diff --git a/samples/CSharp/OCCTProxy/OCCTProxy.cpp b/samples/CSharp/OCCTProxy/OCCTProxy.cpp
index 91d43646fe..cb0b0267da 100644
--- a/samples/CSharp/OCCTProxy/OCCTProxy.cpp
+++ b/samples/CSharp/OCCTProxy/OCCTProxy.cpp
@@ -32,6 +32,8 @@
 //wrapper of pure C++ classes to ref classes
 #include <NCollection_Haft.h>
 
+#include <vcclr.h>
+
 // list of required OCCT libraries
 #pragma comment(lib, "TKernel.lib")
 #pragma comment(lib, "TKMath.lib")
@@ -45,6 +47,24 @@
 #pragma comment(lib, "TKStl.lib")
 #pragma comment(lib, "TKVrml.lib")
 
+//! Auxiliary tool for converting C# string into UTF-8 string.
+static TCollection_AsciiString toAsciiString (String^ theString)
+{
+  if (theString == nullptr)
+  {
+    return TCollection_AsciiString();
+  }
+
+  pin_ptr<const wchar_t> aPinChars = PtrToStringChars (theString);
+  const wchar_t* aWCharPtr = aPinChars;
+  if (aWCharPtr == NULL
+  || *aWCharPtr == L'\0')
+  {
+    return TCollection_AsciiString();
+  }
+  return TCollection_AsciiString (aWCharPtr);
+}
+
 /// <summary>
 /// Proxy class encapsulating calls to OCCT C++ classes within 
 /// C++/CLI class visible from .Net (CSharp)
@@ -93,14 +113,14 @@ public:
   /// Make dump of current view to file
   /// </summary>
   /// <param name="theFileName">Name of dump file</param>
-  bool Dump(char *theFileName)
+  bool Dump(const TCollection_AsciiString& theFileName)
   {
     if (myView().IsNull())
     {
       return false;
     }
     myView()->Redraw();
-    return myView()->Dump(theFileName) != Standard_False;
+    return myView()->Dump(theFileName.ToCString()) != Standard_False;
   }
 
   /// <summary>
@@ -731,28 +751,18 @@ public:
   /// <param name="theFileName">Name of import file</param>
   bool ImportBrep(System::String^ theFileName)
   {
-    bool isResult = false;
-    int aLength = theFileName->Length;
-    char* aFilename = new char[aLength+1];
-    for(int i = 0; i<aLength; i++)
-    {
-      aFilename[i] = (char)theFileName->ToCharArray()[i];
-    }
-    aFilename[aLength] = '\0';
-    isResult = ImportBrep(aFilename);
-    return isResult;
+    return ImportBrep (toAsciiString (theFileName));
   }
 
   /// <summary>
   ///Import BRep file
   /// </summary>
   /// <param name="theFileName">Name of import file</param>
-  bool ImportBrep(char* theFileName)
+  bool ImportBrep (const TCollection_AsciiString& theFileName)
   {
-    Standard_CString aFileName = (Standard_CString) theFileName;
     TopoDS_Shape aShape;
     BRep_Builder aBuilder;
-    Standard_Boolean isResult = BRepTools::Read(aShape,aFileName,aBuilder);
+    Standard_Boolean isResult = BRepTools::Read(aShape,theFileName.ToCString(),aBuilder);
     if (!isResult)
     {
       return false;
@@ -766,11 +776,10 @@ public:
   ///Import Step file
   /// </summary>
   /// <param name="theFileName">Name of import file</param>
-  bool ImportStep(char* theFileName)
+  bool ImportStep(const TCollection_AsciiString& theFileName)
   {
-    Standard_CString aFileName = (Standard_CString) theFileName;
     STEPControl_Reader aReader;
-    IFSelect_ReturnStatus aStatus = aReader.ReadFile(aFileName);
+    IFSelect_ReturnStatus aStatus = aReader.ReadFile(theFileName.ToCString());
     if ( aStatus == IFSelect_RetDone )
     {
       bool isFailsonly = false;
@@ -805,11 +814,10 @@ public:
   ///Import Iges file
   /// </summary>
   /// <param name="theFileName">Name of import file</param>
-  bool ImportIges(char* theFileName)
+  bool ImportIges(const TCollection_AsciiString& theFileName)
   {
-    Standard_CString aFileName = (Standard_CString) theFileName;
     IGESControl_Reader aReader;
-    int aStatus = aReader.ReadFile( aFileName );
+    int aStatus = aReader.ReadFile( theFileName.ToCString() );
 
     if ( aStatus == IFSelect_RetDone )
     {
@@ -830,7 +838,7 @@ public:
   ///Export BRep file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportBRep(char* theFileName)
+  bool ExportBRep(const TCollection_AsciiString& theFileName)
   {
     myAISContext()->InitSelected();
     if (!myAISContext()->MoreSelected())
@@ -840,14 +848,14 @@ public:
 
     Handle(AIS_InteractiveObject) anIO = myAISContext()->SelectedInteractive();
     Handle(AIS_Shape) anIS = Handle(AIS_Shape)::DownCast(anIO);
-    return BRepTools::Write (anIS->Shape(), (Standard_CString)theFileName) != Standard_False;
+    return BRepTools::Write (anIS->Shape(), theFileName.ToCString()) != Standard_False;
   }
 
   /// <summary>
   ///Export Step file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportStep(char* theFileName)
+  bool ExportStep(const TCollection_AsciiString& theFileName)
   {
     STEPControl_StepModelType aType = STEPControl_AsIs;
     IFSelect_ReturnStatus aStatus;
@@ -864,7 +872,7 @@ public:
       }
     }
 
-    aStatus = aWriter.Write( (Standard_CString)theFileName );
+    aStatus = aWriter.Write(theFileName.ToCString());
     if ( aStatus != IFSelect_RetDone )
     {
       return false;
@@ -877,7 +885,7 @@ public:
   ///Export Iges file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportIges(char* theFileName)
+  bool ExportIges(const TCollection_AsciiString& theFileName)
   {
     IGESControl_Controller::Init();
     IGESControl_Writer aWriter( Interface_Static::CVal( "XSTEP.iges.unit" ),
@@ -892,14 +900,14 @@ public:
     }
 
     aWriter.ComputeModel();
-    return aWriter.Write( (Standard_CString)theFileName) != Standard_False;
+    return aWriter.Write(theFileName.ToCString()) != Standard_False;
   }
 
   /// <summary>
   ///Export Vrml file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportVrml(char* theFileName)
+  bool ExportVrml(const TCollection_AsciiString& theFileName)
   {
     TopoDS_Compound aRes;
     BRep_Builder aBuilder;
@@ -919,7 +927,7 @@ public:
     }
 
     VrmlAPI_Writer aWriter;
-    aWriter.Write( aRes, (Standard_CString)theFileName );
+    aWriter.Write(aRes, theFileName.ToCString());
 
     return true;
   }
@@ -928,7 +936,7 @@ public:
   ///Export Stl file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportStl(char* theFileName)
+  bool ExportStl(const TCollection_AsciiString& theFileName)
   {
     TopoDS_Compound aComp;
     BRep_Builder aBuilder;
@@ -947,7 +955,7 @@ public:
     }
 
     StlAPI_Writer aWriter;
-    aWriter.Write( aComp, (Standard_CString)theFileName );
+    aWriter.Write(aComp, theFileName.ToCString());
     return true;
   }
 
@@ -960,14 +968,8 @@ public:
   bool TranslateModel(System::String^ theFileName, int theFormat, bool theIsImport)
   {
     bool isResult;
-    int aLength = theFileName->Length;
-    char* aFilename = new char[aLength+1];
-    for(int i = 0; i<aLength; i++)
-    {
-      aFilename[i] = (char)theFileName->ToCharArray()[i];
-    }
-    aFilename[aLength] = '\0';
 
+    const TCollection_AsciiString aFilename = toAsciiString (theFileName);
     if (theIsImport)
     {
       switch(theFormat)
diff --git a/samples/CSharp/OCCTProxy_D3D/OCCTProxyD3D.cpp b/samples/CSharp/OCCTProxy_D3D/OCCTProxyD3D.cpp
index 08bc578c34..4b4411cea7 100644
--- a/samples/CSharp/OCCTProxy_D3D/OCCTProxyD3D.cpp
+++ b/samples/CSharp/OCCTProxy_D3D/OCCTProxyD3D.cpp
@@ -39,6 +39,8 @@
 //wrapper of pure C++ classes to ref classes
 #include <NCollection_Haft.h>
 
+#include <vcclr.h>
+
 // list of required OCCT libraries
 #pragma comment(lib, "TKernel.lib")
 #pragma comment(lib, "TKMath.lib")
@@ -55,6 +57,24 @@
 
 #pragma comment(lib, "D3D9.lib")
 
+//! Auxiliary tool for converting C# string into UTF-8 string.
+static TCollection_AsciiString toAsciiString (String^ theString)
+{
+  if (theString == nullptr)
+  {
+    return TCollection_AsciiString();
+  }
+
+  pin_ptr<const wchar_t> aPinChars = PtrToStringChars (theString);
+  const wchar_t* aWCharPtr = aPinChars;
+  if (aWCharPtr == NULL
+  || *aWCharPtr == L'\0')
+  {
+    return TCollection_AsciiString();
+  }
+  return TCollection_AsciiString (aWCharPtr);
+}
+
 /// <summary>
 /// Proxy class encapsulating calls to OCCT C++ classes within
 /// C++/CLI class visible from .Net (CSharp)
@@ -109,14 +129,14 @@ public:
   /// Make dump of current view to file
   /// </summary>
   /// <param name="theFileName">Name of dump file</param>
-  bool Dump (const char* theFileName)
+  bool Dump (const TCollection_AsciiString& theFileName)
   {
     if (myView().IsNull())
     {
       return false;
     }
     myView()->Redraw();
-    return myView()->Dump (theFileName) != Standard_False;
+    return myView()->Dump (theFileName.ToCString()) != Standard_False;
   }
 
   /// <summary>
@@ -709,28 +729,18 @@ public:
   /// <param name="theFileName">Name of import file</param>
   bool ImportBrep (System::String^ theFileName)
   {
-    bool  isResult  = false;
-    int   aLength   = theFileName->Length;
-    char* aFilename = new char[aLength + 1];
-    for(int i = 0; i < aLength; ++i)
-    {
-      aFilename[i] = (char )theFileName->ToCharArray()[i];
-    }
-    aFilename[aLength] = '\0';
-    isResult = ImportBrep (aFilename);
-    delete[] aFilename;
-    return isResult;
+    return ImportBrep (toAsciiString (theFileName));
   }
 
   /// <summary>
   ///Import BRep file
   /// </summary>
   /// <param name="theFileName">Name of import file</param>
-  bool ImportBrep (char* theFileName)
+  bool ImportBrep (const TCollection_AsciiString& theFileName)
   {
     TopoDS_Shape aShape;
     BRep_Builder aBuilder;
-    if (!BRepTools::Read (aShape, theFileName, aBuilder))
+    if (!BRepTools::Read (aShape, theFileName.ToCString(), aBuilder))
     {
       return false;
     }
@@ -746,10 +756,10 @@ public:
   ///Import Step file
   /// </summary>
   /// <param name="theFileName">Name of import file</param>
-  bool ImportStep (char* theFileName)
+  bool ImportStep (const TCollection_AsciiString& theFileName)
   {
     STEPControl_Reader aReader;
-    if (aReader.ReadFile (theFileName) != IFSelect_RetDone)
+    if (aReader.ReadFile (theFileName.ToCString()) != IFSelect_RetDone)
     {
       return false;
     }
@@ -779,10 +789,10 @@ public:
   ///Import Iges file
   /// </summary>
   /// <param name="theFileName">Name of import file</param>
-  bool ImportIges (char* theFileName)
+  bool ImportIges (const TCollection_AsciiString& theFileName)
   {
     IGESControl_Reader aReader;
-    if (aReader.ReadFile (theFileName) != IFSelect_RetDone)
+    if (aReader.ReadFile (theFileName.ToCString()) != IFSelect_RetDone)
     {
       return false;
     }
@@ -798,7 +808,7 @@ public:
   ///Export BRep file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportBRep (char* theFileName)
+  bool ExportBRep (const TCollection_AsciiString& theFileName)
   {
     myAISContext()->InitSelected();
     if (!myAISContext()->MoreSelected())
@@ -808,14 +818,14 @@ public:
 
     Handle(AIS_Shape) anIS = Handle(AIS_Shape)::DownCast (myAISContext()->SelectedInteractive());
     return !anIS.IsNull()
-         && BRepTools::Write (anIS->Shape(), theFileName);
+         && BRepTools::Write (anIS->Shape(), theFileName.ToCString());
   }
 
   /// <summary>
   ///Export Step file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportStep (char* theFileName)
+  bool ExportStep (const TCollection_AsciiString& theFileName)
   {
     STEPControl_StepModelType aType = STEPControl_AsIs;
     STEPControl_Writer        aWriter;
@@ -833,14 +843,14 @@ public:
         return false;
       }
     }
-    return aWriter.Write (theFileName) == IFSelect_RetDone;
+    return aWriter.Write (theFileName.ToCString()) == IFSelect_RetDone;
   }
 
   /// <summary>
   ///Export Iges file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportIges (char* theFileName)
+  bool ExportIges (const TCollection_AsciiString& theFileName)
   {
     IGESControl_Controller::Init();
     IGESControl_Writer aWriter (Interface_Static::CVal ("XSTEP.iges.unit"),
@@ -857,14 +867,14 @@ public:
     }
 
     aWriter.ComputeModel();
-    return aWriter.Write (theFileName) != Standard_False;
+    return aWriter.Write (theFileName.ToCString()) != Standard_False;
   }
 
   /// <summary>
   ///Export Vrml file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportVrml (char* theFileName)
+  bool ExportVrml (const TCollection_AsciiString& theFileName)
   {
     TopoDS_Compound aRes;
     BRep_Builder    aBuilder;
@@ -880,7 +890,7 @@ public:
     }
 
     VrmlAPI_Writer aWriter;
-    aWriter.Write (aRes, theFileName);
+    aWriter.Write (aRes, theFileName.ToCString());
     return true;
   }
 
@@ -888,7 +898,7 @@ public:
   ///Export Stl file
   /// </summary>
   /// <param name="theFileName">Name of export file</param>
-  bool ExportStl (char* theFileName)
+  bool ExportStl (const TCollection_AsciiString& theFileName)
   {
     TopoDS_Compound aComp;
     BRep_Builder    aBuilder;
@@ -904,7 +914,7 @@ public:
     }
 
     StlAPI_Writer aWriter;
-    aWriter.Write (aComp, theFileName);
+    aWriter.Write (aComp, theFileName.ToCString());
     return true;
   }
 
@@ -917,14 +927,7 @@ public:
   bool TranslateModel (System::String^ theFileName, int theFormat, bool theIsImport)
   {
     bool  isResult  = false;
-    int   aLength   = theFileName->Length;
-    char* aFilename = new char[aLength + 1];
-    for (int aCharIter = 0; aCharIter < aLength; ++aCharIter)
-    {
-      aFilename[aCharIter] = (char)theFileName->ToCharArray()[aCharIter];
-    }
-    aFilename[aLength] = '\0';
-
+    const TCollection_AsciiString aFilename = toAsciiString (theFileName);
     if (theIsImport)
     {
       switch (theFormat)
@@ -946,7 +949,6 @@ public:
         case 5: isResult = Dump (aFilename);      break;
       }
     }
-    delete[] aFilename;
     return isResult;
   }