C# Example with ClosedXML and S3 Upload - Asp.Net,C#,Sql server,jquery,Angularjs,Mvc,interview tips and coding tips

using System;

using System.Data;

using System.IO;

using ClosedXML.Excel;

using Amazon;

using Amazon.S3;

using Amazon.S3.Transfer;

using System.Threading.Tasks;

class Program

{

static async Task Main()

{

// 1. Create a sample DataTable

var dt = new DataTable("SampleData");

dt.Columns.Add("ID", typeof(int));

dt.Columns.Add("Name", typeof(string));

dt.Rows.Add(1, "Alice");

dt.Rows.Add(2, "Bob");

// 2. Save to Excel using ClosedXML

string excelFilePath = "output.xlsx";

using (var workbook = new XLWorkbook())

{

var worksheet = workbook.Worksheets.Add(dt, "Sheet1");

workbook.SaveAs(excelFilePath);

}

Console.WriteLine("Excel file created.");

// 3. Upload to AWS S3

string bucketName = "your-s3-bucket-name";

string keyName = "folder/output.xlsx"; // path in S3

var s3Client = new AmazonS3Client(

"your-access-key",

"your-secret-key",

RegionEndpoint.APSouth1 // Use your AWS region

);

var fileTransferUtility = new TransferUtility(s3Client);

await fileTransferUtility.UploadAsync(excelFilePath, bucketName, keyName);

Console.WriteLine("✅ File uploaded to AWS S3.");

}