Public Function XLGetSheetInfo(ByVal fileName As String) As List(Of String)
   Dim sheets As List(Of String) = New List(Of String)
   Dim xlPackage As SpreadsheetDocument = SpreadsheetDocument.Open(fileName, False)
   Dim workbook As WorkbookPart = xlPackage.WorkbookPart
   Dim workbookstr As Stream = workbook.GetStream
   Dim doc As XmlDocument = New XmlDocument
   doc.Load(workbookstr)
   Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(doc.NameTable)
   nsManager.AddNamespace("default", doc.DocumentElement.NamespaceURI)
   Dim nodelist As XmlNodeList = doc.SelectNodes("//default:sheets/default:sheet", nsManager)
   For Each node As XmlNode In nodelist
      Dim sheetName As String = String.Empty
      sheetName = node.Attributes("name").Value
      sheets.Add(sheetName)
   Next
   Return sheets
End Function

public static List<string> XLGetSheetInfo(string fileName)
{
   List<string> sheets = new List<string>();

   using (SpreadsheetDocument xlPackage = SpreadsheetDocument.Open(fileName, false))
   {
      WorkbookPart workbook = xlPackage.WorkbookPart;
      Stream workbookstr = workbook.GetStream();
      XmlDocument doc = new XmlDocument();
      doc.Load(workbookstr);

      XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);
      nsManager.AddNamespace("default", doc.DocumentElement.NamespaceURI);
      XmlNodeList nodelist = doc.SelectNodes("//default:sheets/default:sheet", nsManager);

      foreach (XmlNode node in nodelist)
      {
         string sheetName = string.Empty;
         sheetName = node.Attributes["name"].Value;
         sheets.Add(sheetName);
      }
   }
   return sheets;
}

Public Sub XLWrite2Cell(ByVal fileName As String, ByVal sheetName As String, ByVal addressName As String)
   Const worksheetNamespace As String = "http://schemas.openxmlformats.org/spreadsheetml/2006/main"
   Dim xlPackage As SpreadsheetDocument = SpreadsheetDocument.Open(fileName, True)
   '  Get the main document part (workbook.xml).
   Dim workbookPart As WorkbookPart = xlPackage.WorkbookPart
   '  Load the contents of the workbook.
   Dim doc As XmlDocument = New XmlDocument
   doc.Load(workbookPart.GetStream)
   '  Create a NamespaceManager to handle the default namespace, 
   '  and create a prefix for the default namespace.
   Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(doc.NameTable)
   nsManager.AddNamespace("d", doc.DocumentElement.NamespaceURI)
   nsManager.AddNamespace("w", worksheetNamespace)
   Dim searchString As String = String.Format("//d:sheet[@name='{0}']", sheetName)
   Dim sheetNode As XmlNode = doc.SelectSingleNode(searchString, nsManager)
   If (Not (sheetNode) Is Nothing) Then
      '  Get the relationship id attribute.
      Dim relationAttribute As XmlAttribute = sheetNode.Attributes("r:id")
      If (Not (relationAttribute) Is Nothing) Then
         Dim relId As String = relationAttribute.Value
         Dim worksheetPart As WorksheetPart = CType(workbookPart.GetPartById(relId), WorksheetPart)
         Dim sheetDoc As XmlDocument = New XmlDocument
         sheetDoc.Load(worksheetPart.GetStream)
         Dim cellNode As XmlNode = sheetDoc.SelectSingleNode(String.Format("//w:sheetData/w:row/w:c[@r='{0}']", addressName), nsManager)
         If (cellNode Is Nothing) Then
            cellNode = sheetDoc.CreateElement("c", worksheetNamespace)
            cellNode.Attributes.Append(sheetDoc.CreateAttribute("r"))
            cellNode.Attributes("r").Value = addressName
            Dim r As System.Text.RegularExpressions.Regex = New System.Text.RegularExpressions.Regex("(?<col>\D+)(?<row>\d+)")
            Dim rowNumber As String = r.Match(addressName).Result("${row}")
            cellNode.Attributes.Append(sheetDoc.CreateAttribute("s"))
            cellNode.Attributes("s").Value = "0"
            Dim rowNode As XmlNode = sheetDoc.SelectSingleNode(String.Format("//w:sheetData/w:row[@r='{0}']", rowNumber), nsManager)
            If (rowNode Is Nothing) Then
               Dim sheetDataNode As XmlNode = sheetDoc.SelectSingleNode("//w:sheetData", nsManager)
               If (Not (sheetDataNode) Is Nothing) Then
                  rowNode = sheetDoc.CreateElement("row", worksheetNamespace)
                  rowNode.Attributes.Append(sheetDoc.CreateAttribute("r"))
                  rowNode.Attributes("r").Value = rowNumber
                  rowNode.AppendChild(cellNode)
                  sheetDataNode.AppendChild(rowNode)
               End If
            Else
               Dim styleAttr As XmlAttribute = rowNode.Attributes("s")
               If (Not (styleAttr) Is Nothing) Then
                  cellNode.Attributes("s").Value = styleAttr.Value
               End If
               Dim biggerNode As XmlNode = Nothing
               For Each node As System.Xml.XmlNode In rowNode.ChildNodes
                  If (Double.Parse(node.Attributes("r").Value) > Double.Parse(addressName)) Then
                     biggerNode = node
                  End If
               Next
               If (biggerNode Is Nothing) Then
                  rowNode.AppendChild(cellNode)
               Else
                  rowNode.InsertBefore(cellNode, biggerNode)
               End If
          End If
      End If
      '  =============
      '  Insert code to work with cellNode here.
      '  =============
      '  For example:
      Dim valueNode As XmlNode = cellNode.SelectSingleNode(".//w:v", nsManager)
      If (valueNode Is Nothing) Then
         valueNode = sheetDoc.CreateElement("v", worksheetNamespace)
         cellNode.AppendChild(valueNode)
      End If
      valueNode.InnerText = "12345"
      '  Note that this will not display string values--those must
      '  be retrieved from the shared strings part.
      '  See the code example that demonstrates retrieving
      '  a value from an Excel cell for the complete code.
      MessageBox.Show(("Value = " + valueNode.InnerText))
      '  Save the worksheet part.
      Dim st As Stream = worksheetPart.GetStream(FileMode.Create)
      sheetDoc.Save(st)
      'xlPackage.Save();
      'doc.Save(workbookPart.GetStream(FileMode.Create));
      '  ============
      '  End example code.
      '  ============
      End If
   End If
End Sub

public static void XLWrite2Cell(string fileName, string sheetName, string addressName)
{
   const string worksheetNamespace = "http://schemas.openxmlformats.org/spreadsheetml/2006/main";

   using (SpreadsheetDocument xlPackage = SpreadsheetDocument.Open(fileName, true))
   {
      //  Get the main document part (workbook.xml).
      WorkbookPart workbookPart = xlPackage.WorkbookPart;
      //  Load the contents of the workbook.
      XmlDocument doc = new XmlDocument();
      doc.Load(workbookPart.GetStream());

      //  Create a NamespaceManager to handle the default namespace, 
      //  and create a prefix for the default namespace.
      XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);
      nsManager.AddNamespace("d", doc.DocumentElement.NamespaceURI);
      nsManager.AddNamespace("w", worksheetNamespace);

      string searchString = string.Format("//d:sheet[@name='{0}']", sheetName);
      XmlNode sheetNode = doc.SelectSingleNode(searchString, nsManager);
      if (sheetNode != null)
      {
         //  Get the relationship id attribute.
         XmlAttribute relationAttribute = sheetNode.Attributes["r:id"];
         if (relationAttribute != null)
         {
            string relId = relationAttribute.Value;

            WorksheetPart worksheetPart = (WorksheetPart)workbookPart.GetPartById(relId);

            XmlDocument sheetDoc = new XmlDocument();
            sheetDoc.Load(worksheetPart.GetStream());

            XmlNode cellNode = sheetDoc.SelectSingleNode(string.Format("//w:sheetData/w:row/w:c[@r='{0}']", addressName), nsManager);
            if (cellNode == null)
            {
               cellNode = sheetDoc.CreateElement("c", worksheetNamespace);
               cellNode.Attributes.Append(sheetDoc.CreateAttribute("r"));
               cellNode.Attributes["r"].Value = addressName;
               System.Text.RegularExpressions.Regex r = new System.Text.RegularExpressions.Regex(@"(?<col>\D+)(?<row>\d+)");
               string rowNumber = r.Match(addressName).Result("${row}");

               cellNode.Attributes.Append(sheetDoc.CreateAttribute("s"));
               cellNode.Attributes["s"].Value = "0";

               XmlNode rowNode = sheetDoc.SelectSingleNode(string.Format("//w:sheetData/w:row[@r='{0}']", rowNumber), nsManager);
               if (rowNode == null)
               {
                  XmlNode sheetDataNode = sheetDoc.SelectSingleNode("//w:sheetData", nsManager);
                  if (sheetDataNode != null)
                  {
                     rowNode = sheetDoc.CreateElement("row", worksheetNamespace);
                     rowNode.Attributes.Append(sheetDoc.CreateAttribute("r"));
                     rowNode.Attributes["r"].Value = rowNumber;
                     rowNode.AppendChild(cellNode);
                     sheetDataNode.AppendChild(rowNode);
                  }
               }
               else
               {
                  XmlAttribute styleAttr = rowNode.Attributes["s"];
                  if (styleAttr != null)
                  {
                     cellNode.Attributes["s"].Value = styleAttr.Value;
                  }
                  XmlNode biggerNode = null;
                  foreach (System.Xml.XmlNode node in rowNode.ChildNodes)
                  {
                     if (double.Parse(node.Attributes["r"].Value) > double.Parse(addressName))
                     {
                        biggerNode = node;
                        break; /* TRANSWARNING: check that break is in correct scope */
                     }
                  }
                  if (biggerNode == null)
                  {
                     rowNode.AppendChild(cellNode);
                  }
                  else
                  {
                     rowNode.InsertBefore(cellNode, biggerNode);
                  }
               }
            }
            //  =============
            //  Insert code to work with cellNode here.
            //  =============
            //  For example:
            XmlNode valueNode = cellNode.SelectSingleNode(".//w:v", nsManager);
            if (valueNode == null)
            {
               valueNode = sheetDoc.CreateElement("v", worksheetNamespace);
               cellNode.AppendChild(valueNode);
            }
            valueNode.InnerText = "12345";
            //  Note that this won't display string values--those must
            //  be retrieved from the shared strings part.
            //  See the code example that demonstrates retrieving
            //  a value from an Excel cell for the complete code.
            MessageBox.Show("Value = " + valueNode.InnerText);

            //  Save the worksheet part.
            Stream st = worksheetPart.GetStream(FileMode.Create);
            sheetDoc.Save(st);
            //xlPackage.Save();
            //doc.Save(workbookPart.GetStream(FileMode.Create));
            //  ============
            //  End example code.
            //  ============
         }
      }
   }
}

Public Function PPTGetSlideTitles(ByVal fileName As String) As List(Of String)
   Const presentationmlNamespace As String = "http://schemas.openxmlformats.org/presentationml/2006/main"
   Dim titles As List(Of String) = New System.Collections.Generic.List(Of String)
   Dim pptDoc As PresentationDocument = PresentationDocument.Open(fileName, False)
   '  Manage namespaces to perform XML XPath queries.
   Dim nt As NameTable = New NameTable
   Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(nt)
   nsManager.AddNamespace("p", presentationmlNamespace)
   For Each slidePart As SlidePart In pptDoc.PresentationPart.SlideParts
      Dim slideDoc As XmlDocument = New XmlDocument(nt)
      slideDoc.Load(slidePart.GetStream)
      Dim titleNode As XmlNode = slideDoc.SelectSingleNode("//p:sp//p:ph[@type='title' or @type='ctrTitle']", nsManager)
      If (Not (titleNode) Is Nothing) Then
         titles.Add(titleNode.ParentNode.ParentNode.ParentNode.InnerText)
      End If
   Next
   Return titles
End Function

public static List>string> PPTGetSlideTitles(string fileName)
{
   const string presentationmlNamespace = "http://schemas.openxmlformats.org/presentationml/2006/main";

   List>string> titles = new System.Collections.Generic.List>string>();

   using (PresentationDocument pptDoc = PresentationDocument.Open(fileName, false))
   {
      //  Manage namespaces to perform Xml XPath queries.
      NameTable nt = new NameTable();
      XmlNamespaceManager nsManager = new XmlNamespaceManager(nt);
      nsManager.AddNamespace("p", presentationmlNamespace);

      foreach (SlidePart slidePart in pptDoc.PresentationPart.SlideParts)
      {
         XmlDocument slideDoc = new XmlDocument(nt);
         slideDoc.Load(slidePart.GetStream());
         XmlNode titleNode = slideDoc.SelectSingleNode("//p:sp//p:ph[@type='title' or @type='ctrTitle']", nsManager);

         if (titleNode != null)
         {
             titles.Add(titleNode.ParentNode.ParentNode.ParentNode.InnerText);
         }
      }
   }
   return titles;
}

Public Function PPTDeleteSlide(ByVal fileName As String, ByVal title As String) As Boolean
   Const presentationmlNamespace As String = "http://schemas.openxmlformats.org/presentationml/2006/main"
   Const relationshipNamespace As String = "http://schemas.openxmlformats.org/officeDocument/2006/relationships"
   Dim returnValue As Boolean = False
   Dim pptDoc As PresentationDocument = PresentationDocument.Open(fileName, True)
   '  Manage namespaces to perform Xml XPath queries.
   Dim nt As NameTable = New NameTable
   Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(nt)
   nsManager.AddNamespace("p", presentationmlNamespace)
   nsManager.AddNamespace("rel", relationshipNamespace)
   Dim xDoc As XmlDocument = New XmlDocument(nt)
   xDoc.Load(pptDoc.PresentationPart.GetStream)
   Dim partToDelete As SlidePart = Nothing
   Dim partId As String = Nothing
   For Each slidePart As SlidePart In pptDoc.PresentationPart.SlideParts
      Dim slideDoc As XmlDocument = New XmlDocument(nt)
      slideDoc.Load(slidePart.GetStream)
      Dim titleNode As XmlNode = slideDoc.SelectSingleNode("//p:sp//p:ph[@type='title' or @type='ctrTitle']", nsManager)
      If (Not (titleNode) Is Nothing) Then
         Dim titleText As String = titleNode.ParentNode.ParentNode.ParentNode.InnerText
         If (String.Compare(titleText, title, True) = 0) Then
            partToDelete = slidePart
            partId = pptDoc.PresentationPart.GetIdOfPart(slidePart)
         End If
      End If
   Next
   If (Not (partToDelete) Is Nothing) Then
      pptDoc.PresentationPart.DeletePart(partToDelete)
      Dim searchString As String = String.Format("//p:sldId[@rel:id='{0}']", partId)
      Dim slideRelNode As XmlNode = xDoc.SelectSingleNode(searchString, nsManager)
      If (Not (slideRelNode) Is Nothing) Then
         slideRelNode.ParentNode.RemoveChild(slideRelNode)
      End If
      xDoc.Save(pptDoc.PresentationPart.GetStream(FileMode.Create))
      returnValue = True
   End If
   Return returnValue
End Function

public static bool PPTDeleteSlide(string fileName, string title)
{
   const string presentationmlNamespace = "http://schemas.openxmlformats.org/presentationml/2006/main";
   const string relationshipNamespace = "http://schemas.openxmlformats.org/officeDocument/2006/relationships";

   bool returnValue = false;

   using (PresentationDocument pptDoc = PresentationDocument.Open(fileName, true))
   {
      //  Manage namespaces to perform Xml XPath queries.
      NameTable nt = new NameTable();
      XmlNamespaceManager nsManager = new XmlNamespaceManager(nt);
      nsManager.AddNamespace("p", presentationmlNamespace);
      nsManager.AddNamespace("rel", relationshipNamespace);
      XmlDocument xDoc = new XmlDocument(nt);
      xDoc.Load(pptDoc.PresentationPart.GetStream());

      SlidePart partToDelete = null;
      string partId = null;
      foreach (SlidePart slidePart in pptDoc.PresentationPart.SlideParts)
      {
         XmlDocument slideDoc = new XmlDocument(nt);
         slideDoc.Load(slidePart.GetStream());
         XmlNode titleNode = slideDoc.SelectSingleNode("//p:sp//p:ph[@type='title' or @type='ctrTitle']", nsManager);
         if (titleNode != null)
         {
            string titleText = titleNode.ParentNode.ParentNode.ParentNode.InnerText;
            if (string.Compare(titleText, title, true) == 0)
            {
               partToDelete = slidePart;
               partId = pptDoc.PresentationPart.GetIdOfPart(slidePart);
               break;
             }
          }
        }
        if (partToDelete != null)
        {
           pptDoc.PresentationPart.DeletePart(partToDelete);
           string searchString = string.Format("//p:sldId[@rel:id='{0}']", partId);
           XmlNode slideRelNode = xDoc.SelectSingleNode(searchString, nsManager);
           if (slideRelNode != null)
           {
              slideRelNode.ParentNode.RemoveChild(slideRelNode);
           }
           xDoc.Save(pptDoc.PresentationPart.GetStream(FileMode.Create));
           returnValue = true;
      }
   }
   return returnValue;
}

Public
Function PPTGetSlideCount(ByVal fileName As
String) As
Integer
Dim returnValue As
Integer = 0
   Dim pptDoc As PresentationDocument = PresentationDocument.Open(fileName, False)
   Using (pptDoc)
      returnValue = pptDoc.PresentationPart.GetPartsCountOfType(Of SlidePart)()
   End Using
   Return returnValue
End
Function

public
static
int PPTGetSlideCount(string fileName)
{
   int returnValue = 0;
   using (PresentationDocument pptDoc = PresentationDocument.Open(fileName, false))
   {
      returnValue = pptDoc.PresentationPart.GetPartsCountOfType<SlidePart>();
   }
   return returnValue;
}

Public Function PPTModifySlideTitle(ByVal fileName As String, ByVal oldSlideTitle As String, ByVal newSlideTitle As String) As Boolean
   Const presentationmlNamespace As String = "http://schemas.openxmlformats.org/presentationml/2006/main"
   Const drawingmlNamespace As String = "http://schemas.openxmlformats.org/drawingml/2006/main"
   Dim returnValue As Boolean = False
   Dim pptPackage As PresentationDocument = PresentationDocument.Open(fileName, True)
   Dim presentationPart As PresentationPart = pptPackage.PresentationPart
   Dim slideParts As IEnumerable = presentationPart.SlideParts
   '  Manage namespaces to perform Xml XPath queries.
   Dim nt As NameTable = New NameTable
   Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(nt)
   nsManager.AddNamespace("p", presentationmlNamespace)
   nsManager.AddNamespace("a", drawingmlNamespace)
   For Each slidePart As SlidePart In slideParts
      Dim doc As XmlDocument = New XmlDocument(nt)
      doc.Load(slidePart.GetStream)
      Dim xNode As XmlNode = doc.SelectSingleNode("//a:t", nsManager)
      If (Not (xNode) Is Nothing) Then
         If (String.Compare(xNode.InnerText, oldSlideTitle, True) = 0) Then
            xNode.InnerText = newSlideTitle
            doc.Save(slidePart.GetStream)
            'pptPackage.Save();
            returnValue = True
         End If
      End If
   Next
   Return returnValue
End Function

public static bool PPTModifySlideTitle(string fileName, string oldSlideTitle, string newSlideTitle)
{
   const string presentationmlNamespace = "http://schemas.openxmlformats.org/presentationml/2006/main";
   const string drawingmlNamespace = "http://schemas.openxmlformats.org/drawingml/2006/main";

   bool returnValue = false;

   using (PresentationDocument pptPackage = PresentationDocument.Open(fileName, true))
   {
      PresentationPart presentationPart = pptPackage.PresentationPart;

      IEnumerable<SlidePart> slideParts = presentationPart.SlideParts;

      //  Manage namespaces to perform Xml XPath queries.
      NameTable nt = new NameTable();
      XmlNamespaceManager nsManager = new XmlNamespaceManager(nt);
      nsManager.AddNamespace("p", presentationmlNamespace);
      nsManager.AddNamespace("a", drawingmlNamespace);

      foreach (SlidePart slidePart in slideParts)
      {
         XmlDocument doc = new XmlDocument(nt);
         doc.Load(slidePart.GetStream());

         XmlNode xNode = doc.SelectSingleNode("//a:t", nsManager);
         if (xNode != null)
         {
            if (string.Compare(xNode.InnerText, oldSlideTitle, true) == 0)
            {
                xNode.InnerText = newSlideTitle;

                doc.Save(slidePart.GetStream());
                //pptPackage.Save();
                returnValue = true;
                break;
            }
         }
      }
   }
   return returnValue;
}

Public Function PPTReorderSlides(ByVal fileName As String, ByVal originalPosition As Integer, ByVal newPosition As Integer) As Integer
   Const presentationmlNamespace As String = "http://schemas.openxmlformats.org/presentationml/2006/main"
   Dim returnValue As Integer = -1
   Dim pptPackage As PresentationDocument = PresentationDocument.Open(fileName, True)
   Dim presentationPart As PresentationPart = pptPackage.PresentationPart
   If (Not (presentationPart) Is Nothing) Then
      Dim doc As XmlDocument = New XmlDocument
      doc.Load(presentationPart.GetStream)
      '  Manage namespaces to perform XPath queries.
      Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(doc.NameTable)
      nsManager.AddNamespace("p", presentationmlNamespace)
      Dim nodes As XmlNodeList = doc.SelectNodes("//p:sldId", nsManager)
      If (Not (nodes) Is Nothing) Then
         Dim slideCount As Integer = nodes.Count
         Dim maxPosition As Integer = slideCount
         If (slideCount > 0) Then
            If (originalPosition = -1) Then
               originalPosition = maxPosition
         End If
         If (newPosition = -1) Then
            newPosition = maxPosition
         End If
         If (originalPosition > maxPosition) Then
            originalPosition = maxPosition
         End If
         If (newPosition > maxPosition) Then
            newPosition = maxPosition
         End If
         If ((originalPosition < 0) OrElse (newPosition < 0)) Then
            '  Something is wrong. Raise an exception.
            Throw New ArgumentException("Invalid parameter. Both original and new positions must be integers between -1 and the total number of slides.")
         End If
         If (originalPosition <> newPosition) Then
            Dim parentNode As XmlNode = doc.SelectSingleNode("//p:sldIdLst", nsManager)
              If (Not (parentNode) Is Nothing) Then
                 '  Get references to both slide nodes.
                 Dim originalNode As XmlNode = Nothing
                 Dim newNode As XmlNode = Nothing
                 Dim nodeSearch As String = Nothing
                 Dim attr As XmlAttribute = nodes((originalPosition - 1)).Attributes("id")
                 If (Not (attr) Is Nothing) Then
                    nodeSearch = String.Format("./p:sldId[@id='{0}']", attr.Value)
                    originalNode = parentNode.SelectSingleNode(nodeSearch, nsManager)
                 End If
                 attr = nodes((newPosition - 1)).Attributes("id")
                 If (Not (attr) Is Nothing) Then
                     nodeSearch = String.Format("./p:sldId[@id='{0}']", attr.Value)
                     newNode = parentNode.SelectSingleNode(nodeSearch, nsManager)
                  End If
                  If ((Not (originalNode) Is Nothing) AndAlso (Not (newNode) Is Nothing)) Then
                     If (newPosition > originalPosition) Then
                        parentNode.InsertAfter(originalNode, newNode)
                     Else
                        parentNode.InsertBefore(originalNode, newNode)
                     End If
                     returnValue = newPosition
                     '  Save the presentation XML back to its part.
                     doc.Save(presentationPart.GetStream)
                  End If
               End If
            End If
         End If
       End If
   End If
   Return returnValue
End Function

public static int PPTReorderSlides(string fileName, int originalPosition, int newPosition)
{
   const string presentationmlNamespace = "http://schemas.openxmlformats.org/presentationml/2006/main";

   int returnValue = -1;

   using (PresentationDocument pptPackage = PresentationDocument.Open(fileName, true))
   {
      PresentationPart presentationPart = pptPackage.PresentationPart;

      if (presentationPart != null)
      {
         XmlDocument doc = new XmlDocument();
         doc.Load(presentationPart.GetStream());

         //  Manage namespaces to perform XPath queries.
         XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);
         nsManager.AddNamespace("p", presentationmlNamespace);

         XmlNodeList nodes = doc.SelectNodes("//p:sldId", nsManager);
         if (nodes != null)
         {
            int slideCount = nodes.Count;
            int maxPosition = slideCount;
            if (slideCount > 0)
            {
               if (originalPosition == -1)
               {
                  originalPosition = maxPosition;
               }
               if (newPosition == -1)
               {
                  newPosition = maxPosition;
               }
               if (originalPosition > maxPosition)
               {
                  originalPosition = maxPosition;
               }
               if (newPosition > maxPosition)
               {
                  newPosition = maxPosition;
               }
               if (originalPosition < 0 || newPosition < 0)
               {
                  //  Something is wrong. Raise an exception.
                  throw new ArgumentException("Invalid parameter. Both original and new positions must be integers between -1 and the total number of slides.");
                }

                if (originalPosition != newPosition)
                {
                   XmlNode parentNode = doc.SelectSingleNode("//p:sldIdLst", nsManager);
                   if (parentNode != null)
                   {
                      XmlNode originalNode = null;
                      XmlNode newNode = null;
                      string nodeSearch = null;

                      XmlAttribute attr = nodes[originalPosition - 1].Attributes["id"];
                      if (attr != null)
                      {
                         nodeSearch = string.Format("./p:sldId[@id='{0}']", attr.Value);
                         originalNode = parentNode.SelectSingleNode(nodeSearch, nsManager);
                      }
                      attr = nodes[newPosition - 1].Attributes["id"];
                      if (attr != null)
                      {
                          nodeSearch = string.Format("./p:sldId[@id='{0}']", attr.Value);
                          newNode = parentNode.SelectSingleNode(nodeSearch, nsManager);
                      }
                      if (originalNode != null && newNode != null)
                      {
                         if (newPosition > originalPosition)
                         {
                            parentNode.InsertAfter(originalNode, newNode);
                         }
                         else
                         {
                            parentNode.InsertBefore(originalNode, newNode);
                         }
                         returnValue = newPosition;

                        doc.Save(presentationPart.GetStream());
                      }
                   }
                }
            }
         }
      }
   }
   return returnValue;
}

Public Sub PPTReplaceImageOnSlide(ByVal fileName As String, ByVal slideTitle As String, ByVal imagePath As String)
   Const presentationmlNamespace As String = "http://schemas.openxmlformats.org/presentationml/2006/main"
   Const drawingmlNamespace As String = "http://schemas.openxmlformats.org/drawingml/2006/main"
   Const relationshipNamespace As String = "http://schemas.openxmlformats.org/officeDocument/2006/relationships"
   Dim pptPackage As PresentationDocument = PresentationDocument.Open(fileName, True)
   Using (pptPackage)
      Dim presentationPart As PresentationPart = pptPackage.PresentationPart
      '  Manage namespaces to perform Xml XPath queries.
      Dim nt As NameTable = New NameTable
      Dim nsManager As XmlNamespaceManager = New XmlNamespaceManager(nt)
      nsManager.AddNamespace("p", presentationmlNamespace)
      nsManager.AddNamespace("a", drawingmlNamespace)
      nsManager.AddNamespace("r", relationshipNamespace)
      Dim slideParts As List(Of SlidePart) = New List(Of SlidePart)()
      presentationPart.GetPartsOfType(Of SlidePart)(slideParts)
      For Each slidePart As SlidePart In slideParts
         Dim slideDoc As XmlDocument = New XmlDocument(nt)
         slideDoc.Load(slidePart.GetStream)
         Dim titleNode As XmlNode = slideDoc.SelectSingleNode("//p:sp//p:ph[@type='title' or @type='ctrTitle']", nsManager)
         If (Not (titleNode) Is Nothing) Then
            Dim titleText As String = titleNode.ParentNode.ParentNode.ParentNode.InnerText
             If (String.Compare(titleText, slideTitle, True) = 0) Then
               Dim imageParts As List(Of ImagePart) = New List(Of ImagePart)()
               slidePart.GetPartsOfType(Of ImagePart)(imageParts)
               For Each imagePart As ImagePart In imageParts
                  If (Not (imagePart) Is Nothing) Then
                     Dim oldRelID As String = slidePart.GetIdOfPart(imagePart)
                    Dim imageFile As String = Path.GetFileName(imagePath)
                    Dim newImageUri As Uri = New Uri(("/ppt/media/" + imageFile), UriKind.Relative)
                    Dim newImagePart As ImagePart = slidePart.AddImagePart(ImagePartType.Jpeg)
                    Dim outputStream As Stream = newImagePart.GetStream
                    Dim inputStream As FileStream = New FileStream(imagePath, FileMode.Open, FileAccess.Read)
                    Dim len As Integer = Convert.ToInt32(inputStream.Length)
                    Dim bytes() As Byte = New Byte((len) - 1) {}
                    Dim bytesRead As Integer = inputStream.Read(bytes, 0, len)
                    If (bytesRead = len) Then
                       outputStream.Write(bytes, 0, len)
                    End If
                    Dim searchString As String = String.Format("//p:pic//a:blip[@r:embed='{0}']", oldRelID)
                    Dim relNode As XmlNode = slideDoc.SelectSingleNode(searchString, nsManager)
                    If (Not (relNode) Is Nothing) Then
                       relNode.Attributes("r:embed").Value = slidePart.GetIdOfPart(newImagePart)
                    End If
                    slidePart.DeletePart(imagePart)

                   End If
               Next
               '  Reset the stream, and save the slide XML back to its part.
               slideDoc.Save(slidePart.GetStream)

            End If
         End If
      Next
   End Using
End Sub

public static void PPTReplaceImageOnSlide(string fileName, string slideTitle, string imagePath)
{
   const string presentationmlNamespace = "http://schemas.openxmlformats.org/presentationml/2006/main";
   const string drawingmlNamespace = "http://schemas.openxmlformats.org/drawingml/2006/main";
   const string relationshipNamespace = "http://schemas.openxmlformats.org/officeDocument/2006/relationships";

   using (PresentationDocument pptPackage = PresentationDocument.Open(fileName, true))
   {
      PresentationPart presentationPart = pptPackage.PresentationPart;

      //  Manage namespaces to perform Xml XPath queries.
      NameTable nt = new NameTable();
      XmlNamespaceManager nsManager = new XmlNamespaceManager(nt);
      nsManager.AddNamespace("p", presentationmlNamespace);
      nsManager.AddNamespace("a", drawingmlNamespace);
      nsManager.AddNamespace("r", relationshipNamespace);

      List<SlidePart> slideParts = new List<SlidePart>();
      presentationPart.GetPartsOfType<SlidePart>(slideParts);

      foreach (SlidePart slidePart in slideParts)
      {
         XmlDocument slideDoc = new XmlDocument(nt);
         slideDoc.Load(slidePart.GetStream());

         XmlNode titleNode = slideDoc.SelectSingleNode("//p:sp//p:ph[@type='title' or @type='ctrTitle']", nsManager);
         if (titleNode != null)
         {
            string titleText = titleNode.ParentNode.ParentNode.ParentNode.InnerText;

            if (string.Compare(titleText, slideTitle, true) == 0)
            {
               List<ImagePart> imageParts = new List<ImagePart>();

               slidePart.GetPartsOfType<ImagePart>(imageParts);
               foreach (ImagePart imagePart in imageParts)
               {
                  if (imagePart != null)
                  {
                     string oldRelID = slidePart.GetIdOfPart(imagePart);
                     string imageFile = Path.GetFileName(imagePath);
                     Uri newImageUri = new Uri("/ppt/media/" + imageFile, UriKind.Relative);
                     ImagePart newImagePart = slidePart.AddImagePart(ImagePartType.Jpeg);

                     using (Stream outputStream = newImagePart.GetStream())
                     {
                        using (FileStream inputStream = new FileStream(imagePath, FileMode.Open, FileAccess.Read))
                        {
                           int len = Convert.ToInt32(inputStream.Length);
                           byte[] bytes = new byte[len];
                           int bytesRead = inputStream.Read(bytes, 0, len);
                           if (bytesRead == len)
                           {
                              outputStream.Write(bytes, 0, len);
                           }
                        }
                        }
                        string searchString = string.Format("//p:pic//a:blip[@r:embed='{0}']", oldRelID);
                        XmlNode relNode = slideDoc.SelectSingleNode(searchString, nsManager);
                        if (relNode != null)
                        {
                           relNode.Attributes["r:embed"].Value = slidePart.GetIdOfPart(newImagePart);
                        }
                        slidePart.DeletePart(imagePart);
                        break;
                  }
               }

              slideDoc.Save(slidePart.GetStream());
               break;
            }
         }
      }
   }
}