System.Xml.Schema.SchemaInfo.GetAttributeXsd C# (CSharp) Method

        public SchemaAttDef GetAttributeXsd(SchemaElementDecl ed, XmlQualifiedName qname, XmlSchemaObject partialValidationType, out AttributeMatchState attributeMatchState) {
            SchemaAttDef attdef = null;
            attributeMatchState = AttributeMatchState.UndeclaredAttribute;
            if (ed != null) {
                attdef = ed.GetAttDef(qname);
                if (attdef != null) {
                    attributeMatchState = AttributeMatchState.AttributeFound;
                    return attdef;
                }
                XmlSchemaAnyAttribute any = ed.AnyAttribute;
                if (any != null) {
                    if (!any.NamespaceList.Allows(qname)) {
                        attributeMatchState = AttributeMatchState.ProhibitedAnyAttribute;
                    }
                    else if (any.ProcessContentsCorrect != XmlSchemaContentProcessing.Skip) {
                        attdef = (SchemaAttDef)attributeDecls[qname];
                        if (attdef != null) {
                            if (attdef.Datatype.TypeCode == XmlTypeCode.Id) { //anyAttribute match whose type is ID
                                attributeMatchState = AttributeMatchState.AnyIdAttributeFound;
                            }
                            else {
                                attributeMatchState = AttributeMatchState.AttributeFound;
                            }
                        }
                        else if (any.ProcessContentsCorrect == XmlSchemaContentProcessing.Lax) {
                            attributeMatchState = AttributeMatchState.AnyAttributeLax;
                        }
                    }
                    else {
                        attributeMatchState = AttributeMatchState.AnyAttributeSkip;
                    }
                }
                else if (ed.ProhibitedAttributes[qname] != null) {
                    attributeMatchState = AttributeMatchState.ProhibitedAttribute;
                }
            }
            else if (partialValidationType != null) {
                XmlSchemaAttribute attr = partialValidationType as XmlSchemaAttribute;
                if (attr != null) {
                    if (qname.Equals(attr.QualifiedName)) {
                        attdef = attr.AttDef;
                        attributeMatchState = AttributeMatchState.AttributeFound;
                    }
                    else {
                        attributeMatchState = AttributeMatchState.AttributeNameMismatch;
                    }
                }
                else {
                    attributeMatchState = AttributeMatchState.ValidateAttributeInvalidCall;
                }
            }
            else {
                attdef = (SchemaAttDef)attributeDecls[qname];
                if (attdef != null) {
                    attributeMatchState = AttributeMatchState.AttributeFound;
                }
                else {
                    attributeMatchState = AttributeMatchState.UndeclaredElementAndAttribute;
                }
            }
            return attdef;
        }