Getting started with OSS SDK for .NET - Object Storage Service

This topic describes how to use Object Storage Service (OSS) SDK for .NET to perform routine operations such as creating a bucket, uploading an object, and downloading an object.

Create a bucket

A bucket is a global namespace in OSS. A bucket is a container that is used to store objects.

The following sample code provides an example on how to create a bucket:

using Aliyun.OSS;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of your bucket. 
var bucketName = "yourBucketName";

// Create an OSSClient instance. 
var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
try
{
    // Create a bucket. 
    var bucket = client.CreateBucket(bucketName);
    Console.WriteLine("Create bucket succeeded, {0} ", bucket.Name);
}
catch (Exception ex)
{
    Console.WriteLine("Create bucket failed, {0}", ex.Message);
}

Upload an object

The following sample code provides an example on how to upload an object to OSS by using streaming upload:

using Aliyun.OSS;

// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. 
var objectName = "exampledir/exampleobject.txt";
// Specify the full path of the local file. Example: D:\\localpath\\examplefile.txt. By default, if you do not specify the local file, the local file is uploaded from the path of the project to which the sample program belongs. 
var localFilename = "D:\\localpath\\examplefile.txt";
// Create an OSSClient instance. 
var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
try
{
    // Upload the local file. 
    var result = client.PutObject(bucketName, objectName, localFilename);
    Console.WriteLine("Put object succeeded, ETag: {0} ", result.ETag);
}
catch (Exception ex)
{
    Console.WriteLine("Put object failed, {0}", ex.Message);
}

Download an object

The following sample code provides an example on how to download a specific object to your computer:

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

// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. 
var objectName = "exampledir/exampleobject.txt";
// Download the object to D:\\localpath. After the object is downloaded, the local file is named examplefile.txt. If a file with the same name already exists, the downloaded object overwrites the file. Otherwise, the downloaded object is saved in the path. 
// If you do not specify a path for the downloaded object, the downloaded object is saved to the path of the project to which the sample program belongs. 
var downloadFilename = "D:\\localpath\\examplefile.txt";
// Create an OSSClient instance. 
var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
try
{   
    // Download the object. 
    var result = client.GetObject(bucketName, objectName);
    using (var requestStream = result.Content)
    {
        using (var fs = File.Open(downloadFilename, FileMode.OpenOrCreate))
        {
            int length = 4 * 1024;
            var buf = new byte[length];
            do
            {
                length = requestStream.Read(buf, 0, length);
                fs.Write(buf, 0, length);
            } while (length != 0);
        }
    }
    Console.WriteLine("Get object succeeded");
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

List objects

The following sample code provides an example on how to list objects in a bucket. By default, 100 objects are listed:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Create an OSSClient instance. 
var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
try
{
    var objects = new List<string>();
    ObjectListing result = null;
    string nextMarker = string.Empty;
    do
    {
        var listObjectsRequest = new ListObjectsRequest(bucketName)
        {
            Marker = nextMarker,
        };
        // List objects. 
        result = client.ListObjects(listObjectsRequest);
        foreach (var summary in result.ObjectSummaries)
        {
            Console.WriteLine(summary.Key);
            objects.Add(summary.Key);
        }
        nextMarker = result.NextMarker;
    } while (result.IsTruncated);
    Console.WriteLine("List objects of bucket:{0} succeeded ", bucketName);
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

Delete an object

The following sample code provides an example on how to delete an object:

using Aliyun.OSS;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. 
var objectName = "exampledir/exampleobject.txt";
// Create an OSSClient instance. 
var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
try
{
    // Delete the object. 
    client.DeleteObject(bucketName, objectName);
    Console.WriteLine("Delete object succeeded");
}
catch (Exception ex)
{
    Console.WriteLine("Delete object failed, {0}", ex.Message);
}

References

Upload an object
- For the complete sample code that is used to upload an object, visit GitHub.
- For more information about the API operation that you can call to upload an object, see PutObject.
Download an object
- For the complete sample code that is used to download an object, visit GitHub.
- For more information about the API operation that you can call to download an object, see GetObject.
List objects
- For the complete sample code that is used to list objects, visit GitHub.
- For more information about the API operation that you can call to list objects, see GetBucket (ListObjects).
Delete an object
- For the complete sample code that is used to delete an object, visit GitHub.
- For more information about the API operation that you can call to delete an object, see DeleteObject.