Adds optional parameter nativeInteropSearchPath to SQLiteApiWin32() t…

src/SQLite.Net.Platform.Win32/SQLite.Net.Platform.Win32.csproj

@@ -52,6 +52,7 @@
     <Compile Include="ReflectionServiceWin32.cs" />
     <Compile Include="SQLiteApiWin32.cs" />
     <Compile Include="SQLiteApiWin32Internal.cs" />
+    <Compile Include="SQLiteApiWin32InternalConfiguration.cs" />
     <Compile Include="SQLitePlatformWin32.cs" />
     <Compile Include="StopwatchFactoryWin32.cs" />
     <Compile Include="VolatileServiceWin32.cs" />

src/SQLite.Net.Platform.Win32/SQLiteApiWin32.cs

@@ -6,6 +6,12 @@ namespace SQLite.Net.Platform.Win32
 {
     public class SQLiteApiWin32 : ISQLiteApiExt
     {
+        public SQLiteApiWin32(string nativeInteropSearchPath = null)
+        {
+            if (nativeInteropSearchPath  != null)
+                SQLiteApiWin32InternalConfiguration.NativeInteropSearchPath = nativeInteropSearchPath;
+        }
+
         public Result Open(byte[] filename, out IDbHandle db, int flags, IntPtr zvfs)
         {
             IntPtr dbPtr;

src/SQLite.Net.Platform.Win32/SQLiteApiWin32InternalConfiguration.cs

@@ -0,0 +1,7 @@
+namespace SQLite.Net.Platform.Win32
+{
+    internal static class SQLiteApiWin32InternalConfiguration
+    {
+        public static string NativeInteropSearchPath { get; set; }
+    }
+}

src/SQLite.Net.Platform.Win32/SQLitePlatformWin32.cs

@@ -4,9 +4,9 @@ namespace SQLite.Net.Platform.Win32
 {
     public class SQLitePlatformWin32 : ISQLitePlatform
     {
-        public SQLitePlatformWin32()
+        public SQLitePlatformWin32(string nativeInteropSearchPath = null)
         {
-            SQLiteApi = new SQLiteApiWin32();
+            SQLiteApi = new SQLiteApiWin32(nativeInteropSearchPath);
             StopwatchFactory = new StopwatchFactoryWin32();
             ReflectionService = new ReflectionServiceWin32();
             VolatileService = new VolatileServiceWin32();

src/SQLite.Net.Platform.Win32/SQliteApiWin32Internal.cs

@@ -10,19 +10,42 @@ internal static class SQLiteApiWin32Internal
     {
         static SQLiteApiWin32Internal()
         {
-            // load native library
             int ptrSize = IntPtr.Size;
-            string relativePath = ptrSize == 8 ? @"x64\SQLite.Interop.dll" : @"x86\SQLite.Interop.dll";
-            string assemblyCurrentPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
-            string assemblyInteropPath = Path.Combine(assemblyCurrentPath, relativePath);
+            var architectureDirectory = (ptrSize == 8 ? "x64" : "x86");
+            var interopFilename = "SQLite.Interop.dll";
 
-            // try relative to assembly first, if that does not exist try relative to working dir
-            string interopPath = File.Exists(assemblyInteropPath) ? assemblyInteropPath : relativePath;
+            string interopPath = null;
+            if (!string.IsNullOrWhiteSpace(SQLiteApiWin32InternalConfiguration.NativeInteropSearchPath))
+            {
+                // a NativeInteropSearchPath is given, so we try to find the file name there
+                var fileInSearchPath = Path.Combine(SQLiteApiWin32InternalConfiguration.NativeInteropSearchPath, interopFilename);
+                if (File.Exists(fileInSearchPath))
+                {
+                    interopPath = fileInSearchPath;
+                }
+                else
+                {
+                    var fileInSearchPathWithArchitecture = Path.Combine(SQLiteApiWin32InternalConfiguration.NativeInteropSearchPath, architectureDirectory, interopFilename);
+                    if (File.Exists(fileInSearchPathWithArchitecture))
+                        interopPath = fileInSearchPathWithArchitecture;
+                }
+            }
+
+            if (interopPath == null)
+            {
+                // no NativeInteropSearchPath given (or nothing found using this path) so load native library from assembly execution direcotry
+                string assemblyCurrentPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
+                string relativePath = architectureDirectory + "\\" + interopFilename;
+                string assemblyInteropPath = Path.Combine(assemblyCurrentPath, architectureDirectory, interopFilename);
+
+                // try relative to assembly first, if that does not exist try relative to working dir
+                interopPath = File.Exists(assemblyInteropPath) ? assemblyInteropPath : relativePath;                
+            }
 
             IntPtr ret = LoadLibrary(interopPath);
             if (ret == IntPtr.Zero)
             {
-                throw new Exception("Failed to load native sqlite library");
+                throw new Exception("Failed to load native sqlite library from " + interopPath);
             }
         }