Using DynamicConfiguration when writing data using DataTable (#545)

src/MiniExcel/OpenXml/ExcelOpenXmlSheetWriter.cs

@@ -8,7 +8,6 @@
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
-using System.Reflection;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -560,18 +559,30 @@ private void GenerateSheetByDataTable(MiniExcelStreamWriter writer, DataTable va
                 // dimension
                 var maxRowIndex = value.Rows.Count + (_printHeader && value.Rows.Count > 0 ? 1 : 0);
                 var maxColumnIndex = value.Columns.Count;
-                writer.Write($@"<x:dimension ref=""{GetDimensionRef(maxRowIndex, maxColumnIndex)}""/><x:sheetData>");
+                writer.Write($@"<x:dimension ref=""{GetDimensionRef(maxRowIndex, maxColumnIndex)}""/>");
 
+                var props = new List<ExcelColumnInfo>();
+                for (var i = 0; i < value.Columns.Count; i++)
+                {
+                    var columnName = value.Columns[i].Caption ?? value.Columns[i].ColumnName;
+                    var prop = GetColumnInfosFromDynamicConfiguration(columnName);
+                    props.Add(prop);
+                }
+
+                WriteColumnsWidths(writer, props);
+
+                writer.Write("<x:sheetData>");
                 if (_printHeader)
                 {
                     writer.Write($"<x:row r=\"{yIndex}\">");
                     var xIndex = xy.Item1;
-                    foreach (DataColumn c in value.Columns)
+                    foreach (var p in props)
                     {
                         var r = ExcelOpenXmlUtils.ConvertXyToCell(xIndex, yIndex);
-                        WriteC(writer, r, columnName: c.Caption ?? c.ColumnName);
+                        WriteC(writer, r, columnName: p.ExcelColumnName);
                         xIndex++;
                     }
+
                     writer.Write($"</x:row>");
                     yIndex++;
                 }
@@ -613,7 +624,7 @@ private void GenerateSheetByIDataReader(MiniExcelStreamWriter writer, IDataReade
                 for (var i = 0; i < reader.FieldCount; i++)
                 {
                     var columnName = reader.GetName(i);
-                    var prop = GetColumnInfosForIDataReader(columnName);
+                    var prop = GetColumnInfosFromDynamicConfiguration(columnName);
                     props.Add(prop);
                 }
 
@@ -662,7 +673,7 @@ private void GenerateSheetByIDataReader(MiniExcelStreamWriter writer, IDataReade
             }
         }
 
-        private ExcelColumnInfo GetColumnInfosForIDataReader(string columnName)
+        private ExcelColumnInfo GetColumnInfosFromDynamicConfiguration(string columnName)
         {
             var prop = new ExcelColumnInfo
             {

tests/MiniExcelTests/MiniExcelOpenXmlTests.cs

@@ -1242,7 +1242,60 @@ public void DynamicColumnsConfigurationIsUsedWhenCreatingExcelUsingIDataReader()
                 Assert.Contains("Its value", rows[0]);
                 Assert.Contains("Name of something", rows[1]);
                 Assert.Contains("Its value", rows[1]);
-
+
+                Assert.Equal("MiniExcel", rows[0]["Name of something"]);
+                Assert.Equal(1D, rows[0]["Its value"]);
+                Assert.Equal("Github", rows[1]["Name of something"]);
+                Assert.Equal(2D, rows[1]["Its value"]);
+            }
+        }
+
+        [Fact]
+        public void DynamicColumnsConfigurationIsUsedWhenCreatingExcelUsingDataTable()
+        {
+            var path = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.xlsx");
+            var table = new DataTable();
+            {
+                table.Columns.Add("Column1", typeof(string));
+                table.Columns.Add("Column2", typeof(int));
+                table.Rows.Add("MiniExcel", 1);
+                table.Rows.Add("Github", 2);
+            }
+
+            var configuration = new OpenXmlConfiguration
+            {
+                DynamicColumns = new[]
+                {
+                    new DynamicExcelColumn("Column1")
+                    {
+                        Name = "Name of something",
+                        Index = 0,
+                        Width = 150
+                    },
+                    new DynamicExcelColumn("Column2")
+                    {
+                        Name = "Its value",
+                        Index = 1,
+                        Width = 150
+                    }
+                }
+            };
+
+            MiniExcel.SaveAs(path, table, configuration: configuration);
+
+            using (var stream = File.OpenRead(path))
+            {
+                var rows = stream.Query(useHeaderRow: true)
+                    .Select(x => (IDictionary<string, object>)x)
+                    .Select(x => (IDictionary<string, object>)x)
+                    .ToList();
+
+                Assert.Contains("Name of something", rows[0]);
+                Assert.Contains("Its value", rows[0]);
+                Assert.Contains("Name of something", rows[1]);
+                Assert.Contains("Its value", rows[1]);
+
+
                 Assert.Equal("MiniExcel", rows[0]["Name of something"]);
                 Assert.Equal(1D, rows[0]["Its value"]);
                 Assert.Equal("Github", rows[1]["Name of something"]);