C#获取yaml文件中父节点buildRelease下所有子节点为releaseID的值以及兄弟节点buildEnvironment下所有子节点为buildSystem，

在C#中，如果你需要从YAML文件中获取特定结构的数据，通常可以使用第三方库如`YamlDotNet`。首先，你需要安装这个库（如果尚未安装）：

Install-Package YamlDotNet

然后，你可以创建一个解析YAML文档并访问所需数据的类。下面是一个基本示例，假设你的YAML文件结构类似这样：

build:
  release:
    - releaseID: value1
      otherProperties: ...
    - releaseID: value2
      otherProperties: ...

buildEnvironment:
  buildSystem:
    - name: system2

你可以使用`YamlNode`类和递归方法来遍历并查找所需的值：

using YamlDotNet.Reading;
using YamlDotNet.Serialization;

public class YamlHelper
{
    public static string[] GetReleaseIdsAndBuildSystems(string yamlContent)
    {
        var loader = new SafeYamlLoader(yamlContent);
        var rootNode = loader.Load();
        
        List<string> releaseIds = new List<string>();
        List<string> buildSystems = new List<string>();

        VisitNodeRecursively(rootNode, ref releaseIds, ref buildSystems);
        
        return releaseIds.ToArray(), buildSystems.ToArray();
    }

    private static void VisitNodeRecursively(YamlNode node, ref List<string> releaseIds, ref List<string> buildSystems)
    {
        if (node is MappingNode mapping && mapping.Children.Contains("release"))
        {
            foreach (var child in mapping.Children["release"])
            {
                if (child is ScalarNode scalar && scalar.Value == "releaseID")
                    releaseIds.Add(scalar.Value);
            }
        }

        if (node is MappingNode environment && environment.Children.Contains("buildSystem"))
        {
            foreach (var child in environment.Children["buildSystem"])
            {
                if (child is ScalarNode buildSystemScalar && buildSystemScalar.Value == "name")
                    buildSystems.Add(buildSystemScalar.Value);
            }
        }

        foreach (var child in node.Children)
            VisitNodeRecursively(child, ref releaseIds, ref buildSystems);
    }
}

要使用这个帮助类，传入你的YAML内容：

string yamlContent = File.ReadAllText("your_yaml_file.yaml");
string[] result = YamlHelper.GetReleaseIdsAndBuildSystems(yamlContent);