Configuring Your AWS SDK for .NET Application

http://docs.aws.amazon.com/sdk-for-net/v3/developer-guide/net-dg-config.html

You can configure your AWS SDK for .NET application to specify AWS credentials, logging options, endpoints, or signature version 4 support with Amazon S3.

The recommended way to configure an application is to use the <aws> element in the project'sApp.config or Web.config file. The following example specifies the AWSRegion and AWSLogging parameters.

<configuration>
  <configSections>
    <section name="aws" type="Amazon.AWSSection, AWSSDK.Core"/>
  </configSections>
  <aws region="us-west-2">
    <logging logTo="Log4Net"/>
  </aws>
</configuration>

Another way to configure an application is to edit the <appSettings> element in the project's App.config or Web.config file. The following example specifies the AWSRegion and AWSLogging parameters.

<configuration>
  <appSettings>
    <add key="AWSRegion" value="us-west-2"/>
    <add key="AWSLogging" value="log4net"/>
  </appSettings>
</configuration>

These settings take effect only after the application has been rebuilt.

Although you can configure an AWS SDK for .NET application programmatically by setting property values in the AWSConfigs class, we recommend you use the aws element instead. The following example specifies the AWSRegion and AWSLogging parameters:

AWSConfigs.AWSRegion = "us-west-2";
AWSConfigs.Logging = LoggingOptions.Log4Net;

Programmatically defined parameters override any values that were specified in an App.config or Web.config file. Some programmatically defined parameter values take effect immediately; others take effect only after you create a new client object. For more information, see Configuring AWS Credentials.