抛出System.ExecutionEngineException

Question

This exception is being thrown when this line of code gets executed

retobj = Marshal.PtrToStructure( buffer, anytype );

I don't know what is causing this because, the application I am attempting to run works fine on other developers machines here.

public static object RawDeserialize(byte[] rawdatas, Type anytype) 
{
    int rawsize = Marshal.SizeOf(anytype);

    if (rawsize > rawdatas.Length)
    {  
        return null;
    }

    IntPtr buffer = Marshal.AllocHGlobal(rawsize);
    object retobj = null;

    try 
    {
         Marshal.Copy(rawdatas, 0, buffer, rawsize);
         retobj = Marshal.PtrToStructure(buffer, anytype);
    }
    finally 
    {
         Marshal.FreeHGlobal(buffer);
    }

    return retobj;
}

I've tried repairing the .NET Compact Framework multiple times and nothing seems to work, does anyone know of a solution to this?

Answer 1

If you'll debug your program you'll find out that the following line throws the exception:

 retobj = Marshal.PtrToStructure(buffer, anytype); 

The main cause is that the marshalling tool does not know how to marshal your type. This has many possible causes, two of the most common I know are:

1. Nested structures in the struct (of type anytype)

   • solved by prefixing your struct with

     [StructLayout(LayoutKind.Sequential, Pack = 1)]

2. Nested arrays.

   • solved by prefixing array with

     [MarshalAs(UnmanagedType.ByValArray, SizeConst = 512)]

Hope it helps.