Object Storage Service:Upload por acréscimo (C# SDK V2)

using System.Text; // Import the System.Text namespace to process character encoding, such as UTF-8 encoded strings.
using OSS = AlibabaCloud.OSS.V2; // Create an alias for Alibaba Cloud OSS SDK to simplify subsequent use.

var region = "cn-hangzhou"; // Required. Specify the region where the bucket is located. This topic uses China (Hangzhou) as an example. Set the region to cn-hangzhou.
var bucket = "your bucket name";  // Required. Specify the name of the destination bucket. 
var endpoint = null as string;  // Optional. Specify the endpoint that is used to access OSS. This topic uses China (Hangzhou) as an example. Set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.
var key = "your object key"; // Required. Specify the name of the object to which you want to append data. Format: folder/objectName.

// Load the default configurations of OSS SDK. The configurations automatically read credential information, such as AccessKeys, from environment variables.
var cfg = OSS.Configuration.LoadDefault();
// Explicitly specify that environment variables are used to obtain credentials for identity verification. Format: OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET.
cfg.CredentialsProvider = new OSS.Credentials.EnvironmentVariableCredentialsProvider();
// Set the region of the bucket in the configuration.
cfg.Region = region;
// If an endpoint is specified, it overwrites the default endpoint.
if(endpoint != null)
{
    cfg.Endpoint = endpoint;
} 

// Create an OSS client instance using the configuration information.
using var client = new OSS.Client(cfg);

// Define the first part of the content to be appended to the OSS object.
var content1 = "hello,";
// Define the second part of the content to be appended to the OSS object.
var content2 = "oss!";

// Call the AppendObjectAsync method to perform the first append operation.
var result1 = await client.AppendObjectAsync(new OSS.Models.AppendObjectRequest()
{
    // Specify the destination bucket.
    Bucket = bucket,
    // Specify the name of the destination object. 
    Key = key,
    // For the first append operation, the start position must be 0.
    Position = 0,
    Body = new MemoryStream(Encoding.UTF8.GetBytes(content1))
 });

// Call the AppendObjectAsync method to perform the second append operation, starting from the end position of the previous operation.
var result2 = await client.AppendObjectAsync(new OSS.Models.AppendObjectRequest()
{
     // The destination bucket remains unchanged.
    Bucket = bucket,
    // The name of the destination object remains unchanged.
    Key = key,
    // Continue writing from the end position of the previous append operation.
    Position = result1.NextAppendPosition,
    Body = new MemoryStream(Encoding.UTF8.GetBytes(content2))
});

// Print the upload result.
Console.WriteLine("AppendObject done"); // A message indicates that the operation is complete.
Console.WriteLine($"StatusCode: {result2.StatusCode}");  // The HTTP status code.
Console.WriteLine($"RequestId: {result2.RequestId}");   // The request ID, which is used for troubleshooting in Alibaba Cloud.
Console.WriteLine("Response Headers:"); // The response header information.
result2.Headers.ToList().ForEach(x => Console.WriteLine(x.Key + " : " + x.Value));   // Traverse and print all response headers.
Console.WriteLine($"NextAppendPosition: {result2.NextAppendPosition}"); // Output the start position for the next append operation.