how can we upload multiple files in aws s3 bucket

To upload multiple files to an AWS S3 bucket and get the URLs of the uploaded files in C#, you can use the AWS SDK for .NET. Below is an example of how to do this:

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Amazon;
using Amazon.S3;
using Amazon.S3.Model;

namespace S3UploadExample
{
    class Program
    {
        private const string bucketName = "YOUR_BUCKET_NAME";
        private static readonly RegionEndpoint bucketRegion = RegionEndpoint.YOUR_REGION;
        private static IAmazonS3 s3Client;

        static async Task Main(string[] args)
        {
            s3Client = new AmazonS3Client(bucketRegion);

            List filePaths = new List
            {
                "FILE_PATH_1",
                "FILE_PATH_2",
                // Add more file paths as needed
            };

            foreach (var filePath in filePaths)
            {
                await UploadFileAsync(filePath);
            }
        }

        private static async Task UploadFileAsync(string filePath)
        {
            try
            {
                var fileTransferUtility = new TransferUtility(s3Client);

                var keyName = "YOUR_PREFIX/" + Guid.NewGuid() + System.IO.Path.GetExtension(filePath);
                var fileTransferUtilityRequest = new TransferUtilityUploadRequest
                {
                    BucketName = bucketName,
                    FilePath = filePath,
                    Key = keyName,
                    CannedACL = S3CannedACL.PublicRead
                };

                await fileTransferUtility.UploadAsync(fileTransferUtilityRequest);

                var url = GeneratePreSignedURL(bucketName, keyName);
                Console.WriteLine($"File upload successful. URL: {url}");
            }
            catch (AmazonS3Exception e)
            {
                Console.WriteLine("Error encountered on server. Message:'{0}' when writing an object", e.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine("Unknown encountered on server. Message:'{0}' when writing an object", e.Message);
            }
        }

        private static string GeneratePreSignedURL(string bucketName, string objectKey)
        {
            var request = new GetPreSignedUrlRequest
            {
                BucketName = bucketName,
                Key = objectKey,
                Expires = DateTime.Now.AddHours(1)
            };

            string url = s3Client.GetPreSignedURL(request);
            return url;
        }
    }
}