# .NET code examples
<a name="CodeSamples.DotNet"></a>

**Topics**
+ [.NET: Setting your Amazon credentials](#CodeSamples.DotNet.Credentials)
+ [.NET: Setting the Amazon Region and endpoint](#CodeSamples.DotNet.RegionAndEndpoint)

This guide contains .NET code snippets and ready-to-run programs. You can find these code examples in the following sections:
+ [Working with items and attributes in DynamoDB](WorkingWithItems.md)
+ [Working with tables and data in DynamoDB](WorkingWithTables.md)
+ [Querying tables in DynamoDB](Query.md)
+ [Scanning tables in DynamoDB](Scan.md)
+ [Improving data access with secondary indexes in DynamoDB](SecondaryIndexes.md)
+ [Working with the .NET document model in DynamoDB](DotNetSDKMidLevel.md)
+ [Working with the .NET object persistence model and DynamoDB](DotNetSDKHighLevel.md)
+ [Change data capture for DynamoDB Streams](Streams.md)

You can get started quickly by using the Amazon SDK for .NET with the Toolkit for Visual Studio.

**To run the .NET code examples (using Visual Studio)**

1. Download and install [Microsoft Visual Studio](https://www.visualstudio.com).

1. (Optional) Download and install the [Toolkit for Visual Studio](http://www.amazonaws.cn/visualstudio/).

1. Set up your Amazon credentials. Configure a credentials profile in your shared Amazon credentials file (`~/.aws/credentials`). For more information, see [Configure Amazon credentials](https://docs.amazonaws.cn/sdk-for-net/v3/developer-guide/net-dg-config-creds.html) in the *Amazon SDK for .NET Developer Guide*.

1. Start Visual Studio. Choose **File**, **New**, **Project**.

1. Search for **Console App**, select the C\$1 template that targets .NET, and then choose **Next**. Configure your project name and location, and then choose **Create**.

1. Add the Amazon SDK for DynamoDB NuGet package to your project:

   1. In Solution Explorer, open the context (right-click) menu for your project, and then choose **Manage NuGet Packages**.

   1. In NuGet Package Manager, choose **Browse**.

   1. In the search box, enter **AWSSDK.DynamoDBv2**, and wait for the search to complete.

   1. Choose **AWSSDK.DynamoDBv2**, and then choose **Install**.

1. In your Visual Studio project, open `Program.cs`. Replace the contents with the code example from the documentation page that you want to run.

1. To run the code, choose **Start** in the Visual Studio toolbar.

The Amazon SDK for .NET provides thread-safe clients for working with DynamoDB. As a best practice, your applications should create one client and reuse the client between threads.

For more information, see [Amazon SDK for .NET](http://www.amazonaws.cn/sdk-for-net).

**Note**  
The code examples in this guide are intended for use with the latest version of the Amazon SDK for .NET.

## .NET: Setting your Amazon credentials
<a name="CodeSamples.DotNet.Credentials"></a>

The Amazon SDK for .NET requires that you provide Amazon credentials to your application at runtime. The code examples in this guide assume that you are using the SDK Store to manage your Amazon credentials file, as described in [Using the SDK store](https://docs.amazonaws.cn/sdk-for-net/v3/developer-guide/net-dg-config-creds.html#sdk-store) in the *Amazon SDK for .NET Developer Guide*.

The Toolkit for Visual Studio supports multiple sets of credentials from any number of accounts. Each set is referred to as a *profile*. Visual Studio adds entries to the project's `App.config` file so that your application can find the Amazon credentials at runtime.

The following example shows the default `App.config` file that is generated when you create a new project using Toolkit for Visual Studio.

```
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <appSettings>
    <add key="AWSProfileName" value="default"/>
    <add key="AWSRegion" value="us-west-2" />
 </appSettings>
</configuration>
```

At runtime, the program uses the `default` set of Amazon credentials, as specified by the `AWSProfileName` entry. The Amazon credentials themselves are kept in the SDK Store in encrypted form. The Toolkit for Visual Studio provides a graphical user interface for managing your credentials, all from within Visual Studio. For more information, see [Specifying credentials](https://docs.amazonaws.cn/AWSToolkitVS/latest/UserGuide/tkv_setup.html#creds) in the *Amazon Toolkit for Visual Studio User Guide*.

**Note**  
By default, the code examples access DynamoDB in the US West (Oregon) Region. You can change the Region by modifying the `AWSRegion` entry in the App.config file. You can set `AWSRegion` to any Region where DynamoDB is available. For a complete list, see [Amazon regions and endpoints](https://docs.amazonaws.cn/general/latest/gr/rande.html#ddb_region) in the *Amazon Web Services General Reference*.

## .NET: Setting the Amazon Region and endpoint
<a name="CodeSamples.DotNet.RegionAndEndpoint"></a>

By default, the code examples access DynamoDB in the US West (Oregon) Region. You can change the Region by modifying the `AWSRegion` entry in the `App.config` file. Or, you can change the Region by modifying the `AmazonDynamoDBClient` properties.

The following code example instantiates a new `AmazonDynamoDBClient`. The client is modified so that the code runs against DynamoDB in a different Region.

```
AmazonDynamoDBConfig clientConfig = new AmazonDynamoDBConfig();
// This client will access the US East 1 region.
clientConfig.RegionEndpoint = RegionEndpoint.USEast1;
AmazonDynamoDBClient client = new AmazonDynamoDBClient(clientConfig);
```

For a complete list of Regions, see [Amazon regions and endpoints](https://docs.amazonaws.cn/general/latest/gr/rande.html#ddb_region) in the *Amazon Web Services General Reference*.

If you want to run the code examples using DynamoDB locally on your computer, set the endpoint as follows.

```
AmazonDynamoDBConfig clientConfig = new AmazonDynamoDBConfig();
// Set the endpoint URL
clientConfig.ServiceURL = "http://localhost:8000";
AmazonDynamoDBClient client = new AmazonDynamoDBClient(clientConfig);
```