Remove code that required C# 7.0

Author: EricWhiteDev

OpenXmlPowerTools/DocumentBuilder.cs

@@ -1172,9 +1172,10 @@ private static void AddSectionAndDependencies(WordprocessingDocument sourceDocum
  {
  string oldRid = footerReference.Attribute(R.id).Value;
  var oldFooterPart2 = sourceDocument.MainDocumentPart.GetPartById(oldRid);
- if (!(oldFooterPart2 is FooterPart oldFooterPart))
+ if (!(oldFooterPart2 is FooterPart))
  throw new DocumentBuilderException("Invalid document - invalid footer part.");
 
+ FooterPart oldFooterPart = (FooterPart)oldFooterPart2;
  XDocument oldFooterXDoc = oldFooterPart.GetXDocument();
  if (oldFooterXDoc != null && oldFooterXDoc.Root != null)
  CopyNumbering(sourceDocument, newDocument, new[] { oldFooterXDoc.Root }, images);
@@ -1579,13 +1580,15 @@ private static void CopyComments(WordprocessingDocument sourceDocument, Wordproc
  newComments.Add(new XElement(W.comments, NamespaceAttributes));
  }
  }
- if (!int.TryParse((string)comment.Attribute(W.id), out int id))
+ int id;
+ if (!int.TryParse((string)comment.Attribute(W.id), out id))
  throw new DocumentBuilderException("Invalid document - invalid comment id");
  XElement element = oldComments
  .Descendants()
  .Elements(W.comment)
  .Where(p => {
- if (! int.TryParse((string)p.Attribute(W.id), out int thisId))
+ int thisId;
+ if (! int.TryParse((string)p.Attribute(W.id), out thisId))
  throw new DocumentBuilderException("Invalid document - invalid comment id");
  return thisId == id;
  })
@@ -1633,7 +1636,8 @@ private static void AdjustUniqueIds(WordprocessingDocument sourceDocument,
  foreach (var item in newContent.DescendantsAndSelf().Where(bm => bm.Name == W.bookmarkStart ||
  bm.Name == W.bookmarkEnd))
  {
- if (!int.TryParse((string)item.Attribute(W.id), out int id))
+ int id;
+ if (!int.TryParse((string)item.Attribute(W.id), out id))
  throw new DocumentBuilderException("Invalid document - invalid value for bookmark ID");
  if (!bookmarkIdMap.ContainsKey(id))
  bookmarkIdMap.Add(id, ++maxId);
@@ -2268,7 +2272,8 @@ private static void CopyNumbering(WordprocessingDocument sourceDocument, Wordpro
  .Elements(W.abstractNumId)
  .First()
  .Attribute(W.val);
- if (!int.TryParse(abstractNumIdStr, out int abstractNumId))
+ int abstractNumId;
+ if (!int.TryParse(abstractNumIdStr, out abstractNumId))
  throw new DocumentBuilderException("Invalid document - invalid value for abstractNumId");
 
  XElement abstractElement = oldNumbering
@@ -2429,7 +2434,8 @@ private static void CopyNumberingForGlossaryDocumentPartFromGD(NumberingDefiniti
  .Elements(W.abstractNumId)
  .First()
  .Attribute(W.val);
- if (!int.TryParse(abstractNumIdStr, out int abstractNumId))
+ int abstractNumId;
+ if (!int.TryParse(abstractNumIdStr, out abstractNumId))
  throw new DocumentBuilderException("Invalid document - invalid value for abstractNumId");
  XElement abstractElement = oldNumbering
  .Descendants()
@@ -2590,7 +2596,8 @@ private static void CopyNumberingForGlossaryDocumentPartToGD(NumberingDefinition
  .Elements(W.abstractNumId)
  .First()
  .Attribute(W.val);
- if (!int.TryParse(abstractNumIdStr, out int abstractNumId))
+ int abstractNumId;
+ if (!int.TryParse(abstractNumIdStr, out abstractNumId))
  throw new DocumentBuilderException("Invalid document - invalid value for abstractNumId");
  XElement abstractElement = oldNumbering
  .Descendants()