Some languages, such as C++, allow you to throw exceptions of any managed type. Other languages, such as Microsoft C# and Visual Basic, require that every thrown exception be derived from the Exception class. To maintain compatibility between languages, the common language runtime (CLR) wraps objects that do not derive from Exception in a RuntimeWrappedException object.

You can use the RuntimeCompatibilityAttribute class to specify whether exceptions should appear wrapped inside catch blocks and exception filters for an assembly. Many language compilers, including the Microsoft C# and Visual Basic compilers, apply this attribute by default to specify the wrapping behavior.

Note that the runtime still wraps exceptions even if you use the RuntimeCompatibilityAttribute class to specify that you do not want them wrapped. In this case, exceptions are unwrapped only inside catch blocks or exception filters.

The following code example demonstrates how to throw a String object as an exception in C++ and catch it using a RuntimeWrappedException object.

using namespace System;
using namespace System::Runtime::CompilerServices;

[assembly:RuntimeCompatibilityAttribute(WrapNonExceptionThrows = true)]; 

void run()
{
    try
    {
        throw gcnew String("This is a string");

    }
    catch(RuntimeWrappedException^ e)
    {
        Console::WriteLine("RuntimeWrappedException caught!");
    }
}

int main()
{
    run();

    return 0;
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework

Reference