C# XamlObjectReader.ReadSubtree方法代码示例

		public void ReadSubtree3 ()
		{
			var xr = new XamlObjectReader (5);
			xr.Read ();
			xr.Read ();
			var sr = xr.ReadSubtree ();
			Assert.AreEqual (XamlNodeType.None, sr.NodeType, "#1-2");
			Assert.AreEqual (XamlNodeType.StartObject, xr.NodeType, "#1-3");
			Assert.IsTrue (sr.Read (), "#2");
			Assert.AreEqual (XamlNodeType.StartObject, sr.NodeType, "#2-2");
			Assert.AreEqual (XamlNodeType.StartObject, xr.NodeType, "#2-3");
			Assert.IsTrue (sr.Read (), "#3");
			Assert.AreEqual (XamlNodeType.StartMember, sr.NodeType, "#3-2");
			Assert.AreEqual (XamlNodeType.StartMember, xr.NodeType, "#3-3");
			Assert.IsTrue (sr.Read (), "#4");
			Assert.AreEqual (XamlNodeType.Value, sr.NodeType, "#4-2");
			Assert.AreEqual (XamlNodeType.Value, xr.NodeType, "#4-3");
			Assert.IsTrue (sr.Read (), "#5");
			Assert.AreEqual (XamlNodeType.EndMember, sr.NodeType, "#5-2");
			Assert.AreEqual (XamlNodeType.EndMember, xr.NodeType, "#5-3");
			Assert.IsTrue (sr.Read (), "#6");
			Assert.AreEqual (XamlNodeType.EndObject, sr.NodeType, "#6-2");
			Assert.AreEqual (XamlNodeType.EndObject, xr.NodeType, "#6-3");
			Assert.IsFalse (sr.Read (), "#7");
			Assert.AreEqual (XamlNodeType.None, xr.NodeType, "#7-2");
		}

		public void ReadSubtree1 ()
		{
			var xr = new XamlObjectReader (5);
			var sr = xr.ReadSubtree ();
			Assert.AreEqual (XamlNodeType.None, sr.NodeType, "#1-2");
			Assert.AreEqual (XamlNodeType.None, xr.NodeType, "#1-3");
			Assert.IsTrue (sr.Read (), "#2");
			Assert.AreEqual (XamlNodeType.None, sr.NodeType, "#2-2");
			Assert.AreEqual (XamlNodeType.None, xr.NodeType, "#2-3");
			Assert.IsFalse (sr.Read (), "#3");
			Assert.AreEqual (XamlNodeType.NamespaceDeclaration, xr.NodeType, "#3-2");
		}

        // This method collects view state attached properties and generates a Xaml node stream 
        // with all view state information appearing within the ViewStateManager node. 
        // It is called when workflow definition is being serialized to string.
        // inputReader  - Nodestream with view state information as attached properties on the activity nodes.
        //                The reader is positioned at the begining of the workflow definition.
        // idManager    - This component issues running sequence numbers for IdRef.
        // Result       - Node stream positioned at the begining of the workflow definition with a  
        //                ViewStateManager node containing all view state information.
        // Implementation logic:
        // 1. Scan the input nodestream Objects for attached properties that need to be converted (VirtualizedContainerService.HintSize and WorkflowViewStateService.ViewState).
        // 2. If the Object had a IdRef value then use it otherwise generate a new value.
        // 3. Store idRef value and corresponding viewstate related attached property nodes (from step 1) 
        //    in the viewStateInfo dictionary.
        // 4. Use the viewStateInfo dictionary to generate ViewStateManager node which is then inserted
        //    into the end of output nodestream.
        public static XamlReader ConvertAttachedPropertiesToViewState(XamlObjectReader inputReader, ViewStateIdManager idManager)
        {
            // Stack to track StartObject/GetObject and EndObject nodes.
            Stack<Frame> stack = new Stack<Frame>();

            XamlMember viewStateManager = new XamlMember(ViewStateManager, GetViewStateManager, SetViewStateManager, inputReader.SchemaContext);
            XamlMember idRefMember = new XamlMember(IdRef, GetIdRef, SetIdRef, inputReader.SchemaContext);
            
            // Xaml member corresponding to x:Class property of the workflow definition. Used to find x:Class value in the node stream.
            XamlMember activityBuilderName = new XamlMember(typeof(ActivityBuilder).GetProperty("Name"), inputReader.SchemaContext);
            string activityBuilderTypeName = typeof(ActivityBuilder).Name;

            // Dictionary to keep track of IdRefs and corresponding viewstate related
            // attached property nodes.
            Dictionary<string, XamlNodeList> viewStateInfo = new Dictionary<string, XamlNodeList>();

            // Output node list
            XamlNodeList workflowDefinition = new XamlNodeList(inputReader.SchemaContext);

            using (XamlWriter workflowDefinitionWriter = workflowDefinition.Writer)
            {
                bool design2010NamespaceFound = false;
                bool inIdRefMember = false;
                bool inxClassMember = false;
                bool skipWritingWorkflowDefinition = false;
                bool skipReadingWorkflowDefinition = false;
                string xClassName = null;

                while (skipReadingWorkflowDefinition || inputReader.Read())
                {
                    skipWritingWorkflowDefinition = false;
                    skipReadingWorkflowDefinition = false;
                    switch (inputReader.NodeType)
                    {
                        case XamlNodeType.NamespaceDeclaration:
                            if (inputReader.Namespace.Namespace.Equals(NameSpaces.Design2010, StringComparison.Ordinal))
                            {
                                design2010NamespaceFound = true;
                            }
                            break;

                        case XamlNodeType.StartObject:
                            // Save the Xaml type and clr object on the stack frame. These are used later to generate 
                            // IdRef values and attaching the same to the clr object.
                            stack.Push(new Frame() { Type = inputReader.Type, InstanceObject = inputReader.Instance });

                            // If the design2010 namespace was not found add the namespace node
                            // before the start object is written out.
                            if (!design2010NamespaceFound)
                            {
                                workflowDefinitionWriter.WriteNamespace(new NamespaceDeclaration(NameSpaces.Design2010, NameSpaces.Design2010Prefix));
                                design2010NamespaceFound = true;
                            }
                            break;

                        case XamlNodeType.GetObject:
                            // Push an empty frame to balance the Pop operation when the EndObject node 
                            // is encountered.
                            stack.Push(new Frame() { Type = null });
                            break;

                        case XamlNodeType.StartMember:
                            // Track when we enter IdRef member so that we can save its value.
                            if (inputReader.Member.Equals(idRefMember))
                            {
                                inIdRefMember = true;
                            }
                            // Track when we enter x:Class member so that we can save its value.
                            else if (inputReader.Member.Equals(activityBuilderName))
                            {
                                inxClassMember = true;
                            }
                            // Start of VirtualizedContainerService.HintSize or WorkflowViewStateService.ViewState property.
                            else if (IsAttachablePropertyForConvert(inputReader)) 
                            {
                                // The top of stack here corresponds to the activity on which
                                // the above properties are attached.
                                if (stack.Peek().AttachedPropertyNodes == null)
                                {
                                    stack.Peek().AttachedPropertyNodes = new XamlNodeList(inputReader.SchemaContext);
                                }

                                // Write the attached property's xaml nodes into the stack.
                                XamlReader subTreeReader = inputReader.ReadSubtree();
                                XamlWriter attachedPropertyWriter = stack.Peek().AttachedPropertyNodes.Writer;
//.........这里部分代码省略.........

        // This method removes IdRef nodes from the nodestream. This method would be called
        // when a 4.5 workflow definition is retargeted to 4.0.
        public static XamlReader RemoveIdRefs(XamlObjectReader inputReader)
        {
            XamlMember idRefMember = new XamlMember(IdRef, GetIdRef, SetIdRef, inputReader.SchemaContext);

            XamlNodeList outputNodeList = new XamlNodeList(inputReader.SchemaContext);
            using (XamlWriter outputWriter = outputNodeList.Writer)
            {
                while (inputReader.Read())
                {
                    if (inputReader.NodeType == XamlNodeType.StartMember && inputReader.Member.Equals(idRefMember))
                    {
                        // Exhaust the idRefMember sub-tree.
                        XamlReader idRefReader = inputReader.ReadSubtree();
                        while (idRefReader.Read());
                    }
                    outputWriter.WriteNode(inputReader);
                }
            }
            return outputNodeList.GetReader();
        }