如何在AmazonEC2Client中用自己的enum替换region？

Question

在我的aspnet core 3.1项目中，我使用客户端为aws获取所有实例列表为我.在构造函数AmazonEC2Client第三个参数是接受RegionEndPoint的类，我想把enum代替RegionEndPoint。

我的方法是这样的。

      public static async Task<List<string>> AwsList(string awsAccessKeyId, string 
     awsSecretAccessKey) // should AwsRegion region as 3rd paramater
    {
        AmazonEC2Client client = new AmazonEC2Client(awsAccessKeyId,awsSecretAccessKey, 
        RegionEndpoint.EUWest1); // replace RegionEndpoint.EUWest1 with enum paramater

        bool done = false;
        var instanceIds = new List<string>();
        DescribeInstanceTypesRequest request = new DescribeInstanceTypesRequest();

        while (!done)
        {
            DescribeInstanceTypesResponse response = await 
           client.DescribeInstanceTypesAsync(request);
            foreach ( var instanceType in response.InstanceTypes.Where(x => 
            x.MemoryInfo.SizeInMiB >= 2048 && x.VCpuInfo.DefaultVCpus >= 2))
            {
                 instanceIds.Add(instanceType.InstanceType);
            }

            request.NextToken= response.NextToken;

            if (response.NextToken == null)
            {
                done = true;
            }
        }

        return instanceIds;
    }

我想把第三个参数是enum放到我的方法中，然后用enum代替Region。由于没有接受enum的构造函数，我如何指定AmazonECwClient构造函数，并使用扩展方法指定enum（如果可能的话）。

我想实现和替换我的枚举。

    public enum AwsRegion
    {
        /// <summary>The US East (Virginia) endpoint.</summary>
        USEast1 = 1,
        /// <summary>The US East (Ohio) endpoint.</summary>
        USEast2 = 2,
        /// <summary>The US West (N. California) endpoint.</summary>
        USWest1 = 3,
        /// <summary>The US West (Oregon) endpoint.</summary>
        USWest2 = 4,
        /// <summary>The EU West (Ireland) endpoint.</summary>
        EUWest1 = 5,
        /// <summary>The EU Central (Frankfurt) endpoint.</summary>
        EUCentral1 = 6,
        /// <summary>The Asia Pacific (Tokyo) endpoint.</summary>
        APNortheast1 = 7,
        /// <summary>The Asia Pacific (Seoul) endpoint.</summary>
        APNortheast2 = 8,
        /// <summary>The Asia Pacific (Mumbai) endpoint.</summary>
        APSouth1 = 9,
        /// <summary>The Asia Pacific (Singapore) endpoint.</summary>
        APSoutheast1 = 10,
        /// <summary>The Asia Pacific (Sydney) endpoint.</summary>
        APSoutheast2 = 11,
        /// <summary>The South America (Sao Paulo) endpoint.</summary>
        SAEast1 = 12,
        /// <summary>The US GovCloud West (Oregon) endpoint.</summary>
        USGovCloudWest1 = 13,
        /// <summary>The China (Beijing) endpoint.</summary>
        CNNorth1 = 14
    }

Answer 1

我认为这个源码的 aws-sdk-net RegionEndpoint.cs 将帮助你处理区域映射。

甚至 AWSSDK 有一个字典，以便快速地将一个区域字符串转换为其静态的 区域端点 对象。

private static Dictionary<string, RegionEndpoint> _hashBySystemName = new Dictionary<string, RegionEndpoint>(StringComparer.OrdinalIgnoreCase);

 /// <summary>
/// Gets the region based on its system name like "us-west-1"
/// </summary>
/// <param name="systemName">The system name of the service like "us-west-1"</param>
/// <returns></returns>
public static RegionEndpoint GetBySystemName(string systemName)
{
// ...skip
    if (_hashBySystemName.TryGetValue(systemName, out regionEndpoint))
        return regionEndpoint;
// ...skip    
}

这意味着你可以拥有自己的字典和转换方法。

private static Dictionary<AwsRegion, RegionEndpoint> _awsRegionDict = new Dictionary<AwsRegion, RegionEndpoint>(StringComparer.OrdinalIgnoreCase);

public static RegionEndpoint ConvertByAwsRegion(AwsRegion emAwsRegion)
{
    if (_awsRegionDict.TryGetValue(emAwsRegion, out regionEndpoint))
        return regionEndpoint;

    return RegionEndpoint.EUWest1; // your default region
}

提供另一个扩展方法会使它更容易使用。

public static class RegionEndpointExtension
{
    public RegionEndpoint ToRegionEndpoint(this AwsRegion region)
    {
        return AwsRegionProvider.ConvertByAwsRegion(region)
    }
}

因此，使用你的 AwsRegion enum作为第三个参数，然后调用 ConvertByAwsRegion 或 ToRegionEndpoint 按需转换法。