41 nativeaot cant marshal safearray (#42)

Replaced SafeArray marshalling with custom marshalling to get GetNames method working with NativeAOT and added missing method doc.
MartinKuschnik · Dec 3, 2024 · a717554 · a717554
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commit a717554
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Showing 6 changed files with 91 additions and 31 deletions.
diff --git a/WmiLight.Native/WmiLight.Native.rc b/WmiLight.Native/WmiLight.Native.rc
@@ -43,8 +43,8 @@ END
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 6,8,0,0
- PRODUCTVERSION 6,8,0,0
+ FILEVERSION 6,9,0,0
+ PRODUCTVERSION 6,9,0,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -70,12 +70,12 @@ BEGIN
     VALUE "FileDescription", "The native part of the WmiLight lib."
 #endif
 
-            VALUE "FileVersion", "6.8.0.0"
+            VALUE "FileVersion", "6.9.0.0"
             VALUE "InternalName", "WmiLight.Native"
             VALUE "LegalCopyright", "Copyright 2024 Martin Kuschnik"
             VALUE "OriginalFilename", "WmiLight.Native.dll"
             VALUE "ProductName", "WmiLight"
-            VALUE "ProductVersion", "6.8.0.0"
+            VALUE "ProductVersion", "6.9.0.0"
         END
     END
     BLOCK "VarFileInfo"

diff --git a/WmiLight/Internal/NativeMethods.cs b/WmiLight/Internal/NativeMethods.cs
@@ -143,7 +143,7 @@ public static extern HResult Get(
         public static extern HResult GetType(IntPtr pClassObject, [MarshalAs(UnmanagedType.LPWStr)] string propertyName, out CimType cimType);
 
         [DllImport(NATIVE_DLL_NAME, CallingConvention = CallingConvention.StdCall)]
-        public static extern HResult GetNames(IntPtr pClassObject, [MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_BSTR)] out string[] pNames);
+        public static extern HResult GetNames(IntPtr pClassObject, out IntPtr pNames);
 
         #endregion
 

diff --git a/WmiLight/Internal/SafeArray.cs b/WmiLight/Internal/SafeArray.cs
@@ -0,0 +1,63 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+
+namespace WmiLight
+{
+    internal static class SafeArray
+    {
+        internal static IEnumerable<IntPtr> ForEach(IntPtr pSafeArray, uint nDim = 1)
+        {
+            int lBound, uBound;
+
+            HResult hResult = NativeMethods.SafeArrayGetLBound(pSafeArray, nDim, out lBound);
+
+            if (hResult.Failed)
+                throw (Exception)hResult;
+
+            hResult = NativeMethods.SafeArrayGetUBound(pSafeArray, nDim, out uBound);
+
+            if (hResult.Failed)
+                throw (Exception)hResult;
+
+            for (int i = lBound; i <= uBound; i++)
+            {
+                hResult = NativeMethods.SafeArrayGetElement(pSafeArray, i, out IntPtr pElement);
+
+                if (hResult.Failed)
+                    throw (Exception)hResult;
+
+                yield return pElement;
+            }
+        }
+
+        internal static IEnumerable<string> ForEachBSTR(IntPtr pSafeArray, uint nDim = 1)
+        {
+            foreach (IntPtr pElement in ForEach(pSafeArray, nDim))
+            {
+                string stringValue = Marshal.PtrToStringBSTR(pElement);
+
+                Marshal.FreeBSTR(pElement);
+
+                yield return stringValue;
+            }
+        }
+
+        internal static int GetLength(IntPtr pSafeArray, uint nDim = 1)
+        {
+            int lBound, uBound;
+
+            HResult hResult = NativeMethods.SafeArrayGetLBound(pSafeArray, nDim, out lBound);
+
+            if (hResult.Failed)
+                throw (Exception)hResult;
+
+            hResult = NativeMethods.SafeArrayGetUBound(pSafeArray, nDim, out uBound);
+
+            if (hResult.Failed)
+                throw (Exception)hResult;
+
+            return uBound - lBound + 1;
+        }
+    }
+}
diff --git a/WmiLight/Wbem/WbemClassObject.cs b/WmiLight/Wbem/WbemClassObject.cs
@@ -83,14 +83,20 @@ internal IEnumerable<string> GetNames()
             if (this.Disposed)
                 throw new ObjectDisposedException(nameof(WbemClassObject));
 
-            string[] names;
-
-            HResult hResult = NativeMethods.GetNames(this, out names);
+            HResult hResult = NativeMethods.GetNames(this, out IntPtr pSafeArrayWithNames);
 
             if (hResult.Failed)
                 throw (Exception)hResult;
 
-            return names;
+            try
+            {
+                foreach (string name in SafeArray.ForEachBSTR(pSafeArrayWithNames))
+                    yield return name;
+            }
+            finally
+            {
+                NativeMethods.SafeArrayDestroy(pSafeArrayWithNames);
+            }
         }
 
         internal void GetMethod(string methodName, out WbemClassObject inSignatur, out WbemClassObject outSignatur)
@@ -475,33 +481,17 @@ private static T[] VariantToArray<T>(ref VARIANT value, CimType type)
             if (arrayDims != 1)
                 throw new NotSupportedException("Only single-dimensional arrays are supported");
 
-            int lBound, uBound;
-
-            HResult hResult = NativeMethods.SafeArrayGetLBound(value.Object, arrayDims, out lBound);
+            T[] array = new T[SafeArray.GetLength(value.Object, arrayDims)];
 
-            if (hResult.Failed)
-                throw (Exception)hResult;
+            int index = 0;
 
-            hResult = NativeMethods.SafeArrayGetUBound(value.Object, arrayDims, out uBound);
-
-            if (hResult.Failed)
-                throw (Exception)hResult;
-
-            T[] array = new T[uBound - lBound + 1];
-
-            for (int i = lBound; i <= uBound; i++)
+            foreach (IntPtr pElement in SafeArray.ForEach(value.Object, arrayDims))
             {
-                VARIANT variant = default;
+                VARIANT variant = new VARIANT() { vt = value.vt & ~VARENUM.VT_ARRAY, Object = pElement };
 
                 try
                 {
-                    variant.vt = value.vt & ~VARENUM.VT_ARRAY;
-                    hResult = NativeMethods.SafeArrayGetElement(value.Object, i, out variant.Object);
-
-                    if (hResult.Failed)
-                        throw (Exception)hResult;
-
-                    array[i] = (T)VariantToObject(ref variant, type);
+                    array[index++] = (T)VariantToObject(ref variant, type);
                 }
                 finally
                 {

diff --git a/WmiLight/WmiLight.csproj b/WmiLight/WmiLight.csproj
@@ -23,7 +23,7 @@
 	</Target>
 	<PropertyGroup />
 	<PropertyGroup>
-		<Version>6.8.0</Version>
+		<Version>6.9.0</Version>
 		<PackageId>WmiLight</PackageId>
 		<Authors>Martin Kuschnik</Authors>
 		<Company>Martin Kuschnik</Company>

diff --git a/WmiLight/WmiMethodParameters.cs b/WmiLight/WmiMethodParameters.cs
@@ -141,6 +141,13 @@ public void SetPropertyValue(string propertyName, string propertyValue)
             this.signatur.Put(propertyName, propertyValue);
         }
 
+        #region Description
+        /// <summary>
+        /// Sets the value of a property.
+        /// </summary>
+        /// <param name="propertyName">The name of the property that should be changed.</param>
+        /// <param name="propertyValue">The new property value.</param>
+        #endregion
         public void SetPropertyValue(string propertyName, string[] propertyValue)
         {
             this.signatur.Put(propertyName, propertyValue);