如何在OneDrive上使用C#创建Excel（.xslx）文件而不安装Microsoft Office

Microsoft Graph API提供文件和Excel API，用于为企业和消费者帐户创建和修改存储在OneDrive中的Excel文件。Microsoft.Graph NuGet包提供了许多用于使用File和Excel API的接口。

{
  Name = "myExcelFile.xslx",
  File = new Microsoft.Graph.File()
};

// Create an empty file in the user's OneDrive.
var excelWorkbookDriveItem = await graphClient.Me.Drive.Root.Children.Request().AddAsync(excelWorkbook);

// Add the contents of a template Excel file.
DriveItem excelDriveItem;
using (Stream ms = ResourceHelper.GetResourceAsStream(ResourceHelper.ExcelTestResource))
{
    //Upload content to the file. ExcelTestResource is an empty template Excel file.
    //https://graph.microsoft.io/en-us/docs/api-reference/v1.0/api/item_uploadcontent
    excelDriveItem = await graphClient.Me.Drive.Items[excelWorkbookDriveItem.Id].Content.Request().PutAsync<DriveItem>(ms);
}

此时，您现在已经在用户（企业或消费者）或组的OneDrive中创建了一个Excel文件。现在，您可以使用Excel API对Excel文件进行更改，而无需使用Excel，也无需了解Excel XML格式。

Java开源解决方案是Apache POI。也许这里有一种设置互操作的方法，但我对Java的了解不够，无法回答这个问题。

当我探索这个问题时，我最终使用了互操作程序集。

如果您从代码中创建数据表或数据网格视图，则可以使用此简单方法保存所有数据。不建议使用此方法，但它可以100%工作，即使您没有在计算机中安装MS Excel。

try
 {
  SaveFileDialog saveFileDialog1 = new SaveFileDialog();
  saveFileDialog1.Filter = "Excel Documents (*.xls)|*.xls";
  saveFileDialog1.FileName = "Employee Details.xls";
  if (saveFileDialog1.ShowDialog() == DialogResult.OK)
  {
  string fname = saveFileDialog1.FileName;
  StreamWriter wr = new StreamWriter(fname);
  for (int i = 0; i <DataTable.Columns.Count; i++)
  {
  wr.Write(DataTable.Columns[i].ToString().ToUpper() + "\t");
  }
  wr.WriteLine();

  //write rows to excel file
  for (int i = 0; i < (DataTable.Rows.Count); i++)
  {
  for (int j = 0; j < DataTable.Columns.Count; j++)
  {
  if (DataTable.Rows[i][j] != null)
  {
  wr.Write(Convert.ToString(getallData.Rows[i][j]) + "\t");
  }
   else
   {
   wr.Write("\t");
   }
   }
   //go to next line
   wr.WriteLine();
   }
   //close file
   wr.Close();
   }
   }
   catch (Exception)
   {
    MessageBox.Show("Error Create Excel Sheet!");
   }

我编写了一个简单的代码，通过使用System.IO.StreamWriter将数据集导出到excel，而不使用excel对象。

下面是代码，它将从数据集中读取所有表，并将它们逐一写入工作表。我从这篇文章中得到了帮助。

public static void exportToExcel(DataSet source, string fileName)
{
        const string endExcelXML = "</Workbook>";
        const string startExcelXML = "<xml version>\r\n<Workbook " +
                 "xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"\r\n" +
                 " xmlns:o=\"urn:schemas-microsoft-com:office:office\"\r\n " +
                 "xmlns:x=\"urn:schemas-    microsoft-com:office:" +
                 "excel\"\r\n xmlns:ss=\"urn:schemas-microsoft-com:" +
                 "office:spreadsheet\">\r\n <Styles>\r\n " +
                 "<Style ss:ID=\"Default\" ss:Name=\"Normal\">\r\n " +
                 "<Alignment ss:Vertical=\"Bottom\"/>\r\n <Borders/>" +
                 "\r\n <Font/>\r\n <Interior/>\r\n <NumberFormat/>" +
                 "\r\n <Protection/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"BoldColumn\">\r\n <Font " +
                 "x:Family=\"Swiss\" ss:Bold=\"1\"/>\r\n </Style>\r\n " +
                 "<Style     ss:ID=\"StringLiteral\">\r\n <NumberFormat" +
                 " ss:Format=\"@\"/>\r\n </Style>\r\n <Style " +
                 "ss:ID=\"Decimal\">\r\n <NumberFormat " +
                 "ss:Format=\"0.0000\"/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"Integer\">\r\n <NumberFormat " +
                 "ss:Format=\"0\"/>\r\n </Style>\r\n <Style " +
                 "ss:ID=\"DateLiteral\">\r\n <NumberFormat " +
                 "ss:Format=\"mm/dd/yyyy;@\"/>\r\n </Style>\r\n " +
                 "</Styles>\r\n ";
        System.IO.StreamWriter excelDoc = null;
        excelDoc = new System.IO.StreamWriter(fileName);

        int sheetCount = 1;
        excelDoc.Write(startExcelXML);
        foreach (DataTable table in source.Tables)
        {
            int rowCount = 0;
            excelDoc.Write("<Worksheet ss:Name=\"" + table.TableName + "\">");
            excelDoc.Write("<Table>");
            excelDoc.Write("<Row>");
            for (int x = 0; x < table.Columns.Count; x++)
            {
                excelDoc.Write("<Cell ss:StyleID=\"BoldColumn\"><Data ss:Type=\"String\">");
                excelDoc.Write(table.Columns[x].ColumnName);
                excelDoc.Write("</Data></Cell>");
            }
            excelDoc.Write("</Row>");
            foreach (DataRow x in table.Rows)
            {
                rowCount++;
                //if the number of rows is > 64000 create a new page to continue output
                if (rowCount == 64000)
                {
                    rowCount = 0;
                    sheetCount++;
                    excelDoc.Write("</Table>");
                    excelDoc.Write(" </Worksheet>");
                    excelDoc.Write("<Worksheet ss:Name=\"" + table.TableName + "\">");
                    excelDoc.Write("<Table>");
                }
                excelDoc.Write("<Row>"); //ID=" + rowCount + "
                for (int y = 0; y < table.Columns.Count; y++)
                {
                    System.Type rowType;
                    rowType = x[y].GetType();
                    switch (rowType.ToString())
                    {
                        case "System.String":
                            string XMLstring = x[y].ToString();
                            XMLstring = XMLstring.Trim();
                            XMLstring = XMLstring.Replace("&", "&");
                            XMLstring = XMLstring.Replace(">", ">");
                            XMLstring = XMLstring.Replace("<", "<");
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                           "<Data ss:Type=\"String\">");
                            excelDoc.Write(XMLstring);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DateTime":
                            //Excel has a specific Date Format of YYYY-MM-DD followed by  
                            //the letter 'T' then hh:mm:sss.lll Example 2005-01-31T24:01:21.000
                            //The Following Code puts the date stored in XMLDate 
                            //to the format above
                            DateTime XMLDate = (DateTime)x[y];
                            string XMLDatetoString = ""; //Excel Converted Date
                            XMLDatetoString = XMLDate.Year.ToString() +
                                 "-" +
                                 (XMLDate.Month < 10 ? "0" +
                                 XMLDate.Month.ToString() : XMLDate.Month.ToString()) +
                                 "-" +
                                 (XMLDate.Day < 10 ? "0" +
                                 XMLDate.Day.ToString() : XMLDate.Day.ToString()) +
                                 "T" +
                                 (XMLDate.Hour < 10 ? "0" +
                                 XMLDate.Hour.ToString() : XMLDate.Hour.ToString()) +
                                 ":" +
                                 (XMLDate.Minute < 10 ? "0" +
                                 XMLDate.Minute.ToString() : XMLDate.Minute.ToString()) +
                                 ":" +
                                 (XMLDate.Second < 10 ? "0" +
                                 XMLDate.Second.ToString() : XMLDate.Second.ToString()) +
                                 ".000";
                            excelDoc.Write("<Cell ss:StyleID=\"DateLiteral\">" +
                                         "<Data ss:Type=\"DateTime\">");
                            excelDoc.Write(XMLDatetoString);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Boolean":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                        "<Data ss:Type=\"String\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Int16":
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            excelDoc.Write("<Cell ss:StyleID=\"Integer\">" +
                                    "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Decimal":
                        case "System.Double":
                            excelDoc.Write("<Cell ss:StyleID=\"Decimal\">" +
                                  "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DBNull":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                  "<Data ss:Type=\"String\">");
                            excelDoc.Write("");
                            excelDoc.Write("</Data></Cell>");
                            break;
                        default:
                            throw (new Exception(rowType.ToString() + " not handled."));
                    }
                }
                excelDoc.Write("</Row>");
            }
            excelDoc.Write("</Table>");
            excelDoc.Write(" </Worksheet>");
            sheetCount++;
        }


        excelDoc.Write(endExcelXML);
        excelDoc.Close();
    }

我同意生成XML电子表格，这里有一个关于如何在C#中实现它的示例（每个人都在VB9:P中写博客）http://www.aaron-powell.com/linq-to-xml-to-excel

您只需使用Excel XML格式将其写入XML，并以.XLS扩展名命名，它将以Excel打开。您可以控制XML文件标题中的所有格式（粗体、宽度等）。

维基百科中有一个XML示例。