寻找一种在c#低谷API中传输新创建的excel的好方法

Question

I have created an excel file using NPOI and would like to send this through an API to make it downloadable from that webpage.

My question is that how do I in a good way send this excel file through my API? Can I store this excel file as a Blob or binary instead without saving it as a file to make it more easy to send it?(Don't want to save a file every time I am exporting an excel document)

using (var fileData = new FileStream("ReportName.xls", FileMode.Create))
{
    workbook.Write(fileData);
}

This is what I am using now to save the file.

Answer 1

In general you can usually get a instance of class Stream that represents the client response and write to that instead of the file. You'd also want to set the correct Content-Type header.

For example in ASP.NET Core you could create you're own IActionResult implementation.

public class XlsDownloadResult : IActionResult
{
     private readonly Workbook _workbook;

     public XlsDowloadResult(Workbook workbook) 
     {
           _workbook = workbook;
     }

     public async Task ExecuteResultAsync(ActionContext context)
     {
          var response = context.HttpContext.Response;
          response.Headers.Add("Content-Type", "application/vnd.ms-excel");
           
          // Assuming the workbook object has WriteAsync -- otherwise use sync write
          // and return Task.CompletedTask
          await _workbook.WriteAsync(response.Body);
     }
}

And then you can use it like this

[HttpGet]
public IActionResult Get()
{
    var workbook = CreateWorkbook();
    return new XlsDownloadResult(workbook);
}

Finally -- I'd recommend you make sure you're creating xlsx files not xls files. xls files are deprecated and can cause a number of issues.