Managed C++/CLI

Freak3017-Jun-13 0:31

Freak30

17-Jun-13 0:31

C# string[] becomes array<String^>^ in C++.
List<string> becomes List<String^>^.

Remember you need to allocate managed types with gcnew in C++. (The regular new is for unmanaged types.) The conversion is done automatically on function call. In fact it isn't even a real conversion, as the meaning/memory layout is the same, just the expression looks different. So you declare a function taking a array<String^>^ and pass in a string[] or the other way araound.

Keep in mind, you can't have C# and C++ in the same module (exe/dll) so you need to separate the code into different ones.

John Schroedl17-Jun-13 4:30

17-Jun-13 4:30

Freak30's answer is good and thinking about it I realize you may want to get the string value to native C++ code instead of just to C++/CLI. If that's the case, you'll want to look into the marshal_as templates.

ex.

C++

#include <msclr\marshal.h>

. . .

const char * message = "test";
String^ managed = marshal_as<String^>( message );

taibc17-Jun-13 4:34

taibc

17-Jun-13 4:34

Thanks Freak30,

I am using Visual Studio 2010. I tried to send string[] in C# to string[] in C++, but not successful

In C#, I used below codes:

[DllImport("DgnShpConverter.dll")]
public static extern Boolean ConvertDgnToShp(string source, string destinationPath, string     shpFileName, string [] strArray);

And in C++ (file DgnShpConverter.dll), I used below codes:

C++

__declspec(dllexport) bool ConvertDgnToShp(const char* sourceFile, const char *destinationPath, const char *shpFileName, string myArray[])
{
    // do something  ....
}

Do you know how to fix this ?

Thanks and kind regards,
Tai

Karthik Kalyanasundaram17-Jun-13 20:13

Karthik Kalyanasundaram

17-Jun-13 20:13

Please check this link Interoperation: C# and native Win32 C++ code; arrays of strings[^]

Do more work
Make more mistakes
Learn more things

Getting assembly details (descripton, version, etc) set for a C++/CLI assembly

taibc18-Jun-13 17:21

taibc

18-Jun-13 17:21

Hi Karthik,

Thank you very much. Your link is very useful. I will try it.

Kind regards,

Tai

John Schroedl12-Jun-13 5:29

Re: Getting assembly details (descripton, version, etc) set for a C++/CLI assembly

12-Jun-13 5:29

I have migrated a bunch of C++/CLI code out of my main mixed-mode executable into a DLL but Windows explorer is not showing the details for the DLL. I set them like this in my AssemblyInfo.cpp:

C++

[assembly:AssemblyTitleAttribute("MyDLL")];
[assembly:AssemblyDescriptionAttribute("A cool component")];
[assembly:AssemblyConfigurationAttribute("")];
[assembly:AssemblyCompanyAttribute("My Company")];
[assembly:AssemblyProductAttribute("My Product")];
[assembly:AssemblyCopyrightAttribute("Copyright © My Corp 2013")];
[assembly:AssemblyTrademarkAttribute("")];
[assembly:AssemblyCultureAttribute("")];
[assembly:AssemblyVersionAttribute("2.0.0.0")];

I also have a C# DLL with settings just like this in its AssemblyInfo.cs and they ARE shown in the Details pane of the Explorer Properties dialog.

I suspect I'll need to add a .rc file with VERSIONINFO but was hoping to avoid duplicating info like that (and it's a small hassle to hook into the build).

Has anyone here faced and solved this issue?
John

John Schroedl12-Jun-13 10:15

12-Jun-13 10:15

I'll answer my own question for future visitors. Yes, adding the VERSIONINFO resource was necessary. And, it was easier than I thought - just right-click on Resource Files folder in Solution Explorer, Add > Resource... and select VERSIONINFO.

John

windows sdk

Member 259538310-Jun-13 6:02

Member 2595383

10-Jun-13 6:02

Odd that Microsoft puts their debug annotations into their code now (winnt.h)-does that mean they'll finish testing at the customer premises?

Daniel Kilsdonk

Re: windows sdk

Richard MacCutchan10-Jun-13 7:05

VC++ import dll command causes error C2872 'ambiguous symbol' in comdefsp.h

10-Jun-13 7:05

Odd that you did not read http://www.codeproject.com/Messages/1329679/The-Cplusplus-CLI-is-for-managed-and-mixed-mode-Cp.aspx[^] before posting.

Use the best guess

devguy242-Jun-13 23:34

devguy24

2-Jun-13 23:34

Hello everyone,

so I'm using VC++ 2008 and I've got a large solution made up of several different interconnected projects, some of which are DLL's (no CLR). In one of these DLL's I'm trying to import an EXTERNAL Visual Basic dll using the command #import "C:\path\to\my\DLL\file.dll" . If I use this command in one of my .cpp files, it works. If on the other hand, I use it in one of my .h files, I then get the following compile errors in the files ocidl.h and comdefsp.h. I noticed that the .tlh and .tli files generated by the #import command include the file comdef.h. There are other files in my project that include the file comdef.h. Could this be the reason for the conflict?

Error   1236    "solution_name" error C2872: 'IDropTarget' : ambiguous symbol   C:\Program Files\Microsoft SDKs\Windows\v6.0A\include\ocidl.h   3949
Error   1237    "solution_name" error C2872: 'IServiceProvider' : ambiguous symbol  C:\Program Files\Microsoft SDKs\Windows\v6.0A\include\ocidl.h   6238
Error   1238    "solution_name" error C2872: 'IDataObject' : ambiguous symbol   c:\program files (x86)\microsoft visual studio 9.0\vc\include\comdefsp.h    216
Error   1239    "solution_name" error C2872: 'IDataObject' : ambiguous symbol   c:\program files (x86)\microsoft visual studio 9.0\vc\include\comdefsp.h    216
Error   1240    "solution_name" error C2872: 'IDropTarget' : ambiguous symbol   c:\program files (x86)\microsoft visual studio 9.0\vc\include\comdefsp.h    246
Error   1242    "solution_name" error C2872: 'IMessageFilter' : ambiguous symbol    c:\program files (x86)\microsoft visual studio 9.0\vc\include\comdefsp.h    771
Error   1243    "solution_name" error C2872: 'IMessageFilter' : ambiguous symbol    c:\program files (x86)\microsoft visual studio 9.0\vc\include\comdefsp.h    771
Error   1244    "solution_name" error C2872: 'IServiceProvider' : ambiguous symbol  c:\program files (x86)\microsoft visual studio 9.0\vc\include\comdefsp.h    1041
Error   1245    "solution_name" error C2872: 'IServiceProvider' : ambiguous

Re: VC++ import dll command causes error C2872 'ambiguous symbol' in comdefsp.h

Member 259538311-Jun-13 12:10

Member 2595383

11-Jun-13 12:10

since IDropTarget is a type, and it is referenced in ocidl.h, 'ambiguous' implies two definitions for the same, one must not disclude that the two definitions ARE the same and this would point to the common error of an include file, including itself.

An include file should never include itself! But include files are notorious for including themselves vis-à-vis other include files. While it is of poor craftsmanship, it IS promoted in K&R C manual itself when they proscribe something akin to:
#IFNDEF THISFILENOTALREADYREAD
#define THISFILENOTALREADYREAD
....
your h file: 'thisfile'
...
#ENDIF

If this is not the case, kindly submit the result of this search complete solution
'IDropTarget'

Also, there is a switch you can throw that will indicate the include files as they are included. That would be helpful.

Daniel Kilsdonk

Type casting in C++\CLI project

for study23-May-13 20:41

for study

23-May-13 20:41

I have project which I am compiling with /clr. I have a class like below..

ref class A
{
public:
 void CheckValue(void * test);
 typedef ref struct val
{
 std::string *x;
}val_t;

};

in my implementation I ahve to use something like below..

void A::CheckValue(void *test)
{
 a::val_t^ allVal = (a::val_t^)test;
}

in my main I have used like..

int main()
{
A^ obj = gcnew A();
a::val_t valObj = new std::string("Test");
obj->CheckValue((void*)valObj);
}

I am getting type cast error and two places - obj->CheckValue((void*)valObj); and at obj->CheckValue((void*)valObj); error C2440: 'type cast' : cannot convert from 'void*' to 'A::val_t ^'

This snippet is just to show behavior at my end and I ahve to use it this way only. Earlier I was running it using non /clr so it compiled fine.

Now question I have how can I make this type casting work in C++/CLI type project?

Re: Type casting in C++\CLI project

David Knechtges24-May-13 3:29

David Knechtges

24-May-13 3:29

You are mixing the two - managed and unmanaged - void * is unmanaged and val_t is managed. You need to do a conversion in order to get this to work. Here is a similar question:

http://stackoverflow.com/questions/6903208/cli-c-void-to-systemobject[^]

Re: Type casting in C++\CLI project

Member 259538311-Jun-13 12:41

Member 2595383

11-Jun-13 12:41

As we know C++ disdains poor typing. Some day it will achieve Pascal or Ada greatness!

Try:
desired_ptrtype newone=static_cast<desired_ptrtype>(voidstarptr)

Daniel Kilsdonk

etting Access Violation Exception -Attempted to read or write protected memory - when trying to convert unmanaged array of structures into managed class in Vb.Net (VS2010,4.0 framework) in Windows 7 -64 bit mode.

VijaySandur25-Apr-13 3:44

VijaySandur

25-Apr-13 3:44

Getting Access Violation Exception when trying to convert unmanaged array of structures into managed in Vb.Net(VS2010,4.0 framework) in Windows 7 -64 bit mode.
Sample Source Code

<structlayout(layoutkind.sequential, charset:="CharSet.Ansi)"> _
Public Class vb_menu_dotnet
Public level As Short
Public menu_id As String
Public short_desc As String
Public parent_id As String
Public access As Short
Public flag As Short
Public menu_desc As String
End Class

Dim current As IntPtr
Dim outArray As IntPtr
Dim manArray(100) As vb_menu_dotnet

vb_dotnet_get_menu_hierarchy(p_menu_handle, p_apl_id, outArray) //C API call
current = outArray

Dim j As Integer
For j = 1 To 100
manArray(j) = New vb_menu_dotnet()
Marshal.PtrToStructure(current, manArray(j)) //Access Violation Exception

Vijay

Re: etting Access Violation Exception -Attempted to read or write protected memory - when trying to convert unmanaged array of structures into managed class in Vb.Net (VS2010,4.0 framework) in Windows 7 -64 bit mode.

John Schroedl25-Apr-13 7:52

25-Apr-13 7:52

You may need to try a VB.NET forum. This is for C++/CLI code.

Richard MacCutchan25-Apr-13 22:29

25-Apr-13 22:29

Dim current As IntPtr
Dim outArray As IntPtr
Dim manArray(100) As vb_menu_dotnet
 
vb_dotnet_get_menu_hierarchy(p_menu_handle, p_apl_id, outArray) //C API call

You have not initialised any of the pointers that you are sending to the C-language library. Take a look at this P/Invoke tutorial[^] for more information.

Use the best guess

Tripurari Chaudhary13-May-13 23:43

Tripurari Chaudhary

13-May-13 23:43

Hi ,
whatever database u r acessing or data retrieval policy u might be using for e.g INI file,must be in Read Mode,Try to make it Write protected

Richard MacCutchan13-May-13 23:50

Re: Ad Hoc routing protocol

13-May-13 23:50

Did you actually read the OP's question?

Use the best guess

Tripurari Chaudhary13-May-13 23:44

Tripurari Chaudhary

13-May-13 23:44

ASM

Hi ,
whatever database  u r acessing or data retrieval policy u might be using for e.g INI file,must be in Read Mode,Try to make it Write protected

Ad Hoc routing protocol

3bood.ghzawi18-Apr-13 2:43

3bood.ghzawi

18-Apr-13 2:43

can anyone help me finding the source code or the simulation of the Dual Busy Tone Multiple Access (DBTMA) protocol ????

regards...
Sniff | :^)

Richard MacCutchan18-Apr-13 4:27