Question

I want to load this Class library :

namespace ClassLibrary1
{
    public class Class1
    {
        public Class1()
        {
        }
        public static int Sum(int a, int b)
        {
            return a + b;
        }
    }
}

I have a wcf service which returns to me a byte[] array (ClassLibrary1) i can not load this assembly

static void Main(string[] args)
{
    FileTransferService.ApplicationHostServiceClient client = new FileTransferService.ApplicationHostServiceClient();

    FileTransferService.AssemblyPackage[] asmbs = client.GetFile();
    //var newDomain = AppDomain.CreateDomain("FooBar", null, null);
    foreach (FileTransferService.AssemblyPackage item in asmbs) 
    {
        byte[] mybuffer = item.Buffer;
        new AssemblyLoader().LoadAndCall(mybuffer);
    }
}

public class AssemblyLoader : MarshalByRefObject
{
    public void LoadAndCall(byte[] binary)
    {
        Assembly loadedAssembly = AppDomain.CurrentDomain.Load(binary);
        object[] tt = { 3, 6 };
        Type typ = loadedAssembly.GetType("ClassLibrary1.Class1");
        MethodInfo minfo = typ.GetMethod("Sum", BindingFlags.Public);
        int x = (int)minfo.Invoke(null, tt);
        Console.WriteLine(x);
    }
}

Error return to me in this method : Assembly loadedAssembly = AppDomain.CurrentDomain.Load(binary);

ERROR:

BADIMAGEFORMAT EXCEPTION
Could not load file or assembly '4096 bytes loaded from Client2, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.

EXCEPTION :

Bad IL format

i have googling this kind of error but no exact solution. i want to load my assembly using AppDomain.

Answer 1

The first thing to check in this scenario is that the byte[] you received is exactly identical to the original, as there are many ways of making a mess of handing a chunk of binary. Perhaps write the file to disk (File.WriteAllBytes) and your favourite file compare tool, or use something like base-64 or a sha-1 hash to validate the contents. I strongly suspect you’ll find it isn’t the same.