make gRPC C# nuget work with new project.json style projects

1 files changed, 15 insertions, 9 deletions

diff --git a/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs b/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs
index 47308f8c9e..5a80746101 100644
--- a/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs
+++ b/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs
@@ -32,8 +32,6 @@
 #endregion
 
 using System;
-using System.Collections.Concurrent;
-using System.Diagnostics;
 using System.IO;
 using System.Reflection;
 using System.Runtime.InteropServices;
@@ -63,14 +61,9 @@ namespace Grpc.Core.Internal
         readonly string libraryPath;
         readonly IntPtr handle;
 
-        public UnmanagedLibrary(string libraryPath)
+        public UnmanagedLibrary(string[] libraryPathAlternatives)
         {
-            this.libraryPath = GrpcPreconditions.CheckNotNull(libraryPath);
-
-            if (!File.Exists(this.libraryPath))
-            {
-                throw new FileNotFoundException("Error loading native library. File does not exist.", this.libraryPath);
-            }
+            this.libraryPath = FirstValidLibraryPath(libraryPathAlternatives);
 
             Logger.Debug("Attempting to load native library \"{0}\"", this.libraryPath);
 
@@ -139,6 +132,19 @@ namespace Grpc.Core.Internal
             throw new InvalidOperationException("Unsupported platform.");
         }
 
+        private static string FirstValidLibraryPath(string[] libraryPathAlternatives)
+        {
+            GrpcPreconditions.CheckArgument(libraryPathAlternatives.Length > 0, "libraryPathAlternatives cannot be empty.");
+            foreach (var path in libraryPathAlternatives)
+            {
+                if (File.Exists(path))
+                {
+                    return path;
+                }
+            }
+            throw new FileNotFoundException(String.Format("Error loading native library. Not found in any of the possible locations {0}", libraryPathAlternatives));
+        }
+
         private static class Windows
         {
             [DllImport("kernel32.dll")]