public override Task WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
{
var query = (IQueryable)context.Object;
var queryString = context.HttpContext.Request.QueryString;
var columns = queryString.Value.Contains("$select") ?
OutputFormatter.GetPropertiesFromSelect(queryString.Value, query.ElementType) :
OutputFormatter.GetProperties(query.ElementType);
var stream = new MemoryStream();
using (var document = SpreadsheetDocument.Create(stream, SpreadsheetDocumentType.Workbook))
{
var workbookPart = document.AddWorkbookPart();
workbookPart.Workbook = new Workbook();
var worksheetPart = workbookPart.AddNewPart <WorksheetPart>();
worksheetPart.Worksheet = new Worksheet();
var workbookStylesPart = workbookPart.AddNewPart <WorkbookStylesPart>();
GenerateWorkbookStylesPartContent(workbookStylesPart);
var sheets = workbookPart.Workbook.AppendChild(new Sheets());
var sheet = new Sheet()
{
Id = workbookPart.GetIdOfPart(worksheetPart), SheetId = 1, Name = "Sheet1"
};
sheets.Append(sheet);
workbookPart.Workbook.Save();
var sheetData = worksheetPart.Worksheet.AppendChild(new SheetData());
var headerRow = new Row();
foreach (var column in columns)
{
headerRow.Append(new Cell()
{
CellValue = new CellValue(column.Key),
DataType = new EnumValue <CellValues>(CellValues.String)
});
}
sheetData.AppendChild(headerRow);
foreach (var item in query)
{
var row = new Row();
foreach (var column in columns)
{
var value = OutputFormatter.GetValue(item, column.Key);
var stringValue = $"{value}";
var cell = new Cell();
var underlyingType = column.Value.IsGenericType &&
column.Value.GetGenericTypeDefinition() == typeof(Nullable <>) ?
Nullable.GetUnderlyingType(column.Value) : column.Value;
var typeCode = Type.GetTypeCode(underlyingType);
if (typeCode == TypeCode.DateTime)
{
if (stringValue != string.Empty)
{
cell.CellValue = new CellValue()
{
Text = DateTime.Parse(stringValue).ToOADate().ToString()
};
cell.StyleIndex = (UInt32Value)1U;
}
}
else if (typeCode == TypeCode.Boolean)
{
cell.CellValue = new CellValue(stringValue.ToLower());
cell.DataType = new EnumValue <CellValues>(CellValues.Boolean);
}
else if (IsNumeric(typeCode))
{
cell.CellValue = new CellValue(stringValue);
cell.DataType = new EnumValue <CellValues>(CellValues.Number);
}
else
{
cell.CellValue = new CellValue(stringValue);
cell.DataType = new EnumValue <CellValues>(CellValues.String);
}
row.Append(cell);
}
sheetData.AppendChild(row);
}
workbookPart.Workbook.Save();
}
if (stream?.Length > 0)
{
stream.Seek(0, SeekOrigin.Begin);
}
return(stream.CopyToAsync(context.HttpContext.Response.Body));
}
public static IEnumerable <KeyValuePair <string, Type> > GetProperties(Type type)
{
return(type.GetProperties(BindingFlags.Public | BindingFlags.Instance)
.Where(p => p.CanRead && OutputFormatter.IsSimpleType(p.PropertyType)).Select(p => new KeyValuePair <string, Type>(p.Name, p.PropertyType)));
}