System.Management.Automation.CmdletInfo.GetParameterSetInfo C# (CSharp) Method

        private static ReadOnlyCollection<CommandParameterSetInfo> GetParameterSetInfo(Type cmdletType)
        {
            Dictionary<string, Collection<CommandParameterInfo>> paramSets = new Dictionary<string, Collection<CommandParameterInfo>>(StringComparer.CurrentCultureIgnoreCase);

            // TODO: ensure there are no duplicate named parameters inside scope of a single parameter set.
            // TOOD: When using parameter sets, no parameter set should contain more than one positional parameter with the same position.
            // TODO: only one parameter in a set should declare ValueFromPipeline = true. Multiple parameters may define ValueFromPipelineByPropertyName = true.

            // Add fields with ParameterAttribute
            foreach (FieldInfo filedInfo in cmdletType.GetFields(BindingFlags.Public | BindingFlags.Instance))
            {
                System.Diagnostics.Debug.WriteLine(filedInfo.ToString());

                object[] attributes = filedInfo.GetCustomAttributes(false);

                // Find all [Parameter] attributes on the property
                ParameterAttribute paramAttr = null;
                foreach (object attr in attributes)
                {
                    if (attr is ParameterAttribute)
                    {
                        paramAttr = (ParameterAttribute)attr;

                        CommandParameterInfo pi = new CommandParameterInfo(filedInfo, filedInfo.FieldType, paramAttr);

                        string paramSetName = paramAttr.ParameterSetName ?? ParameterAttribute.AllParameterSets;

                        if (!paramSets.ContainsKey(paramSetName))
                        {
                            paramSets.Add(paramSetName, new Collection<CommandParameterInfo>());
                        }

                        Collection<CommandParameterInfo> paramSet = paramSets[paramSetName];
                        paramSet.Add(pi);
                    }
                }
            }

            // Add properties with ParameterAttribute
            foreach (PropertyInfo filedInfo in cmdletType.GetProperties(BindingFlags.Public | BindingFlags.Instance))
            {
                System.Diagnostics.Debug.WriteLine(filedInfo.ToString());

                object[] attributes = filedInfo.GetCustomAttributes(false);

                // Get info for the setter and getter
                MethodInfo getter = filedInfo.GetAccessors().FirstOrDefault(i => i.IsSpecialName && i.Name.StartsWith("get_"));
                MethodInfo setter = filedInfo.GetSetMethod();

                // Find all [Parameter] attributes on the property
                ParameterAttribute paramAttr = null;
                foreach (object attr in attributes)
                {
                    if (attr is ParameterAttribute)
                    {
                        paramAttr = (ParameterAttribute)attr;

                        // if ValueFromPipeline or ValueFromPipelineByPropertyName is specified the property must have a public getter
                        if ((paramAttr.ValueFromPipeline || paramAttr.ValueFromPipelineByPropertyName) && (getter == null || !getter.IsPublic))
                        {
                            break;
                        }

                        // The property must have a public setter
                        if (setter == null || !setter.IsPublic)
                        {
                            break;
                        }

                        CommandParameterInfo pi = new CommandParameterInfo(filedInfo, filedInfo.PropertyType, paramAttr);

                        string paramSetName = paramAttr.ParameterSetName ?? ParameterAttribute.AllParameterSets;

                        if (!paramSets.ContainsKey(paramSetName))
                        {
                            paramSets.Add(paramSetName, new Collection<CommandParameterInfo>());
                        }

                        Collection<CommandParameterInfo> paramSet = paramSets[paramSetName];
                        paramSet.Add(pi);
                    }
                }
            }

            // Create param-sets collection
            Collection<CommandParameterSetInfo> paramSetInfo = new Collection<CommandParameterSetInfo>();

            // TODO: find the name of the default param set
            string strDefaultParameterSetName = ParameterAttribute.AllParameterSets;
            object[] cmdLetAttrs = cmdletType.GetCustomAttributes(typeof(CmdletAttribute), false);
            if (cmdLetAttrs.Length > 0)
                strDefaultParameterSetName = ((CmdletAttribute)cmdLetAttrs[0]).DefaultParameterSetName ?? strDefaultParameterSetName;

            foreach (string paramSetName in paramSets.Keys)
            {
                bool bIsDefaultParamSet = paramSetName == strDefaultParameterSetName;

                paramSetInfo.Add(new CommandParameterSetInfo(paramSetName, bIsDefaultParamSet, paramSets[paramSetName]));

                // If a parameter set is not specified for a parmeter, then the parameter belongs to all the parameter sets,
                // therefore if this is not the AllParameterSets Set then add all parameters from the AllParameterSets Set to it...
                if (string.Compare(paramSetName, ParameterAttribute.AllParameterSets) != 0 && paramSets.ContainsKey(ParameterAttribute.AllParameterSets))
                {
                    foreach (CommandParameterInfo cpi in paramSets[ParameterAttribute.AllParameterSets])
                    {
                        paramSets[paramSetName].Add(cpi);
                    }
                }
            }

            return new ReadOnlyCollection<CommandParameterSetInfo>(paramSetInfo);
        }