此接口用于追加写对象，通过 AppendObject 接口创建的对象类型为 Appendable Object，通过 PutObject 上传的对象类型为 Normal Object。
如下代码展示如何追加写对象到目标桶中。
// 从STS服务获取的临时访问密钥和安全令牌（AccessKey、SecretKey、SecurityToken） TOSCredential *credential = [[TOSCredential alloc] initWithAccessKey:@"accesskey" secretKey:@"secretkey" securityToken:@"securityToken"]; TOSEndpoint *tosEndpoint = [[TOSEndpoint alloc] initWithURLString:@"endpoint" withRegion:@"region"]; TOSClientConfiguration *config = [[TOSClientConfiguration alloc] initWithEndpoint:tosEndpoint credential:credential]; TOSClient *client = [[TOSClient alloc] initWithConfiguration:config]; TOSAppendObjectInput *append = [TOSAppendObjectInput new]; append.tosBucket = @"bucket-name"; append.tosKey = @"object-name"; append.tosOffset = 0; append.tosContent = your_data; // NSData TOSTask *task = [client putObjectFromFile:append]; [task continueWithBlock:^id(TOSTask *task) { if (!task.error) { NSLog(@"Append object success."); TOSPutObjectFromFileOutput *output = task.result; } else { NSLog(@"Append object failed, error: %@" ,task.error); } return nil; }];