv'
Main.o(.text+0xbe):Main.cpp: undefined reference to `_imp___ZN4CBoxD1Ev'
Main.o(.text+0xea):Main.cpp: undefined reference to `_imp___ZN4CBoxD1Ev'
collect2: ld returned 1 exit status
make.exe: *** [Boxes.exe] Error 1
Execution terminated
Main.o(.text+0x95):Main.cpp: undefined reference to `_imp___ZN4CBox6VolumeEv'
Main.o(.text+0xbe):Main.cpp: undefined reference to `_imp___ZN4CBoxD1Ev'
Main.o(.text+0xea):Main.cpp: undefined reference to `_imp___ZN4CBoxD1Ev'
collect2: ld returned 1 exit status
make.exe: *** [Boxes.exe] Error 1
Execution terminated
Compiler Tab
[Linker error] undefined reference to `_imp___ZN4CBoxC1Eddd'
[Linker error] undefined reference to `_imp___ZN4CBox6VolumeEv'
[Linker error] undefined reference to `_imp___ZN4CBoxD1Ev'
[Linker error] undefined reference to `_imp___ZN4CBoxD1Ev'
ld returned 1 exit status
C:CodeDev-CppProjectsdllCBoxMakefile.win [Build Error] [Boxes.exe] Error 1
By the way, I noted from the above Make file that the apparent linker line was...
C# Import C++ Dll
-L'C:/Dev-Cpp/lib' libdllCBox.a
and that got me to wandering what directory the linker was looking to find libdllCBox.a, so I pasted a copy of it right in the compiler's lib directory along with all the other compiler libs, but it didn't do any good.
C++ Import Dll
Also, I might point out that the above techniques I've described of adding the export lib from the dll to the parameters list box under Linker Settings works fine in Dev C++ or CodeBlocks when it is simple functions being exported from the dll; however, it most
certainly doesn't work for exporting classes and that is why I'm asking. I simply don't know how to do it. I expect its some little simple thingie/setting somewhere, and I'd love to know what it is. Can anyone help me with this?
certainly doesn't work for exporting classes and that is why I'm asking. I simply don't know how to do it. I expect its some little simple thingie/setting somewhere, and I'd love to know what it is. Can anyone help me with this?
C++ Export Function Dll
I did a search here at daniweb and came with some discussion of this issue with regard to Microsoft compilers, but didn't find anything about the GNU stuff. Here is that link...
Exporting Class From dll
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Ancient Dragon5,243
why is that class declared extern 'C' ? C programs can't call c++ classes, to that declaration is pointless.