Fix nullable references

samples/presentation/add_comment/cs/Program.cs

@@ -100,14 +100,14 @@ static SlidePart GetFirstSlide(PresentationDocument? presentationDocument)
     string? relId = slideId?.RelationshipId;
     if (relId is null)
     {
-        throw new NullReferenceException("The first slide does not contain a relationship ID.");
+        throw new ArgumentNullException("The first slide does not contain a relationship ID.");
     }
     // Get the slide part by the relationship ID.
     SlidePart? slidePart = part?.GetPartById(relId) as SlidePart;
 
     if (slidePart is null)
     {
-        throw new NullReferenceException("The slide part is null.");
+        throw new ArgumentNullException("The slide part is null.");
     }
 
     return slidePart;

samples/word/accept_all_revisions/cs/Program.cs

@@ -1,6 +1,7 @@
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -12,7 +13,7 @@ static void AcceptAllRevisions(string fileName, string authorName)
     {
         if (wdDoc.MainDocumentPart is null || wdDoc.MainDocumentPart.Document.Body is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         Body body = wdDoc.MainDocumentPart.Document.Body;
@@ -66,7 +67,7 @@ static void AcceptAllRevisions(string fileName, string authorName)
                 }
                 else
                 {
-                    OpenXmlElement? nextSibling = insertion.NextSibling() ?? throw new System.NullReferenceException("NextSibling is null.");
+                    OpenXmlElement? nextSibling = insertion.NextSibling() ?? throw new ArgumentNullException("NextSibling is null.");
                     nextSibling.InsertAfterSelf(new Run(run.OuterXml));
                 }
             }

samples/word/add_tables/cs/Program.cs

@@ -1,6 +1,7 @@
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 
 AddTable(args[0], args[1]);
 
@@ -17,7 +18,7 @@ static void AddTable(string fileName, string json)
         {
             if (document.MainDocumentPart is null || document.MainDocumentPart.Document.Body is null)
             {
-                throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+                throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
             }
 
             var doc = document.MainDocumentPart.Document;

samples/word/change_text_a_table/cs/Program.cs

@@ -1,5 +1,6 @@
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 using System.Linq;
 
 ChangeTextInCell(args[0], args[1]);
@@ -13,7 +14,7 @@ static void ChangeTextInCell(string filePath, string txt)
     {
         if (doc.MainDocumentPart is null || doc.MainDocumentPart.Document.Body is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         // Find the first table in the document.

samples/word/change_the_print_orientation/cs/Program.cs

@@ -3,6 +3,7 @@
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 using System.Linq;
 
 SetPrintOrientation(args[0], args[1]);
@@ -25,7 +26,7 @@ static void SetPrintOrientation(string fileName, string no)
 
         if (document.MainDocumentPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         var docPart = document.MainDocumentPart;
@@ -37,7 +38,7 @@ static void SetPrintOrientation(string fileName, string no)
         {
             bool pageOrientationChanged = false;
 
-            PageSize pgSz = (sectPr.Descendants<PageSize>().FirstOrDefault()) ?? throw new System.NullReferenceException("There are no PageSize elements in the section.");
+            PageSize pgSz = (sectPr.Descendants<PageSize>().FirstOrDefault()) ?? throw new ArgumentNullException("There are no PageSize elements in the section.");
             if (pgSz != null)
             {
                 // No Orient property? Create it now. Otherwise, just 
@@ -78,7 +79,7 @@ static void SetPrintOrientation(string fileName, string no)
                     pgSz.Width = height;
                     pgSz.Height = width;
 
-                    PageMargin pgMar = (sectPr.Descendants<PageMargin>().FirstOrDefault()) ?? throw new System.NullReferenceException("There are no PageMargin elements in the section.");
+                    PageMargin pgMar = (sectPr.Descendants<PageMargin>().FirstOrDefault()) ?? throw new ArgumentNullException("There are no PageMargin elements in the section.");
 
                     if (pgMar != null)
                     {
@@ -89,7 +90,7 @@ static void SetPrintOrientation(string fileName, string no)
                         // procedure.
                         if (pgMar.Top is null || pgMar.Bottom is null || pgMar.Left is null || pgMar.Right is null)
                         {
-                            throw new System.NullReferenceException("One or more of the PageMargin elements is null.");
+                            throw new ArgumentNullException("One or more of the PageMargin elements is null.");
                         }
 
                         var top = pgMar.Top.Value;

samples/word/convert_from_the_docm_to_the_docx_file_format/cs/Program.cs

@@ -1,5 +1,6 @@
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
+using System;
 using System.IO;
 
 ConvertDOCMtoDOCX(args[0]);
@@ -13,7 +14,7 @@ static void ConvertDOCMtoDOCX(string fileName)
     using (WordprocessingDocument document = WordprocessingDocument.Open(fileName, true))
     {
         // Access the main document part.
-        var docPart = document.MainDocumentPart ?? throw new System.NullReferenceException("MainDocumentPart is null.");
+        var docPart = document.MainDocumentPart ?? throw new ArgumentNullException("MainDocumentPart is null.");
 
         // Look for the vbaProject part. If it is there, delete it.
         var vbaPart = docPart.VbaProjectPart;

samples/word/create_and_add_a_character_style/cs/Program.cs

@@ -1,5 +1,6 @@
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 
 CreateAndAddCharacterStyle(args[0], args[1], args[2], args[3]);
 
@@ -61,7 +62,7 @@ static StyleDefinitionsPart AddStylesPartToPackage(WordprocessingDocument? doc)
 
     if (doc?.MainDocumentPart is null)
     {
-        throw new System.NullReferenceException("MainDocumentPart is null.");
+        throw new ArgumentNullException("MainDocumentPart is null.");
     }
 
     part = doc.MainDocumentPart.AddNewPart<StyleDefinitionsPart>();

samples/word/create_and_add_a_paragraph_style/cs/Program.cs

@@ -1,5 +1,6 @@
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 
 CreateAndAddParagraphStyle(args[0], args[1], args[2], args[3]);
 
@@ -81,7 +82,7 @@ static StyleDefinitionsPart AddStylesPartToPackage(WordprocessingDocument? doc)
 
     if (doc?.MainDocumentPart is null)
     {
-        throw new System.NullReferenceException("MainDocumentPart is null.");
+        throw new ArgumentNullException("MainDocumentPart is null.");
     }
 
     part = doc.MainDocumentPart.AddNewPart<StyleDefinitionsPart>();

samples/word/delete_comments_by_all_or_a_specific_author/cs/Program.cs

@@ -16,7 +16,7 @@ static void DeleteComments(string fileName, string author = "")
 
         if (document.MainDocumentPart is null || document.MainDocumentPart.WordprocessingCommentsPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or WordprocessingCommentsPart is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or WordprocessingCommentsPart is null.");
         }
 
         // Set commentPart to the document WordprocessingCommentsPart, 

samples/word/extract_styles/cs/Program.cs

@@ -1,4 +1,5 @@
 using DocumentFormat.OpenXml.Packaging;
+using System;
 using System.IO;
 using System.Xml;
 using System.Xml.Linq;
@@ -24,7 +25,7 @@ static XDocument ExtractStylesPart(string fileName, string getStylesWithEffectsP
     {
         if (document.MainDocumentPart is null || document.MainDocumentPart.StyleDefinitionsPart is null || document.MainDocumentPart.StylesWithEffectsPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or one or both of the Styles parts is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or one or both of the Styles parts is null.");
         }
 
         // Get a reference to the main document part.

samples/word/insert_a_comment/cs/Program.cs

@@ -14,7 +14,7 @@ static void AddCommentOnFirstParagraph(string fileName, string author, string in
     {
         if (document.MainDocumentPart is null/* || document.MainDocumentPart.WordprocessingCommentsPart is null*/)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         WordprocessingCommentsPart wordprocessingCommentsPart = document.MainDocumentPart.WordprocessingCommentsPart ?? document.MainDocumentPart.AddNewPart<WordprocessingCommentsPart>();
@@ -39,7 +39,7 @@ static void AddCommentOnFirstParagraph(string fileName, string author, string in
                     }
                     else 
                     { 
-                        throw new System.NullReferenceException("Comment id and/or value are null."); 
+                        throw new ArgumentNullException("Comment id and/or value are null."); 
                     }
                 })
                     .Max() + 1).ToString();

samples/word/insert_a_picture/cs/Program.cs

@@ -1,6 +1,7 @@
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 using System.IO;
 using A = DocumentFormat.OpenXml.Drawing;
 using DW = DocumentFormat.OpenXml.Drawing.Wordprocessing;
@@ -14,7 +15,7 @@ static void InsertAPicture(string document, string fileName)
     {
         if (wordprocessingDocument.MainDocumentPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart is null.");
+            throw new ArgumentNullException("MainDocumentPart is null.");
         }
 
         MainDocumentPart mainPart = wordprocessingDocument.MainDocumentPart;
@@ -98,7 +99,7 @@ static void AddImageToBody(WordprocessingDocument wordDoc, string relationshipId
 
     if (wordDoc.MainDocumentPart is null || wordDoc.MainDocumentPart.Document.Body is null)
     {
-        throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+        throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
     }
 
     // Append the reference to body, the element should be in a Run.

samples/word/insert_a_table/cs/Program.cs

@@ -1,6 +1,7 @@
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 
 CreateTable(args[0]);
 
@@ -88,7 +89,7 @@ static void CreateTable(string fileName)
 
         if (doc.MainDocumentPart is null || doc.MainDocumentPart.Document.Body is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         // Append the table to the document.

samples/word/remove_hidden_text/cs/Program.cs

@@ -1,4 +1,5 @@
 using DocumentFormat.OpenXml.Packaging;
+using System;
 using System.IO;
 using System.Xml;
 
@@ -18,7 +19,7 @@ static void WDDeleteHiddenText(string docName)
 
         if (wdDoc.MainDocumentPart is null || wdDoc.MainDocumentPart.Document.Body is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         // Get the document part from the package.

samples/word/remove_the_headers_and_footers/cs/Program.cs

@@ -1,5 +1,6 @@
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 using System.Linq;
 
 RemoveHeadersAndFooters(args[0]);
@@ -13,7 +14,7 @@ static void RemoveHeadersAndFooters(string filename)
     {
         if (doc.MainDocumentPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart is null.");
+            throw new ArgumentNullException("MainDocumentPart is null.");
         }
 
         // Get a reference to the main document part.

samples/word/replace_the_header/cs/Program.cs

@@ -1,5 +1,6 @@
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Wordprocessing;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -13,12 +14,12 @@ static void AddHeaderFromTo(string filepathFrom, string filepathTo)
     {
         if (wdDocSource.MainDocumentPart is null || wdDocSource.MainDocumentPart.HeaderParts is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or HeaderParts is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or HeaderParts is null.");
         }
 
         if (wdDoc.MainDocumentPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart is null.");
+            throw new ArgumentNullException("MainDocumentPart is null.");
         }
 
         MainDocumentPart mainPart = wdDoc.MainDocumentPart;
@@ -45,7 +46,7 @@ static void AddHeaderFromTo(string filepathFrom, string filepathTo)
 
         if (mainPart.Document.Body is null)
         {
-            throw new System.NullReferenceException("Body is null.");
+            throw new ArgumentNullException("Body is null.");
         }
 
         // Get SectionProperties and Replace HeaderReference with new Id.

samples/word/replace_the_styles_parts/cs/Program.cs

@@ -1,4 +1,5 @@
 using DocumentFormat.OpenXml.Packaging;
+using System;
 using System.IO;
 using System.Xml;
 using System.Xml.Linq;
@@ -33,7 +34,7 @@ static void ReplaceStylesPart(string fileName, XDocument newStyles, bool setStyl
     {
         if (document.MainDocumentPart is null || document.MainDocumentPart.StyleDefinitionsPart is null || document.MainDocumentPart.StylesWithEffectsPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or one or both of the Styles parts is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or one or both of the Styles parts is null.");
         }
 
         // Get a reference to the main document part.
@@ -71,7 +72,7 @@ static XDocument ExtractStylesPart(string fileName, bool getStylesWithEffectsPar
 
         if (docPart is null || docPart.StyleDefinitionsPart is null || docPart.StylesWithEffectsPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or one or both of the Styles parts is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or one or both of the Styles parts is null.");
         }
 
         // Assign a reference to the appropriate part to the

samples/word/replace_the_theme_part/cs/Program.cs

@@ -1,4 +1,5 @@
 using DocumentFormat.OpenXml.Packaging;
+using System;
 using System.IO;
 
 ReplaceTheme(args[0], args[1]);
@@ -10,7 +11,7 @@ static void ReplaceTheme(string document, string themeFile)
     {
         if (wordDoc.MainDocumentPart is null || wordDoc.MainDocumentPart.Document.Body is null || wordDoc.MainDocumentPart.ThemePart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body and/or ThemePart is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body and/or ThemePart is null.");
         }
 
         MainDocumentPart mainPart = wordDoc.MainDocumentPart;

samples/word/retrieve_application_property_values/cs/Program.cs

@@ -9,7 +9,7 @@ static void GetApplicationProperty(string fileName)
     {
         if (document.ExtendedFilePropertiesPart is null)
         {
-            throw new System.NullReferenceException("ExtendedFilePropertiesPart is null.");
+            throw new ArgumentNullException("ExtendedFilePropertiesPart is null.");
         }
 
         var props = document.ExtendedFilePropertiesPart.Properties;

samples/word/retrieve_comments/cs/Program.cs

@@ -10,7 +10,7 @@ static void GetCommentsFromDocument(string fileName)
     {
         if (wordDoc.MainDocumentPart is null || wordDoc.MainDocumentPart.WordprocessingCommentsPart is null)
         {
-            throw new System.InvalidOperationException("MainDocumentPart and/or WordprocessingCommentsPart is null.");
+            throw new System.ArgumentNullException("MainDocumentPart and/or WordprocessingCommentsPart is null.");
         }
 
         WordprocessingCommentsPart commentsPart = wordDoc.MainDocumentPart.WordprocessingCommentsPart;

samples/word/search_and_replace_text_a_part/cs/Program.cs

@@ -1,4 +1,5 @@
 using DocumentFormat.OpenXml.Packaging;
+using System;
 using System.IO;
 using System.Text.RegularExpressions;
 
@@ -14,7 +15,7 @@ static void SearchAndReplace(string document)
 
         if (wordDoc.MainDocumentPart is null)
         {
-            throw new System.NullReferenceException("MainDocumentPart and/or Body is null.");
+            throw new ArgumentNullException("MainDocumentPart and/or Body is null.");
         }
 
         using (StreamReader sr = new StreamReader(wordDoc.MainDocumentPart.GetStream()))