开发自定义InstanceStore - 错误 [英] Developing of a custom InstanceStore - Errors

问题描述

您好，

解决方案

您好Zeljko，

.NET 4 SDK PurchaseProcess示例包含一个简单的基于XML的实例存储，可以回答你的一些问题。

希望现在有所帮助，

Ruppert

 

 

// --------------- -------------------------------------------------- ------------
//版权所有（c）Microsoft Corporation。 保留所有权利。
// ---------------------------------------- -------------------------------------

使用System ;
使用System.Activities.DurableInstancing;
使用System.Collections.Generic;
使用System.IO;
使用System.Runtime.DurableInstancing;
使用System。 Runtime.Serialization;
使用System.ServiceModel.Persistence;
使用System.Xml;
使用System.Xml.Linq;

命名空间Microsoft.Samples .WF.PurchaseProcess
{{/ />

   公共类XmlWorkflowInstanceStore：InstanceStore
    {
        Guid ownerInstanceID;
       
        public XmlWorkflowInstanceStore（）：this（Guid.NewGuid（））
        {

        }

        public XmlWorkflowInstanceStore（Guid id）
        {
            ownerInstanceID = id;
        }

        // Begin / EndTryCommand函数的同步版本        protected override bool TryCommand（InstancePersistenceContext context，InstancePersistenceCommand命令，TimeSpan超时）
        {
            return EndTryCommand（BeginTryCommand（context，command，timeout，null，null））;
        }

        //持久性引擎将向配置的InstanceStore发送各种命令，        //例如CreateWorkflowOwnerCommand，SaveWorkflowCommand和LoadWorkflowCommand。
        //此方法是我们处理这些命令的方法
        protected override IAsyncResult BeginTryCommand（InstancePersistenceContext context，InstancePersistenceCommand命令，TimeSpan超时，AsyncCallback回调，对象状态）
        {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; IDictionary< XName，InstanceValue> data = null;

            // CreateWorkflowOwner命令指示实例存储创建绑定到instanace句柄的新实例所有者
            if（命令为CreateWorkflowOwnerCommand）
            {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; context.BindInstanceOwner（ownerInstanceID，Guid.NewGuid（））;
            }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; // SaveWorkflow命令指示实例存储修改绑定到实例句柄或实例密钥的实例
            else if（命令是SaveWorkflowCommand）
            {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; SaveWorkflowCommand saveCommand =（SaveWorkflowCommand）命令;
                data = saveCommand.InstanceData;

               保存（数据）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; // LoadWorkflow命令指示实例存储锁定并加载绑定到实例句柄中标识符的实例
            else if（命令是LoadWorkflowCommand）
            {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;字符串文件名= IOHelper.GetFileName（this.ownerInstanceID）;

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;尝试
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;使用（的FileStream的inputStream =新的FileStream（文件名，FileMode.Open））
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;&NBSP;&NBSP; {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;数据= LoadInstanceDataFromFile（的inputStream）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;&NBSP;&NBSP; //将数据加载到持久性上下文中                    ;&NBSP;&NBSP;&NBSP;&NBSP; context.LoadedInstance（InstanceState.Initialized，数据，NULL，NULL，NULL）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;&NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; catch（例外例外）
                {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;抛出新的PersistenceException（exception.Message）;
                }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; }

           返回新的CompletedAsyncResult< bool>（true，callback，state）;
        }

       受保护的覆盖bool EndTryCommand（IAsyncResult结果）
        {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; return CompletedAsyncResult< bool> .End（result）;
        }

        //从xml文件中读取数据并根据该文件创建字典。
        IDictionary< XName，InstanceValue> LoadInstanceDataFromFile（Stream inputStream）
        {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; IDictionary< XName，InstanceValue> data = new Dictionary< XName，InstanceValue>（）;

            NetDataContractSerializer s = new NetDataContractSerializer（）;

            XmlReader rdr = XmlReader.Create（inputStream）;
            XmlDocument doc = new XmlDocument（）;
            doc.Load（rdr）;

            XmlNodeList instances = doc.GetElementsByTagName（" InstanceValue"）;
            foreach（实例中的XmlElement instanceElement）
            {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;的XmlElement keyElement =（的XmlElement）instanceElement.SelectSingleNode（QUOT;后代::密钥QUOT）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;的XName密钥=（的XName）DeserializeObject（S，keyElement）;

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;的XmlElement valueElement =（的XmlElement）instanceElement.SelectSingleNode（QUOT;后代::值QUOT）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP; object value = DeserializeObject（s，valueElement）;
                InstanceValue instVal =新InstanceValue（值）;

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; data.Add（key，instVal）;
            }

           返回数据;
        }

        object DeserializeObject（NetDataContractSerializer序列化程序，XmlElement元素）
        {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; object deserializedObject = null;

            MemoryStream stm = new MemoryStream（）;
            XmlDictionaryWriter wtr = XmlDictionaryWriter.CreateTextWriter（stm）;
            element.WriteContentTo（WTR）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; wtr.Flush（）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; stm.Position = 0;

            deserializedObject = serializer.Deserialize（stm）;

            return deserializedObject;
        }

        //将持久性数据保存到xml文件。
        void保存（IDictionary< XName，InstanceValue> instanceData）
        {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; string fileName = IOHelper.GetFileName（this.ownerInstanceID）;
            XmlDocument doc = new XmlDocument（）;
            doc.LoadXml（QUOT;< InstanceValues />"）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; foreach（KeyValuePair< XName，InstanceValue> instanceData中的valPair）
            {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;的XmlElement的newInstance = doc.CreateElement（QUOT; InstanceValue"）;

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;的XmlElement则newkey = SerializeObject（QUOT;键" ;, valPair.Key，DOC）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ; newInstance.AppendChild（newKey）;

               的XmlElement NEWVALUE = SerializeObject（QUOT;值" ;, valPair.Value.Value，DOC）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP; newInstance.AppendChild（NEWVALUE）;

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; doc.DocumentElement.AppendChild（的newInstance）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; doc.Save（文件名）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; }

        XmlElement SerializeObject（string elementName，object o，XmlDocument doc）
        {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; NetDataContractSerializer s = new NetDataContractSerializer（）;
            XmlElement newElement = doc.CreateElement（elementName）;
            MemoryStream stm = new MemoryStream（）;

            s.Serialize（stm，o）;
            stm.Position = 0;
            StreamReader rdr = new StreamReader（stm）;
            newElement.InnerXml = rdr.ReadToEnd（）;

            return newElement;
        }
&NBSP;&NBSP;&NBSP; }}

Hi there,

解决方案

Hi Zeljko,

the .NET 4 SDK PurchaseProcess sample contains a simple XML-based instance store, which might answer some of your questions.

Hope that helps for now,

Ruppert

 

 

//-----------------------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

using System;
using System.Activities.DurableInstancing;
using System.Collections.Generic;
using System.IO;
using System.Runtime.DurableInstancing;
using System.Runtime.Serialization;
using System.ServiceModel.Persistence;
using System.Xml;
using System.Xml.Linq;

namespace Microsoft.Samples.WF.PurchaseProcess
{

    public class XmlWorkflowInstanceStore : InstanceStore
    {
        Guid ownerInstanceID;
       
        public XmlWorkflowInstanceStore() : this(Guid.NewGuid())
        {

        }

        public XmlWorkflowInstanceStore(Guid id)
        {
            ownerInstanceID = id;
        }

        //Synchronous version of the Begin/EndTryCommand functions
        protected override bool TryCommand(InstancePersistenceContext context, InstancePersistenceCommand command, TimeSpan timeout)
        {
            return EndTryCommand(BeginTryCommand(context, command, timeout, null, null));
        }

        //The persistence engine will send a variety of commands to the configured InstanceStore,
        //such as CreateWorkflowOwnerCommand, SaveWorkflowCommand, and LoadWorkflowCommand.
        //This method is where we will handle those commands
        protected override IAsyncResult BeginTryCommand(InstancePersistenceContext context, InstancePersistenceCommand command, TimeSpan timeout, AsyncCallback callback, object state)
        {
            IDictionary<XName, InstanceValue> data = null;

            //The CreateWorkflowOwner command instructs the instance store to create a new instance owner bound to the instanace handle
            if (command is CreateWorkflowOwnerCommand)
            {
                context.BindInstanceOwner(ownerInstanceID, Guid.NewGuid());
            }
            //The SaveWorkflow command instructs the instance store to modify the instance bound to the instance handle or an instance key
            else if (command is SaveWorkflowCommand)
            {
                SaveWorkflowCommand saveCommand = (SaveWorkflowCommand)command;
                data = saveCommand.InstanceData;

                Save(data);
            }
            //The LoadWorkflow command instructs the instance store to lock and load the instance bound to the identifier in the instance handle
            else if (command is LoadWorkflowCommand)
            {
                string fileName = IOHelper.GetFileName(this.ownerInstanceID);

                try
                {
                    using (FileStream inputStream = new FileStream(fileName, FileMode.Open))
                    {
                        data = LoadInstanceDataFromFile(inputStream);
                        //load the data into the persistence Context
                        context.LoadedInstance(InstanceState.Initialized, data, null, null, null);
                    }
                }
                catch (Exception exception)
                {
                    throw new PersistenceException(exception.Message);
                }
            }

            return new CompletedAsyncResult<bool>(true, callback, state);
        }

        protected override bool EndTryCommand(IAsyncResult result)
        {
            return CompletedAsyncResult<bool>.End(result);
        }

        //Reads data from xml file and creates a dictionary based off of that.
        IDictionary<XName, InstanceValue> LoadInstanceDataFromFile(Stream inputStream)
        {
            IDictionary<XName, InstanceValue> data = new Dictionary<XName, InstanceValue>();

            NetDataContractSerializer s = new NetDataContractSerializer();

            XmlReader rdr = XmlReader.Create(inputStream);
            XmlDocument doc = new XmlDocument();
            doc.Load(rdr);

            XmlNodeList instances = doc.GetElementsByTagName("InstanceValue");
            foreach (XmlElement instanceElement in instances)
            {
                XmlElement keyElement = (XmlElement)instanceElement.SelectSingleNode("descendant::key");
                XName key = (XName)DeserializeObject(s, keyElement);

                XmlElement valueElement = (XmlElement)instanceElement.SelectSingleNode("descendant::value");
                object value = DeserializeObject(s, valueElement);
                InstanceValue instVal = new InstanceValue(value);

                data.Add(key, instVal);
            }

            return data;
        }

        object DeserializeObject(NetDataContractSerializer serializer, XmlElement element)
        {
            object deserializedObject = null;

            MemoryStream stm = new MemoryStream();
            XmlDictionaryWriter wtr = XmlDictionaryWriter.CreateTextWriter(stm);
            element.WriteContentTo(wtr);
            wtr.Flush();
            stm.Position = 0;

            deserializedObject = serializer.Deserialize(stm);

            return deserializedObject;
        }

        //Saves the persistance data to an xml file.
        void Save(IDictionary<XName, InstanceValue> instanceData)
        {
            string fileName = IOHelper.GetFileName(this.ownerInstanceID);
            XmlDocument doc = new XmlDocument();
            doc.LoadXml("<InstanceValues/>");
           
            foreach (KeyValuePair<XName,InstanceValue> valPair in instanceData)
            {
                XmlElement newInstance = doc.CreateElement("InstanceValue");

                XmlElement newKey = SerializeObject("key", valPair.Key, doc);
                newInstance.AppendChild(newKey);

                XmlElement newValue = SerializeObject("value", valPair.Value.Value, doc);
                newInstance.AppendChild(newValue);

                doc.DocumentElement.AppendChild(newInstance);
            }
            doc.Save(fileName);
       }

        XmlElement SerializeObject(string elementName, object o, XmlDocument doc)
        {
            NetDataContractSerializer s = new NetDataContractSerializer();
            XmlElement newElement = doc.CreateElement(elementName);
            MemoryStream stm = new MemoryStream();

            s.Serialize(stm, o);
            stm.Position = 0;
            StreamReader rdr = new StreamReader(stm);
            newElement.InnerXml = rdr.ReadToEnd();

            return newElement;
        }
    }
}

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