Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All
Important This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here.

Version Issues for Value Types Nested in Native Types (C++/CLI)

Consider a signed (strong name) assembly component used to build a client assembly. The component contains a value type that is used in the client as the type for a member of a native union, a class, or an array. If a future version of the component changes the size or layout of the value type, the client must be recompiled.

Create a keyfile with sn.exe (sn -k mykey.snk).

The following sample is the component.

// nested_value_types.cpp
// compile with: /clr /LD
using namespace System::Reflection;
[assembly:AssemblyVersion("1.0.0.*"), 
assembly:AssemblyKeyFile("mykey.snk")];

public value struct S {
   int i;
   void Test() {
      System::Console::WriteLine("S.i = {0}", i);
   }
};

This sample is the client:

// nested_value_types_2.cpp
// compile with: /clr
#using <nested_value_types.dll>

struct S2 {
   S MyS1, MyS2;
};

int main() {
   S2 MyS2a, MyS2b;
   MyS2a.MyS1.i = 5;
   MyS2a.MyS2.i = 6;
   MyS2b.MyS1.i = 10;
   MyS2b.MyS2.i = 11;

   MyS2a.MyS1.Test();
   MyS2a.MyS2.Test();
   MyS2b.MyS1.Test();
   MyS2b.MyS2.Test();
}

S.i = 5
S.i = 6
S.i = 10
S.i = 11

Comments

However, if you add another member to struct S in nested_value_types.cpp, (for example, double d;) and recompile the component without recompiling the client, the result is an unhandled exception (of type System.IO.FileLoadException).

Community Additions

ADD
Show:
© 2015 Microsoft