Fixed the generation of C# for Virtual function with std::string params (#878)

Fixes #877

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -1492,6 +1492,7 @@ namespace CppSharp.Generators.CSharp
             }
 
             var marshals = new List<string>();
+            var numBlocks = 0;
             for (int i = 0; i < method.Parameters.Count; i++)
             {
                 var param = method.Parameters[i];
@@ -1515,6 +1516,11 @@ namespace CppSharp.Generators.CSharp
                     Write(marshal.Context.Before);
 
                 marshals.Add(marshal.Context.Return);
+                if (ctx.HasCodeBlock)
+                {
+                    PushIndent();
+                    numBlocks++;
+                }
             }
 
             var hasReturn = !method.OriginalReturnType.Type.IsPrimitiveType(PrimitiveType.Void);
@@ -1568,6 +1574,9 @@ namespace CppSharp.Generators.CSharp
                     WriteLine("return {0};", marshal.Context.Return);
                 }
             }
+
+            for (var i = 0; i < numBlocks; ++i)
+                WriteCloseBraceIndent();
         }
 
         private void InvokeProperty(Declaration method, IEnumerable<string> marshals)

tests/Common/Common.Tests.cs

@@ -765,4 +765,14 @@ This is a very long string. This is a very long string. This is a very long stri
         var v = Common.FuncUnion(ut);
         Assert.AreEqual(20, v);
     }
+
+    [Test]
+    public void TestVirtualFuncWithStringParams()
+    {
+        using (var VirtFuncWithStringParam = new ImplementsVirtualFunctionsWithStringParams())
+        {
+            VirtFuncWithStringParam.PureVirtualFunctionWithStringParams("anyRandomString");
+            Assert.That(VirtFuncWithStringParam.VirtualFunctionWithStringParam("anyRandomString").Equals(5));
+        }
+    }
 }

tests/Common/Common.cpp

@@ -756,3 +756,28 @@ int HasCopyAndMoveConstructor::getField()
 {
     return field;
 }
+
+HasVirtualFunctionsWithStringParams::HasVirtualFunctionsWithStringParams()
+{
+}
+
+HasVirtualFunctionsWithStringParams::~HasVirtualFunctionsWithStringParams()
+{
+}
+
+ImplementsVirtualFunctionsWithStringParams::ImplementsVirtualFunctionsWithStringParams()
+{
+}
+
+ImplementsVirtualFunctionsWithStringParams::~ImplementsVirtualFunctionsWithStringParams()
+{
+}
+
+void ImplementsVirtualFunctionsWithStringParams::PureVirtualFunctionWithStringParams(std::string testString)
+{
+}
+
+int HasVirtualFunctionsWithStringParams::VirtualFunctionWithStringParam(std::string testString)
+{
+    return 5;
+}

tests/Common/Common.h

@@ -1281,3 +1281,20 @@ public:
 private:
     int field;
 };
+
+class DLL_API HasVirtualFunctionsWithStringParams
+{
+public:
+    HasVirtualFunctionsWithStringParams();
+    ~HasVirtualFunctionsWithStringParams();
+    virtual void PureVirtualFunctionWithStringParams(std::string testString) = 0;
+    virtual int VirtualFunctionWithStringParam(std::string testString);
+};
+
+class DLL_API ImplementsVirtualFunctionsWithStringParams : public HasVirtualFunctionsWithStringParams
+{
+public:
+    ImplementsVirtualFunctionsWithStringParams();
+    ~ImplementsVirtualFunctionsWithStringParams();
+    virtual void PureVirtualFunctionWithStringParams(std::string testString);
+};