Add array-passing example

MyClientCpp/Main.cpp

@@ -85,6 +85,13 @@ int main() {
             double pi = cruncher->ComputePi();
             std::wcout << L"pi = " << pi << std::endl;
 
+            CComSafeArray<BYTE> arr;
+            arr.Attach(cruncher->ComputeValues(4));
+            std::wcout << L"array: [";
+            for (unsigned int i = 0; i < arr.GetCount(); ++i)
+                std::wcout << (int)arr[(LONG)i] << L", ";
+            std::wcout << L"]\n";
+
             auto callback = CreateLocalInstance<MyClient>();
             server->Subscribe(callback);
 

MyClientCs/Program.cs

@@ -16,6 +16,9 @@ static void CommunicateWithServer()
                 double pi = cruncher.ComputePi();
                 Console.WriteLine($"pi = {pi}");
 
+                byte[] values = cruncher.ComputeValues(4);
+                Console.WriteLine("ComputeValues: ["+ string.Join(", ", values) + "]");
+
                 // release reference to help GC clean up (not strctly needed)
                 cruncher = null;
             }

MyExeServerCpp/MyServerImpl.hpp

@@ -37,6 +37,20 @@ class ATL_NO_VTABLE NumberCruncher :
         return S_OK;
     }
 
+    HRESULT STDMETHODCALLTYPE raw_ComputeValues(unsigned int count, /*out*/SAFEARRAY** vals) override {
+        if (!vals)
+            return E_INVALIDARG;
+
+        // populate array with values
+        CComSafeArray<BYTE> tmp(count);
+        for (unsigned int i = 0; i < count; ++i)
+            tmp[(LONG)i] = (BYTE)i;
+
+        *vals = tmp.Detach();
+        return S_OK;
+    }
+
+
     BEGIN_COM_MAP(NumberCruncher)
         COM_INTERFACE_ENTRY(INumberCruncher)
     END_COM_MAP()

MyExeServerCs/MyServerImpl.cs

@@ -142,5 +142,14 @@ public double ComputePi ()
         {
             return Math.PI;
         }
+
+        public byte[] ComputeValues(uint count)
+        {
+            byte[] values = new byte[count];
+            for (uint i = 0; i < count; i++)
+                values[i] = (byte)i;
+
+            return values;
+        }
     }
 }

MyInterfaces/MyInterfaces.idl

@@ -88,6 +88,9 @@ interface IMyClient : IUnknown {
 interface INumberCruncher : IUnknown {
     [helpstring("Compute the value of pi")]
     HRESULT ComputePi([out, retval] double *ret);
+
+    [helpstring("Get an array with magic values.")]
+    HRESULT ComputeValues([in] unsigned int count, [out, retval] SAFEARRAY(BYTE)* vals);
 };
 
 [object,