Initial commit of the ClosedXML library

Establishes the foundational structure, core Excel functionality, and tooling.

- Implements base components for cells, ranges, columns, and rows.
- Integrates a custom calculation engine with a wide range of Excel functions.
- Adds comprehensive support for styling, conditional formatting, data validation, comments, pictures, and charts.
- Configures build setup, project metadata (NuGet), and developer guidelines.
- Includes editor and Git attributes for consistent code style and line endings.

ClosedXML_Examples/Ranges/NamedRanges.cs

@@ -0,0 +1,85 @@
+using ClosedXML.Excel;
+using System;
+
+namespace ClosedXML_Examples.Misc
+{
+    public class NamedRanges : IXLExample
+    {
+        #region Methods
+
+        // Public
+        public void Create(String filePath)
+        {
+            var wb = new XLWorkbook();
+            var wsPresentation = wb.Worksheets.Add("Presentation");
+            var wsData = wb.Worksheets.Add("Data");
+
+            // Fill up some data
+            wsData.Cell(1, 1).Value = "Name";
+            wsData.Cell(1, 2).Value = "Age";
+            wsData.Cell(2, 1).Value = "Tom";
+            wsData.Cell(2, 2).Value = 30;
+            wsData.Cell(3, 1).Value = "Dick";
+            wsData.Cell(3, 2).Value = 25;
+            wsData.Cell(4, 1).Value = "Harry";
+            wsData.Cell(4, 2).Value = 29;
+
+            // Create a named range with the data:
+            wsData.Range("A2:B4").AddToNamed("PeopleData"); // Default named range scope is Workbook
+
+            // Create a hidden named range
+            wb.NamedRanges.Add("Headers", wsData.Range("A1:B1")).Visible = false;
+
+            // Create a hidden named range n worksheet scope
+            wsData.NamedRanges.Add("HeadersAndData", wsData.Range("A1:B4")).Visible = false;
+
+            // Let's use the named range in a formula:
+            wsPresentation.Cell(1, 1).Value = "People Count:";
+            wsPresentation.Cell(1, 2).FormulaA1 = "COUNT(PeopleData)";
+
+            // Create a named range with worksheet scope:
+            wsPresentation.Range("B1").AddToNamed("PeopleCount", XLScope.Worksheet);
+
+            // Let's use the named range:
+            wsPresentation.Cell(2, 1).Value = "Total:";
+            wsPresentation.Cell(2, 2).FormulaA1 = "PeopleCount";
+
+            // Copy the data in a named range:
+            wsPresentation.Cell(4, 1).Value = "People Data:";
+            wsPresentation.Cell(5, 1).Value = wb.Range("PeopleData");
+
+            /////////////////////////////////////////////////////////////////////////
+            // For the Excel geeks out there who actually know about
+            // named ranges with relative addresses, you can
+            // create such a thing with the following methods:
+
+            // The following creates a relative named range pointing to the same row
+            // and one column to the right. For example if the current cell is B4
+            // relativeRange1 will point to C4.
+            wsPresentation.NamedRanges.Add("relativeRange1", "Presentation!B1");
+
+            // The following creates a ralative named range pointing to the same row
+            // and one column to the left. For example if the current cell is D2
+            // relativeRange2 will point to C2.
+            wb.NamedRanges.Add("relativeRange2", "Presentation!XFD1");
+
+            // Explanation: The address of a relative range always starts at A1
+            // and moves from then on. To get the desired relative range just
+            // add or subtract the required rows and/or columns from A1.
+            // Column -1 = XFD, Column -2 = XFC, etc.
+            // Row -1 = 1048576, Row -2 = 1048575, etc.
+            /////////////////////////////////////////////////////////////////////////
+
+            wsData.Columns().AdjustToContents();
+            wsPresentation.Columns().AdjustToContents();
+
+            wb.SaveAs(filePath);
+        }
+
+        // Private
+
+        // Override
+
+        #endregion Methods
+    }
+}