Cenário do problema
Ao usar o kit de desenvolvimento de software (SDK) de C# para enviar um grande volume de conteúdo, ocorre o erro "Invalid URI: The Uri string is too long".
Soluções
Faça login no OpenAPI Explorer da Alibaba Cloud para gerar código de depuração.
Ative a opção Generate code in common mode e especifique os parâmetros.

Após obter o código, altere o método de passagem de parâmetros de URL para Body.
A figura a seguir mostra as duas modificações principais:

Código modificado:
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using Tea;
using Tea.Utils;
namespace AlibabaCloud.SDK.Sample
{
public class Sample
{
/**
* Use an AccessKey pair to initialize the client.
* @return Client
* @throws Exception
*/
public static AlibabaCloud.OpenApiClient.Client CreateClient()
{
// Leaking the code may expose your AccessKey pair and compromise the security of all your resources. The following sample code is for reference only.
// Use the more secure Security Token Service (STS) method. For more information, see the related documents below.
AlibabaCloud.OpenApiClient.Models.Config config = new AlibabaCloud.OpenApiClient.Models.Config
{
// Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_ID environment variable is set.
AccessKeyId = "xxxxxx",
// Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_SECRET environment variable is set.
AccessKeySecret = "xxxxxx",
};
// For more information about endpoints, see the related documents.
config.Endpoint = "dm.aliyuncs.com";
return new AlibabaCloud.OpenApiClient.Client(config);
}
/**
* API-related information
* @param path params
* @return OpenApi.Params
*/
public static AlibabaCloud.OpenApiClient.Models.Params CreateApiInfo()
{
AlibabaCloud.OpenApiClient.Models.Params params_ = new AlibabaCloud.OpenApiClient.Models.Params
{
// The name of the API operation.
Action = "SingleSendMail",
// The version of the API operation.
Version = "2015-11-23",
// The protocol.
Protocol = "HTTPS",
// The HTTP method.
Method = "POST",
AuthType = "AK",
Style = "RPC",
// The path of the API operation.
Pathname = "/",
// The format of the request body.
ReqBodyType = "formdata",
// The format of the response body.
BodyType = "json",
};
return params_;
}
public static void Main(string[] args)
{
AlibabaCloud.OpenApiClient.Client client = CreateClient();
AlibabaCloud.OpenApiClient.Models.Params params_ = CreateApiInfo();
// query params
Dictionary<string, object> queries = new Dictionary<string, object>() { };
queries["AccountName"] = "xxxxxx";
queries["AddressType"] = 1;
queries["ReplyToAddress"] = false;
queries["ToAddress"] = "xxxxxx";
queries["Subject"] = "test2";
queries["HtmlBody"] = "test long content";
// runtime options
AlibabaCloud.TeaUtil.Models.RuntimeOptions runtime = new AlibabaCloud.TeaUtil.Models.RuntimeOptions();
AlibabaCloud.OpenApiClient.Models.OpenApiRequest request = new AlibabaCloud.OpenApiClient.Models.OpenApiRequest
{
Body = queries,
};
// When you copy the code to run, print the return value of the API operation.
// The return value is of the Map type. You can obtain three types of data from the Map: the response body, response headers, and the HTTP status code.
client.CallApi(params_, request, runtime);
}
}
}
Referências: