Fix Issue 632, refactor sheet styles (#640)

* fix for issue 606

* fix formatting

* add test

* refactor sheet styles, fix #632

* change tabs to spaces

src/MiniExcel/OpenXml/Constants/ExcelXml.cs

@@ -1,9 +1,4 @@
-using MiniExcelLibs.Attributes;
-using MiniExcelLibs.OpenXml.Models;
-using MiniExcelLibs.Utils;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
+using MiniExcelLibs.OpenXml.Models;
 
 namespace MiniExcelLibs.OpenXml.Constants
 {
@@ -11,15 +6,13 @@ namespace MiniExcelLibs.OpenXml.Constants
     {
         static ExcelXml()
         {
-            DefaultRels = MinifyXml(DefaultRels);
-            DefaultWorkbookXml = MinifyXml(DefaultWorkbookXml);
-            DefaultStylesXml = MinifyXml(DefaultStylesXml);
-            DefaultWorkbookXmlRels = MinifyXml(DefaultWorkbookXmlRels);
-            DefaultSheetRelXml = MinifyXml(DefaultSheetRelXml);
-            DefaultDrawing = MinifyXml(DefaultDrawing);
+            DefaultRels = ExcelOpenXmlUtils.MinifyXml( DefaultRels);
+            DefaultWorkbookXml = ExcelOpenXmlUtils.MinifyXml(DefaultWorkbookXml);
+            DefaultWorkbookXmlRels = ExcelOpenXmlUtils.MinifyXml(DefaultWorkbookXmlRels);
+            DefaultSheetRelXml = ExcelOpenXmlUtils.MinifyXml(DefaultSheetRelXml);
+            DefaultDrawing = ExcelOpenXmlUtils.MinifyXml(DefaultDrawing);
         }
 
-        private static string MinifyXml(string xml) => xml.Replace("\r", "").Replace("\n", "").Replace("\t", "");
 
         internal static readonly string EmptySheetXml = $@"<?xml version=""1.0"" encoding=""utf-8""?><x:worksheet xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main""><x:dimension ref=""A1""/><x:sheetData></x:sheetData></x:worksheet>";
 
@@ -35,146 +28,6 @@ namespace MiniExcelLibs.OpenXml.Constants
     <Relationship Type=""http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings"" Target=""/xl/sharedStrings.xml"" Id=""R3db9602ace778fdb"" />
 </Relationships>";
 
-        internal static readonly string NoneStylesXml = @"<?xml version=""1.0"" encoding=""utf-8""?>
-<x:styleSheet xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"">
-    <x:fonts>
-        <x:font />
-    </x:fonts>
-    <x:fills>
-        <x:fill />
-    </x:fills>
-    <x:borders>
-        <x:border />
-    </x:borders>
-    <x:cellStyleXfs>
-        <x:xf />
-    </x:cellStyleXfs>
-    <x:cellXfs>
-        <x:xf />
-       <x:xf />
-       <x:xf />
-        <x:xf numFmtId=""14"" applyNumberFormat=""1"" />
-    </x:cellXfs>
-</x:styleSheet>";
-
-        #region StyleSheet
-
-        private const int startUpNumFmts = 1;
-        private const string NumFmtsToken = "{{numFmts}}";
-        private const string NumFmtsCountToken = "{{numFmtCount}}";
-
-        private const int startUpCellXfs = 5;
-        private const string cellXfsToken = "{{cellXfs}}";
-        private const string cellXfsCountToken = "{{cellXfsCount}}";
-        
-        internal static readonly string DefaultStylesXml = $@"<?xml version=""1.0"" encoding=""utf-8""?>
-<x:styleSheet xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"">
-    <x:numFmts count=""{NumFmtsCountToken}"">
-        <x:numFmt numFmtId=""0"" formatCode="""" />
-        {NumFmtsToken}
-    </x:numFmts>
-    <x:fonts count=""2"">
-        <x:font>
-            <x:vertAlign val=""baseline"" />
-            <x:sz val=""11"" />
-            <x:color rgb=""FF000000"" />
-            <x:name val=""Calibri"" />
-            <x:family val=""2"" />
-        </x:font>
-        <x:font>
-            <x:vertAlign val=""baseline"" />
-            <x:sz val=""11"" />
-            <x:color rgb=""FFFFFFFF"" />
-            <x:name val=""Calibri"" />
-            <x:family val=""2"" />
-        </x:font>
-    </x:fonts>
-    <x:fills count=""3"">
-        <x:fill>
-            <x:patternFill patternType=""none"" />
-        </x:fill>
-        <x:fill>
-            <x:patternFill patternType=""gray125"" />
-        </x:fill>
-        <x:fill>
-            <x:patternFill patternType=""solid"">
-                <x:fgColor rgb=""284472C4"" />
-            </x:patternFill>
-        </x:fill>
-    </x:fills>
-    <x:borders count=""2"">
-        <x:border diagonalUp=""0"" diagonalDown=""0"">
-            <x:left style=""none"">
-                <x:color rgb=""FF000000"" />
-            </x:left>
-            <x:right style=""none"">
-                <x:color rgb=""FF000000"" />
-            </x:right>
-            <x:top style=""none"">
-                <x:color rgb=""FF000000"" />
-            </x:top>
-            <x:bottom style=""none"">
-                <x:color rgb=""FF000000"" />
-            </x:bottom>
-            <x:diagonal style=""none"">
-                <x:color rgb=""FF000000"" />
-            </x:diagonal>
-        </x:border>
-        <x:border diagonalUp=""0"" diagonalDown=""0"">
-            <x:left style=""thin"">
-                <x:color rgb=""FF000000"" />
-            </x:left>
-            <x:right style=""thin"">
-                <x:color rgb=""FF000000"" />
-            </x:right>
-            <x:top style=""thin"">
-                <x:color rgb=""FF000000"" />
-            </x:top>
-            <x:bottom style=""thin"">
-                <x:color rgb=""FF000000"" />
-            </x:bottom>
-            <x:diagonal style=""none"">
-                <x:color rgb=""FF000000"" />
-            </x:diagonal>
-        </x:border>
-    </x:borders>
-    <x:cellStyleXfs count=""3"">
-        <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""0"" applyAlignment=""1"" applyProtection=""1"">
-            <x:protection locked=""1"" hidden=""0"" />
-        </x:xf>
-        <x:xf numFmtId=""14"" fontId=""1"" fillId=""2"" borderId=""1"" applyNumberFormat=""1"" applyFill=""0"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
-            <x:protection locked=""1"" hidden=""0"" />
-        </x:xf>
-        <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""1"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
-            <x:protection locked=""1"" hidden=""0"" />
-        </x:xf>
-    </x:cellStyleXfs>
-    <x:cellXfs count=""{cellXfsCountToken}"">
-        <x:xf></x:xf>
-        <x:xf numFmtId=""0"" fontId=""1"" fillId=""2"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""0"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
-            <x:alignment horizontal=""left"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
-            <x:protection locked=""1"" hidden=""0"" />
-        </x:xf>
-        <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
-            <x:alignment horizontal=""general"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
-            <x:protection locked=""1"" hidden=""0"" />
-        </x:xf>
-        <x:xf numFmtId=""14"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
-            <x:alignment horizontal=""general"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
-            <x:protection locked=""1"" hidden=""0"" />
-        </x:xf>
-        <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyBorder=""1"" applyAlignment=""1"">
-            <x:alignment horizontal=""fill""/>
-        </x:xf>
-        {cellXfsToken}
-    </x:cellXfs>
-    <x:cellStyles count=""1"">
-        <x:cellStyle name=""Normal"" xfId=""0"" builtinId=""0"" />
-    </x:cellStyles>
-</x:styleSheet>";
-
-        #endregion
-
         internal static readonly string DefaultWorkbookXml = @"<?xml version=""1.0"" encoding=""utf-8""?>
 <x:workbook xmlns:r=""http://schemas.openxmlformats.org/officeDocument/2006/relationships""
     xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"">
@@ -251,51 +104,6 @@ namespace MiniExcelLibs.OpenXml.Constants
         internal static string Sheet(SheetDto sheetDto, int sheetId)
             => $@"<x:sheet name=""{ExcelOpenXmlUtils.EncodeXML(sheetDto.Name)}"" sheetId=""{sheetId}""{(string.IsNullOrWhiteSpace(sheetDto.State) ? string.Empty : $" state=\"{sheetDto.State}\"")} r:id=""{sheetDto.ID}"" />";
 
-        internal static string SetupStyleXml(string styleXml, ICollection<ExcelColumnAttribute> columns)
-        {
-            const int numFmtIndex = 166;
-
-            var sb = new StringBuilder(styleXml);
-            var columnsToApply = GenerateStyleIds(columns);
-
-            var numFmts = columnsToApply.Select((x, i) =>
-            {
-                return new
-                {
-                    numFmt = 
-$@"<x:numFmt numFmtId=""{numFmtIndex + i}"" formatCode=""{x.Format}"" />",
-
-                    cellXfs = 
-$@"<x:xf numFmtId=""{numFmtIndex + i}"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
-    <x:alignment horizontal=""general"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
-    <x:protection locked=""1"" hidden=""0"" />
-</x:xf>"
-                }; 
-            }).ToArray();
-
-            sb.Replace(NumFmtsToken, string.Join(string.Empty, numFmts.Select(x => x.numFmt)));
-            sb.Replace(NumFmtsCountToken, (startUpNumFmts + numFmts.Length).ToString());
-            
-            sb.Replace(cellXfsToken, string.Join(string.Empty, numFmts.Select(x => x.cellXfs)));
-            sb.Replace(cellXfsCountToken, (5 + numFmts.Length).ToString());
-            return sb.ToString();
-        }
-
-        private static IEnumerable<ExcelColumnAttribute> GenerateStyleIds(ICollection<ExcelColumnAttribute> dynamicColumns)
-        {
-            if (dynamicColumns == null)
-                yield break;
-
-            int index = 0;
-            foreach (var g in dynamicColumns?.Where(x => !string.IsNullOrWhiteSpace(x.Format) && new ExcelNumberFormat(x.Format).IsValid).GroupBy(x => x.Format))
-            {
-                foreach (var col in g)
-                    col.FormatId = startUpCellXfs + index;
-
-                yield return g.First();
-                index++;
-            }
     }
 
 }
-}

src/MiniExcel/OpenXml/ExcelOpenXmlSheetWriter.DefaultOpenXml.cs

@@ -1,6 +1,7 @@
 using MiniExcelLibs.Attributes;
 using MiniExcelLibs.OpenXml.Constants;
 using MiniExcelLibs.OpenXml.Models;
+using MiniExcelLibs.OpenXml.Styles;
 using MiniExcelLibs.Utils;
 using MiniExcelLibs.Zip;
 using System;
@@ -364,9 +365,9 @@ namespace MiniExcelLibs.OpenXml
             switch (_configuration.TableStyles)
             {
                 case TableStyles.None:
-                    return ExcelXml.SetupStyleXml(ExcelXml.NoneStylesXml, columns);
+                    return new MinimalSheetStyleBuilder().Build( columns);
                 case TableStyles.Default:
-                    return ExcelXml.SetupStyleXml(ExcelXml.DefaultStylesXml, columns);
+                    return new DefaultSheetStyleBuilder().Build( columns );
                 default:
                     return string.Empty;
             }

src/MiniExcel/OpenXml/ExcelOpenXmlUtils.cs

@@ -9,6 +9,8 @@
 #endif
     static class ExcelOpenXmlUtils
     {
+        public static string MinifyXml( string xml ) => xml.Replace( "\r", "" ).Replace( "\n", "" ).Replace( "\t", "" ).Trim();
+
         /// <summary>
         /// Encode to XML (special characteres: &apos; &quot; &gt; &lt; &amp;)
         /// </summary>

src/MiniExcel/OpenXml/Styles/DefaultSheetStyleBuilder.cs

@@ -0,0 +1,156 @@
+using MiniExcelLibs.Attributes;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace MiniExcelLibs.OpenXml.Styles {
+
+    public class DefaultSheetStyleBuilder : ISheetStyleBuilder
+    {
+        private const int startUpNumFmts = 1;
+        private const string NumFmtsToken = "{{numFmts}}";
+        private const string NumFmtsCountToken = "{{numFmtCount}}";
+
+        private const int startUpCellXfs = 5;
+        private const string cellXfsToken = "{{cellXfs}}";
+        private const string cellXfsCountToken = "{{cellXfsCount}}";
+
+        internal static readonly string DefaultStylesXml = ExcelOpenXmlUtils.MinifyXml
+        ( $@"
+            <?xml version=""1.0"" encoding=""utf-8""?>
+            <x:styleSheet xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"">
+                <x:numFmts count=""{NumFmtsCountToken}"">
+                    <x:numFmt numFmtId=""0"" formatCode="""" />
+                    {NumFmtsToken}
+                </x:numFmts>
+                <x:fonts count=""2"">
+                    <x:font>
+                        <x:vertAlign val=""baseline"" />
+                        <x:sz val=""11"" />
+                        <x:color rgb=""FF000000"" />
+                        <x:name val=""Calibri"" />
+                        <x:family val=""2"" />
+                    </x:font>
+                    <x:font>
+                        <x:vertAlign val=""baseline"" />
+                        <x:sz val=""11"" />
+                        <x:color rgb=""FFFFFFFF"" />
+                        <x:name val=""Calibri"" />
+                        <x:family val=""2"" />
+                    </x:font>
+                </x:fonts>
+                <x:fills count=""3"">
+                    <x:fill>
+                        <x:patternFill patternType=""none"" />
+                    </x:fill>
+                    <x:fill>
+                        <x:patternFill patternType=""gray125"" />
+                    </x:fill>
+                    <x:fill>
+                        <x:patternFill patternType=""solid"">
+                            <x:fgColor rgb=""284472C4"" />
+                        </x:patternFill>
+                    </x:fill>
+                </x:fills>
+                <x:borders count=""2"">
+                    <x:border diagonalUp=""0"" diagonalDown=""0"">
+                        <x:left style=""none"">
+                            <x:color rgb=""FF000000"" />
+                        </x:left>
+                        <x:right style=""none"">
+                            <x:color rgb=""FF000000"" />
+                        </x:right>
+                        <x:top style=""none"">
+                            <x:color rgb=""FF000000"" />
+                        </x:top>
+                        <x:bottom style=""none"">
+                            <x:color rgb=""FF000000"" />
+                        </x:bottom>
+                        <x:diagonal style=""none"">
+                            <x:color rgb=""FF000000"" />
+                        </x:diagonal>
+                    </x:border>
+                    <x:border diagonalUp=""0"" diagonalDown=""0"">
+                        <x:left style=""thin"">
+                            <x:color rgb=""FF000000"" />
+                        </x:left>
+                        <x:right style=""thin"">
+                            <x:color rgb=""FF000000"" />
+                        </x:right>
+                        <x:top style=""thin"">
+                            <x:color rgb=""FF000000"" />
+                        </x:top>
+                        <x:bottom style=""thin"">
+                            <x:color rgb=""FF000000"" />
+                        </x:bottom>
+                        <x:diagonal style=""none"">
+                            <x:color rgb=""FF000000"" />
+                        </x:diagonal>
+                    </x:border>
+                </x:borders>
+                <x:cellStyleXfs count=""3"">
+                    <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""0"" applyAlignment=""1"" applyProtection=""1"">
+                        <x:protection locked=""1"" hidden=""0"" />
+                    </x:xf>
+                    <x:xf numFmtId=""14"" fontId=""1"" fillId=""2"" borderId=""1"" applyNumberFormat=""1"" applyFill=""0"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
+                        <x:protection locked=""1"" hidden=""0"" />
+                    </x:xf>
+                    <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""1"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
+                        <x:protection locked=""1"" hidden=""0"" />
+                    </x:xf>
+                </x:cellStyleXfs>
+                <x:cellXfs count=""{cellXfsCountToken}"">
+                    <x:xf></x:xf>
+                    <x:xf numFmtId=""0"" fontId=""1"" fillId=""2"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""0"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
+                        <x:alignment horizontal=""left"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
+                        <x:protection locked=""1"" hidden=""0"" />
+                    </x:xf>
+                    <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
+                        <x:alignment horizontal=""general"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
+                        <x:protection locked=""1"" hidden=""0"" />
+                    </x:xf>
+                    <x:xf numFmtId=""14"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
+                        <x:alignment horizontal=""general"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
+                        <x:protection locked=""1"" hidden=""0"" />
+                    </x:xf>
+                    <x:xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyBorder=""1"" applyAlignment=""1"">
+                        <x:alignment horizontal=""fill""/>
+                    </x:xf>
+                    {cellXfsToken}
+                </x:cellXfs>
+                <x:cellStyles count=""1"">
+                    <x:cellStyle name=""Normal"" xfId=""0"" builtinId=""0"" />
+                </x:cellStyles>
+            </x:styleSheet>"
+        );
+
+        public string Build( ICollection<ExcelColumnAttribute> columns )
+        {
+            const int numFmtIndex = 166;
+
+            var sb = new StringBuilder( DefaultStylesXml );
+            var columnsToApply = SheetStyleBuilderHelper.GenerateStyleIds( startUpCellXfs, columns );
+
+            var numFmts = columnsToApply.Select( ( x, i ) =>
+            {
+                return new
+                {
+                    numFmt = $@"<x:numFmt numFmtId=""{numFmtIndex + i}"" formatCode=""{x.Format}"" />",
+
+                    cellXfs = $@"<x:xf numFmtId=""{numFmtIndex + i}"" fontId=""0"" fillId=""0"" borderId=""1"" xfId=""0"" applyNumberFormat=""1"" applyFill=""1"" applyBorder=""1"" applyAlignment=""1"" applyProtection=""1"">
+    <x:alignment horizontal=""general"" vertical=""bottom"" textRotation=""0"" wrapText=""0"" indent=""0"" relativeIndent=""0"" justifyLastLine=""0"" shrinkToFit=""0"" readingOrder=""0"" />
+    <x:protection locked=""1"" hidden=""0"" />
+</x:xf>"
+                };
+            } ).ToArray();
+
+            sb.Replace( NumFmtsToken, string.Join( string.Empty, numFmts.Select( x => x.numFmt ) ) );
+            sb.Replace( NumFmtsCountToken, (startUpNumFmts + numFmts.Length).ToString() );
+
+            sb.Replace( cellXfsToken, string.Join( string.Empty, numFmts.Select( x => x.cellXfs ) ) );
+            sb.Replace( cellXfsCountToken, (5 + numFmts.Length).ToString() );
+            return sb.ToString();
+        }
+    }
+
+}

src/MiniExcel/OpenXml/Styles/ISheetStyleBuilder.cs

@@ -0,0 +1,10 @@
+using MiniExcelLibs.Attributes;
+using System.Collections.Generic;
+
+namespace MiniExcelLibs.OpenXml.Styles {
+    public interface ISheetStyleBuilder
+    {
+        string Build( ICollection<ExcelColumnAttribute> columns );
+    }
+
+}

src/MiniExcel/OpenXml/Styles/MinimalSheetStyleBuilder.cs

@@ -0,0 +1,71 @@
+using MiniExcelLibs.Attributes;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace MiniExcelLibs.OpenXml.Styles {
+    public class MinimalSheetStyleBuilder : ISheetStyleBuilder
+    {
+        private const int startUpNumFmts = 1;
+        private const string NumFmtsToken = "{{numFmts}}";
+        private const string NumFmtsCountToken = "{{numFmtCount}}";
+
+        private const int startUpCellXfs = 5;
+        private const string cellXfsToken = "{{cellXfs}}";
+        private const string cellXfsCountToken = "{{cellXfsCount}}";
+
+        internal static readonly string NoneStylesXml = ExcelOpenXmlUtils.MinifyXml
+        ( $@"
+            <?xml version=""1.0"" encoding=""utf-8""?>
+            <x:styleSheet xmlns:x=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"">
+                <x:numFmts count=""{NumFmtsCountToken}"">
+                    <x:numFmt numFmtId=""0"" formatCode="""" />
+                    {NumFmtsToken}
+                </x:numFmts>
+                <x:fonts>
+                    <x:font />
+                </x:fonts>
+                <x:fills>
+                    <x:fill />
+                </x:fills>
+                <x:borders>
+                    <x:border />
+                </x:borders>
+                <x:cellStyleXfs>
+                    <x:xf />
+                </x:cellStyleXfs>
+                <x:cellXfs count=""{cellXfsCountToken}"">
+                    <x:xf />
+                    <x:xf />
+                    <x:xf />
+                    <x:xf numFmtId=""14"" applyNumberFormat=""1"" />
+                    <x:xf />
+                    {cellXfsToken}
+                </x:cellXfs>
+            </x:styleSheet>"
+        );
+        
+        public string Build( ICollection<ExcelColumnAttribute> columns )
+        {
+            const int numFmtIndex = 166;
+
+            var sb = new StringBuilder( NoneStylesXml );
+            var columnsToApply = SheetStyleBuilderHelper.GenerateStyleIds( startUpCellXfs, columns );
+
+            var numFmts = columnsToApply.Select( ( x, i ) => {
+                return new {
+                    numFmt = $@"<x:numFmt numFmtId=""{numFmtIndex + i}"" formatCode=""{x.Format}"" />",
+                    cellXfs = $@"<x:xf numFmtId=""{numFmtIndex + i}"" applyNumberFormat=""1"" />"
+                };
+            } ).ToArray();
+
+            sb.Replace( NumFmtsToken, string.Join( string.Empty, numFmts.Select( x => x.numFmt ) ) );
+            sb.Replace( NumFmtsCountToken, (startUpNumFmts + numFmts.Length).ToString() );
+
+            sb.Replace( cellXfsToken, string.Join( string.Empty, numFmts.Select( x => x.cellXfs ) ) );
+            sb.Replace( cellXfsCountToken, (5 + numFmts.Length).ToString() );
+            return sb.ToString();
+        }
+    }
+
+}

src/MiniExcel/OpenXml/Styles/SheetStyleBuilderHelper.cs

@@ -0,0 +1,24 @@
+using MiniExcelLibs.Attributes;
+using MiniExcelLibs.Utils;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace MiniExcelLibs.OpenXml.Styles {
+    public static class SheetStyleBuilderHelper
+    {
+        public static IEnumerable<ExcelColumnAttribute> GenerateStyleIds( int startUpCellXfs, ICollection<ExcelColumnAttribute> dynamicColumns ) {
+            if ( dynamicColumns == null )
+                yield break;
+
+            int index = 0;
+            foreach ( var g in dynamicColumns?.Where( x => !string.IsNullOrWhiteSpace( x.Format ) && new ExcelNumberFormat( x.Format ).IsValid ).GroupBy( x => x.Format ) ) {
+                foreach ( var col in g )
+                    col.FormatId = startUpCellXfs + index;
+
+                yield return g.First();
+                index++;
+            }
+        }
+    }
+
+}

tests/MiniExcelTests/MiniExcelIssueTests.cs

@@ -1,4 +1,4 @@
-using Dapper;
+using Dapper;
 using MiniExcelLibs.Attributes;
 using MiniExcelLibs.Csv;
 using MiniExcelLibs.Exceptions;
@@ -3692,5 +3692,47 @@ MyProperty4,MyProperty1,MyProperty5,MyProperty2,MyProperty6,,MyProperty3
 
         }
 
+        [Fact]
+        public void Issue632_1()
+        {
+            //https://github.com/mini-software/MiniExcel/issues/632
+            var values = new List<Dictionary<string, object>>();
+
+            foreach ( var item in Enumerable.Range( 1, 100 ) ) {
+                var dict = new Dictionary<string, object>
+                {
+                    { "Id", item },
+                    { "Time", DateTime.Now.ToLocalTime() },
+                    { "CPU Usage (%)", Math.Round( 56.345, 1 ) },
+                    { "Memory Usage (%)", Math.Round( 98.234, 1 ) },
+                    { "Disk Usage (%)", Math.Round( 32.456, 1 ) },
+                    { "CPU Temperature (°C)", Math.Round( 74.234, 1 ) },
+                    { "Voltage (V)", Math.Round( 6.3223, 1 ) },
+                    { "Network Usage (Kb/s)", Math.Round( 4503.23422, 1 ) },
+                    { "Instrument", "QT800050" }
+                };
+                values.Add( dict );
+            }
+
+            var config = new OpenXmlConfiguration
+            {
+                TableStyles = TableStyles.None,
+                DynamicColumns = new DynamicExcelColumn[]
+                {
+                    //new DynamicExcelColumn("Time") { Index = 0, Width = 20, Format = CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern + " " + CultureInfo.CurrentCulture.DateTimeFormat.LongTimePattern },
+                    //new DynamicExcelColumn("Time") { Index = 0, Width = 20, Format = CultureInfo.InvariantCulture.DateTimeFormat.ShortDatePattern + " " + CultureInfo.InvariantCulture.DateTimeFormat.LongTimePattern },
+                    //new DynamicExcelColumn("Time") { Index = 0, Width = 20 },
+                    new DynamicExcelColumn("Time") { Index = 0, Width = 20, Format = "d.MM.yyyy" },
+                }
+            };
+
+            var path = Path.Combine(
+                Path.GetTempPath(),
+                string.Concat( nameof( MiniExcelIssueTests ), "_", nameof( Issue632_1 ), ".xlsx" )
+            );
+            
+            MiniExcel.SaveAs( path, values, excelType: ExcelType.XLSX, configuration: config, overwriteFile: true );
+            
+        }
     }
 }