或者您可以通过UI界面来安装它.

 一切就绪，现在创建一个控制器，命名为： ImportExportController ，添加后，让我们编写导出方法。

为了方便演示，我在wwwroot文件夹中创建了一个excel文件，所以我们就需要去获取我们的项目的绝对路径。

 public class ImportExportController : ControllerBase
 {
 private readonly IHostingEnvironment _hostingEnvironment;

 public ImportExportController(IHostingEnvironment hostingEnvironment)
 {
 _hostingEnvironment = hostingEnvironment;
 }
 }

 ExcelPackage 在 OfficeOpenXml 命名空间中可用的类将用于读写xlsx。定义名为“Export”的新Web api操作方法，该方法返回生成的xlsx文件的URL。所以这是将数据导出到xlsx的完整代码。其中您需要 using OfficeOpenXml;

 [HttpGet]
 public string Export()
 {
 string sWebRootFolder = _hostingEnvironment.WebRootPath;
 string sFileName = @"demo.xlsx";
 string URL = string.Format("{0}://{1}/{2}", Request.Scheme, Request.Host, sFileName);
 FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
 if (file.Exists)
 {
 file.Delete();
 file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
 }
 using (ExcelPackage package = new ExcelPackage(file))
 {
 // add a new worksheet to the empty workbook
 ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("Employee");
 //First add the headers
 worksheet.Cells[1, 1].Value = "ID";
 worksheet.Cells[1, 2].Value = "Name";
 worksheet.Cells[1, 3].Value = "Gender";
 worksheet.Cells[1, 4].Value = "Salary (in $)";

 //Add values
 worksheet.Cells["A2"].Value = 1000;
 worksheet.Cells["B2"].Value = "Jon";
 worksheet.Cells["C2"].Value = "M";
 worksheet.Cells["D2"].Value = 5000;

 worksheet.Cells["A3"].Value = 1001;
 worksheet.Cells["B3"].Value = "Graham";
 worksheet.Cells["C3"].Value = "M";
 worksheet.Cells["D3"].Value = 10000;

 worksheet.Cells["A4"].Value = 1002;
 worksheet.Cells["B4"].Value = "Jenny";
 worksheet.Cells["C4"].Value = "F";
 worksheet.Cells["D4"].Value = 5000;

 package.Save(); //Save the workbook.
 }
 return URL;
 }

就这样。现在，当您运行此应用程序并调用export方法时。完成后，访问wwwroot您的应用程序的文件夹。您应该在系统上看到“demo.xlsx”。当你打开它时，你应该看到以下内容。

您还可以对标题进行加粗，这些并不是EPPlus.Core给我们提供的，你需要引用 using OfficeOpenXml; using OfficeOpenXml.Style;

using (var cells = worksheet.Cells[1, 1, 1, 4])
 {
 cells.Style.Font.Bold = true;
 cells.Style.Fill.PatternType = ExcelFillStyle.Solid;
 cells.Style.Fill.BackgroundColor.SetColor(Color.LightGray);
 }

 关于导入，其实真实的情况还是比较复杂的，我们这里就不进行验证了，对于演示，我们只是读取刚刚保存的文件。 ImportAPI 将读取文件并以格式化的字符串返回文件内容。以下是导入API的完整代码，用于读取xlsx，创建文件内容的格式化字符串并返回相同的内容。

[HttpGet]
 [Route("Import")]
 public string Import()
 {
 string sWebRootFolder = _hostingEnvironment.WebRootPath;
 string sFileName = @"demo.xlsx";
 FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
 try
 {
 using (ExcelPackage package = new ExcelPackage(file))
 {
 StringBuilder sb = new StringBuilder();
 ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
 int rowCount = worksheet.Dimension.Rows;
 int ColCount = worksheet.Dimension.Columns;
 bool bHeaderRow = true;
 for (int row = 1; row <= rowCount; row++)
 {
 for (int col = 1; col <= ColCount; col++)
 {
 if (bHeaderRow)
 {
 sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t");
 }
 else
 {
 sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t");
 }
 }
 sb.Append(Environment.NewLine);
 }
 return sb.ToString();
 }
 }
 catch (Exception ex)
 {
 return "Some error occured while importing." + ex.Message;
 }
 }

总结