System.Xml.Xsl.XsltContext.ResolveVariable C# (CSharp) Méthode

        public abstract IXsltContextVariable ResolveVariable(string prefix, string name);
        public abstract IXsltContextFunction ResolveFunction(string prefix, string name, XPathResultType[] ArgTypes);

        internal override void SetXsltContext(XsltContext context) {
            if (context == null) {
                throw new XPathException(Res.Xp_UndefinedXsltContext, Prefix, Name);            }

            if(xsltContextVariable == null) {
                xsltContextVariable = context.ResolveVariable(Prefix, Name);
                Debug.Assert(xsltContextVariable != null, "XSLT has to resolve it or throw exception");
            }
            else {
                Debug.Assert(xsltContextVariable == context.ResolveVariable(Prefix, Name), "ResolveVariable supposed to return the same VariableAction each time");
            }
            Object result = xsltContextVariable.Evaluate(context);
            if (result is double) {
                _VarQuery = new OperandQuery(result, XPathResultType.Number);
            }
            else if (result is String) {
                _VarQuery = new OperandQuery(result, XPathResultType.String);
            }
            else if (result is Boolean) {
                _VarQuery = new OperandQuery(result, XPathResultType.Boolean);
            }
            else if (result is XPathNavigator) {
                _VarQuery = new NavigatorQuery((XPathNavigator)result);
            }            
            else if (result is ResetableIterator) {
                ResetableIterator it = result as ResetableIterator;
                _VarQuery = new XmlIteratorQuery( (ResetableIterator) it.Clone() );
            }
            else if (result is XPathNodeIterator) {
                Debug.Assert(false, "Unexpected type of XPathNodeIterator");
                throw new NotSupportedException(Res.GetString(Res.XmlUnsupportedType, result.GetType().FullName));             
            }
            else if (result is int) {
                _VarQuery = new OperandQuery(XmlConvert.ToXPathDouble(result), XPathResultType.Number);
            }
            else {
                if (result == null) {
                    throw new XPathException(Res.Xslt_InvalidVariable, Name);
                }
                Debug.Assert(false, "Unexpected variable type");
                throw new NotSupportedException(Res.GetString(Res.XmlUnsupportedType, result.GetType().FullName));
            }
            Debug.Assert(_VarQuery != null);           
        }