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/presentation/retrieve_the_number_of_slides/cs/Program.cs

@@ -1,37 +1,49 @@
-#nullable disable
-
 using DocumentFormat.OpenXml.Packaging;
 using System;
+using System.IO.Enumeration;
 using System.Linq;
 
-static int RetrieveNumberOfSlides(string fileName,
-    bool includeHidden = true)
+if (args is [ { } fileName, {} includeHidden])
+{
+    RetrieveNumberOfSlides(fileName, includeHidden);
+}
+else if (args is [{ } fileName2])
+{
+    RetrieveNumberOfSlides(fileName2);
+}
+
+static int RetrieveNumberOfSlides(string fileName, string includeHidden = "true")
 {
     int slidesCount = 0;
 
-    using (PresentationDocument doc =
-        PresentationDocument.Open(fileName, false))
+    using (PresentationDocument doc = PresentationDocument.Open(fileName, false))
     {
-        // Get the presentation part of the document.
-        PresentationPart presentationPart = doc.PresentationPart;
-        if (presentationPart != null)
+        if (doc is not null && doc.PresentationPart is not null)
         {
-            if (includeHidden)
+            // Get the presentation part of the document.
+            PresentationPart presentationPart = doc.PresentationPart;
+            if (presentationPart is not null)
             {
-                slidesCount = presentationPart.SlideParts.Count();
-            }
-            else
-            {
-                // Each slide can include a Show property, which if hidden 
-                // will contain the value "0". The Show property may not 
-                // exist, and most likely will not, for non-hidden slides.
-                var slides = presentationPart.SlideParts.Where(
-                    (s) => (s.Slide != null) &&
-                      ((s.Slide.Show == null) || (s.Slide.Show.HasValue &&
-                      s.Slide.Show.Value)));
-                slidesCount = slides.Count();
+                if (includeHidden.ToLower() == "true")
+                {
+                    slidesCount = presentationPart.SlideParts.Count();
+                }
+                else
+                {
+                    // Each slide can include a Show property, which if hidden 
+                    // will contain the value "0". The Show property may not 
+                    // exist, and most likely will not, for non-hidden slides.
+                    var slides = presentationPart.SlideParts.Where(
+                        (s) => (s.Slide is not null) &&
+                          ((s.Slide.Show is null) || (s.Slide.Show.HasValue && s.Slide.Show.Value)));
+
+                    slidesCount = slides.Count();
+                }
             }
         }
     }
+
+    Console.WriteLine($"Slide Count: {slidesCount}");
+
     return slidesCount;
 }

samples/spreadsheet/insert_a_new_worksheet/cs/Program.cs

@@ -1,27 +1,28 @@
-#nullable disable
-
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Spreadsheet;
 using System.Linq;
 
+InsertWorksheet(args[0]);
+
 // Given a document name, inserts a new worksheet.
 static void InsertWorksheet(string docName)
 {
     // Open the document for editing.
     using (SpreadsheetDocument spreadSheet = SpreadsheetDocument.Open(docName, true))
     {
+        WorkbookPart workbookPart = spreadSheet.WorkbookPart ?? spreadSheet.AddWorkbookPart();
         // Add a blank WorksheetPart.
-        WorksheetPart newWorksheetPart = spreadSheet.WorkbookPart.AddNewPart<WorksheetPart>();
+        WorksheetPart newWorksheetPart = workbookPart.AddNewPart<WorksheetPart>();
         newWorksheetPart.Worksheet = new Worksheet(new SheetData());
 
-        Sheets sheets = spreadSheet.WorkbookPart.Workbook.GetFirstChild<Sheets>();
-        string relationshipId = spreadSheet.WorkbookPart.GetIdOfPart(newWorksheetPart);
+        Sheets sheets = workbookPart.Workbook.GetFirstChild<Sheets>() ?? workbookPart.Workbook.AppendChild(new Sheets());
+        string relationshipId = workbookPart.GetIdOfPart(newWorksheetPart);
 
         // Get a unique ID for the new worksheet.
         uint sheetId = 1;
         if (sheets.Elements<Sheet>().Count() > 0)
         {
-            sheetId = sheets.Elements<Sheet>().Select(s => s.SheetId.Value).Max() + 1;
+            sheetId = (sheets.Elements<Sheet>().Select(s => s.SheetId?.Value).Max() + 1) ?? (uint)sheets.Elements<Sheet>().Count() + 1;
         }
 
         // Give the new worksheet a name.

samples/spreadsheet/merge_two_adjacent_cells/cs/Program.cs

@@ -1,5 +1,3 @@
-#nullable disable
-
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Spreadsheet;
@@ -8,6 +6,8 @@
 using System.Linq;
 using System.Text.RegularExpressions;
 
+MergeTwoCells(args[0], args[1], args[2], args[3]);
+
 // Given a document name, a worksheet name, and the names of two adjacent cells, merges the two cells.
 // When two cells are merged, only the content from one cell is preserved:
 // the upper-left cell for left-to-right languages or the upper-right cell for right-to-left languages.
@@ -16,8 +16,8 @@ static void MergeTwoCells(string docName, string sheetName, string cell1Name, st
     // Open the document for editing.
     using (SpreadsheetDocument document = SpreadsheetDocument.Open(docName, true))
     {
-        Worksheet worksheet = GetWorksheet(document, sheetName);
-        if (worksheet == null || string.IsNullOrEmpty(cell1Name) || string.IsNullOrEmpty(cell2Name))
+        Worksheet? worksheet = GetWorksheet(document, sheetName);
+        if (worksheet is null || string.IsNullOrEmpty(cell1Name) || string.IsNullOrEmpty(cell2Name))
         {
             return;
         }
@@ -88,7 +88,7 @@ static void CreateSpreadsheetCellIfNotExist(Worksheet worksheet, string cellName
     string columnName = GetColumnName(cellName);
     uint rowIndex = GetRowIndex(cellName);
 
-    IEnumerable<Row> rows = worksheet.Descendants<Row>().Where(r => r.RowIndex.Value == rowIndex);
+    IEnumerable<Row> rows = worksheet.Descendants<Row>().Where(r => r.RowIndex?.Value == rowIndex);
 
     // If the Worksheet does not contain the specified row, create the specified row.
     // Create the specified cell in that row, and insert the row into the Worksheet.
@@ -98,33 +98,36 @@ static void CreateSpreadsheetCellIfNotExist(Worksheet worksheet, string cellName
         Cell cell = new Cell() { CellReference = new StringValue(cellName) };
         row.Append(cell);
         worksheet.Descendants<SheetData>().First().Append(row);
+
         worksheet.Save();
     }
     else
     {
         Row row = rows.First();
 
-        IEnumerable<Cell> cells = row.Elements<Cell>().Where(c => c.CellReference.Value == cellName);
+        IEnumerable<Cell> cells = row.Elements<Cell>().Where(c => c.CellReference?.Value == cellName);
 
         // If the row does not contain the specified cell, create the specified cell.
         if (cells.Count() == 0)
         {
             Cell cell = new Cell() { CellReference = new StringValue(cellName) };
             row.Append(cell);
+
             worksheet.Save();
         }
     }
 }
 
 // Given a SpreadsheetDocument and a worksheet name, get the specified worksheet.
-static Worksheet GetWorksheet(SpreadsheetDocument document, string worksheetName)
+static Worksheet? GetWorksheet(SpreadsheetDocument document, string worksheetName)
 {
-    IEnumerable<Sheet> sheets = document.WorkbookPart.Workbook.Descendants<Sheet>().Where(s => s.Name == worksheetName);
-    WorksheetPart worksheetPart = (WorksheetPart)document.WorkbookPart.GetPartById(sheets.First().Id);
-    if (sheets.Count() == 0)
-        return null;
-    else
-        return worksheetPart.Worksheet;
+    WorkbookPart workbookPart = document.WorkbookPart ?? document.AddWorkbookPart();
+    IEnumerable<Sheet> sheets = workbookPart.Workbook.Descendants<Sheet>().Where(s => s.Name == worksheetName);
+
+    string? id = sheets.First().Id;
+    WorksheetPart? worksheetPart = id is not null ? (WorksheetPart)workbookPart.GetPartById(id) : null;
+
+    return worksheetPart?.Worksheet;
 }
 
 // Given a cell name, parses the specified cell to get the column name.

samples/spreadsheet/open_for_read_only_access/cs/Program.cs

@@ -1,15 +1,17 @@
-#nullable disable
 using DocumentFormat.OpenXml.Packaging;
 
 static void OpenSpreadsheetDocumentReadonly(string filepath)
 {
     // Open a SpreadsheetDocument based on a filepath.
     using (SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(filepath, false))
     {
-        // Attempt to add a new WorksheetPart.
-        // The call to AddNewPart generates an exception because the file is read-only.
-        WorksheetPart newWorksheetPart = spreadsheetDocument.WorkbookPart.AddNewPart<WorksheetPart>();
+        if (spreadsheetDocument.WorkbookPart is not null)
+        {
+            // Attempt to add a new WorksheetPart.
+            // The call to AddNewPart generates an exception because the file is read-only.
+            WorksheetPart newWorksheetPart = spreadsheetDocument.WorkbookPart.AddNewPart<WorksheetPart>();
 
-        // The rest of the code will not be called.
+            // The rest of the code will not be called.
+        }
     }
 }

samples/spreadsheet/open_from_a_stream/cs/Program.cs

@@ -1,39 +1,53 @@
-#nullable disable
-
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Spreadsheet;
 using System.IO;
 using System.Linq;
 
+FileStream fileStream = new(args[0], FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
+OpenAndAddToSpreadsheetStream(fileStream);
+
 static void OpenAndAddToSpreadsheetStream(Stream stream)
 {
     // Open a SpreadsheetDocument based on a stream.
-    SpreadsheetDocument spreadsheetDocument =
-        SpreadsheetDocument.Open(stream, true);
+    SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(stream, true);
 
-    // Add a new worksheet.
-    WorksheetPart newWorksheetPart = spreadsheetDocument.WorkbookPart.AddNewPart<WorksheetPart>();
-    newWorksheetPart.Worksheet = new Worksheet(new SheetData());
-    newWorksheetPart.Worksheet.Save();
+    if (spreadsheetDocument is not null)
+    {
+        // Get or create the WorkbookPart
+        WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart ?? spreadsheetDocument.AddWorkbookPart();
 
-    Sheets sheets = spreadsheetDocument.WorkbookPart.Workbook.GetFirstChild<Sheets>();
-    string relationshipId = spreadsheetDocument.WorkbookPart.GetIdOfPart(newWorksheetPart);
+        // Add a new worksheet.
+        WorksheetPart newWorksheetPart = workbookPart.AddNewPart<WorksheetPart>();
+        newWorksheetPart.Worksheet = new Worksheet(new SheetData());
+        newWorksheetPart.Worksheet.Save();
 
-    // Get a unique ID for the new worksheet.
-    uint sheetId = 1;
-    if (sheets.Elements<Sheet>().Count() > 0)
-    {
-        sheetId = sheets.Elements<Sheet>().Select(s => s.SheetId.Value).Max() + 1;
-    }
+        Workbook workbook = workbookPart.Workbook ?? new Workbook();
 
-    // Give the new worksheet a name.
-    string sheetName = "Sheet" + sheetId;
+        if (workbookPart.Workbook is null)
+        {
+            workbookPart.Workbook = workbook;
+        }
 
-    // Append the new worksheet and associate it with the workbook.
-    Sheet sheet = new Sheet() { Id = relationshipId, SheetId = sheetId, Name = sheetName };
-    sheets.Append(sheet);
-    spreadsheetDocument.WorkbookPart.Workbook.Save();
+        Sheets sheets = workbook.GetFirstChild<Sheets>() ?? workbook.AppendChild(new Sheets());
+        string relationshipId = workbookPart.GetIdOfPart(newWorksheetPart);
 
-    // Dispose the document handle.
-    spreadsheetDocument.Dispose();
+        // Get a unique ID for the new worksheet.
+        uint sheetId = 1;
+
+        if (sheets.Elements<Sheet>().Count() > 0)
+        {
+            sheetId = (sheets.Elements<Sheet>().Select(s => s.SheetId?.Value).Max() + 1) ?? (uint)sheets.Elements<Sheet>().Count() + 1;
+        }
+
+        // Give the new worksheet a name.
+        string sheetName = "Sheet" + sheetId;
+
+        // Append the new worksheet and associate it with the workbook.
+        Sheet sheet = new Sheet() { Id = relationshipId, SheetId = sheetId, Name = sheetName };
+        sheets.Append(sheet);
+        workbookPart.Workbook.Save();
+
+        // Dispose the document handle.
+        spreadsheetDocument.Dispose();
+    }
 }

samples/spreadsheet/parse_and_read_a_large_spreadsheet/cs/Program.cs

@@ -1,30 +1,33 @@
-#nullable disable
-
 using DocumentFormat.OpenXml;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Spreadsheet;
 using System;
 using System.Linq;
 
+ReadExcelFileDOM(args[0]);
+ReadExcelFileSAX(args[0]);
+
 // The DOM approach.
 // Note that the code below works only for cells that contain numeric values.
 // 
 static void ReadExcelFileDOM(string fileName)
 {
     using (SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(fileName, false))
     {
-        WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart;
+        WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart ?? spreadsheetDocument.AddWorkbookPart();
         WorksheetPart worksheetPart = workbookPart.WorksheetParts.First();
         SheetData sheetData = worksheetPart.Worksheet.Elements<SheetData>().First();
-        string text;
+        string? text;
+
         foreach (Row r in sheetData.Elements<Row>())
         {
             foreach (Cell c in r.Elements<Cell>())
             {
-                text = c.CellValue.Text;
+                text = c?.CellValue?.Text;
                 Console.Write(text + " ");
             }
         }
+
         Console.WriteLine();
         Console.ReadKey();
     }
@@ -35,7 +38,7 @@ static void ReadExcelFileSAX(string fileName)
 {
     using (SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(fileName, false))
     {
-        WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart;
+        WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart ?? spreadsheetDocument.AddWorkbookPart();
         WorksheetPart worksheetPart = workbookPart.WorksheetParts.First();
 
         OpenXmlReader reader = OpenXmlReader.Create(worksheetPart);

samples/spreadsheet/retrieve_a_dictionary_of_all_named_ranges/cs/Program.cs

@@ -1,10 +1,10 @@
-#nullable disable
-
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Spreadsheet;
 using System;
 using System.Collections.Generic;
 
+GetDefinedNames(args[0]);
+
 static Dictionary<String, String>
     GetDefinedNames(String fileName)
 {
@@ -20,14 +20,25 @@ static Dictionary<String, String>
         var wbPart = document.WorkbookPart;
 
         // Retrieve a reference to the defined names collection.
-        DefinedNames definedNames = wbPart.Workbook.DefinedNames;
+        DefinedNames? definedNames = wbPart?.Workbook?.DefinedNames;
 
         // If there are defined names, add them to the dictionary.
-        if (definedNames != null)
+        if (definedNames is not null)
         {
             foreach (DefinedName dn in definedNames)
-                returnValue.Add(dn.Name.Value, dn.Text);
+            {
+                if (dn?.Name?.Value is not null && dn?.Text is not null)
+                {
+                    returnValue.Add(dn.Name.Value, dn.Text);
+                }
+            }
         }
     }
+
+    foreach (var pair in returnValue)
+    {
+        Console.WriteLine("{0}  {1}", pair.Key, pair.Value);
+    }
+
     return returnValue;
 }