Check whether a bucket exists (C# SDK V1)

Prerequisites

Before you begin, ensure that you have:

• The oss:GetBucketAcl permission on the target bucket. For details, see Attach a custom policy to a RAM user.

• An OSSClient instance initialized with a valid endpoint and credentials. For initialization options including custom domain names and Security Token Service (STS), see Initialization.

Note: The examples below use the public endpoint for the China (Hangzhou) region. To access OSS from other Alibaba Cloud services in the same region, use an internal endpoint instead. For a full list of regions and endpoints, see Regions and endpoints.

Check whether a bucket exists

The following example calls DoesBucketExist() and branches on the result.

using System;
using Aliyun.OSS;
using Aliyun.OSS.Common;

namespace Samples
{
    public class Program
    {
        public static void Main(string[] args)
        {
            // Replace with the endpoint for the region where your bucket is located.
            // Example: https://oss-cn-hangzhou.aliyuncs.com
            var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";

            // Load credentials from environment variables.
            // Set OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET before running this example.
            var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
            var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");

            var bucketName = "examplebucket";

            // Set the region to match your endpoint. Example: cn-hangzhou
            const string region = "cn-hangzhou";

            // Create a ClientConfiguration instance and set the signature version to V4.
            var conf = new ClientConfiguration();
            conf.SignatureVersion = SignatureVersion.V4;

            var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
            client.SetRegion(region);

            try
            {
                // Returns true if the bucket exists; false if it does not exist.
                var exists = client.DoesBucketExist(bucketName);

                if (exists)
                {
                    Console.WriteLine("Bucket '{0}' exists.", bucketName);
                }
                else
                {
                    Console.WriteLine("Bucket '{0}' does not exist.", bucketName);
                    // Add bucket creation logic here if needed.
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Failed to check bucket existence: {0}", ex.Message);
            }
        }
    }
}

For the complete sample, see DoesBucketExistSample.cs on GitHub.