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对象化数据---学习Xml Serialization的一些体会

技术开发2022-05-04阅读
刚接触.net时,就看到过一些用到Xml Serialization的例子,当时没什么感觉。后来看了SDK和一些较大的程序后,逐渐有了点感觉。我个人感觉Xml Serialization 的最大好处是可以将一个xml文件对象化,比如说xml中的元素、属性等都可以对应到对象、对象的属性。这样我们可以用对象的思想来操作数据,由于目前主流数据库还只是关系型的(Oracle也只是部分面向对象),我们在数据层的操作显得于其他层面有点隔。而Xml Serialization给了我们这样一个用面向对象的思维来操作数据的可能。据个例子来说,比如说我们要做一个制作工作流程的程序,每个流程有n个阶段,每个阶段有n个人来完成。如果用数据库做,就不可避免的涉及到多表关联。这对于这样一个数据量比较小的程序来说是一个浪费。我们来看一下怎么利用xml来做。

///示例xml文件
<?xml version="1.0"?>
<WorkflowData xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance" xmlns:xsd="http://www.w3.org/1999/XMLSchema">
<workflows>
<workflow name="请假流程" id="1">
<stages>
<stage name="主管核准" id="1" ordernum="1">
<users>
<user name="James" isAudit="1"/>
</users>
</stage>
</stages>
</workflow>
</workflows>
</WorkflowConfigData>

///示例cs文件
using System;
using System.Collections;
using System.IO;
using System.Text;
using System.Web;
using System.Xml.Serialization;

namespace Portal.Modules.Workflow
{
public class WorkflowConfig
{
public static WorkflowData Settings
{
get
{
HttpContext context = HttpContext.Current;
WorkflowData data = (WorkflowData) context.Cache["workflowconfig"];
if (data == null)
{
data = LoadSettings(WorkflowConfig.ConfigFilePath);
context.Cache.Insert("workflowconfig", data, new CacheDependency(WorkflowConfig.ConfigFilePath));
}
}
}

public static String ConfigFilePath
{
get
{
HttpContext context = HttpContext.Current;
return context.Server.MapPath(context.Request.ApplicationPath + "//" + "Workflow//workflow.xml");
}
}

public static WorkflowData LoadSettings(String fileName)
{
StreamReader reader = File.OpenText(fileName);
XmlSerializer serializer = new XmlSerializer(typeof(WorkflowData));
WorkflowData data = (WorkflowData)serializer.Deserialize(reader);
reader.Close();
return data;
}

public static void PersistSettings(WorkflowData data)
{
HttpContext context = HttpContext.Current;
String configFilePath = context.Server.MapPath(context.Request.ApplicationPath + "//Workflow//workflow.xml");
StreamWriter writer = File.CreateText(configFilePath);
XmlSerializer serializer = new XmlSerializer(typeof(WorkflowData));
serializer.Serialize(writer, data);
writer.Close();
}
}

public class WorkflowData
{
private Workflow[] _workflows;

[XmlArray]
public Workflow [] Workflows
{
get
{
return _workflows;
}
set
{
_workflows = value;
}
}

[XmlIgnore]
public Workflow this[int workflowID]
{
get
{
foreach(Workflow workflow in Workflows)
{
if(workflowID == workflow.ID)
{
return workflow;
}
}
return null;
}
}
}

public class Workflow
{
private String_name;
private int_id;
private Stage []_stages;

[XmlAttribute]
public String Name
{
get
{
return _name;
}
set
{
_name = value;
}
}

[XmlAttribute]
public int ID
{
get
{
return _id;
}
set
{
_id = value;
}
}

[XmlArray]
public Stage [] Stages
{
get
{
return _stages;
}
set
{
_stages = value;
}
}

[XmlIgnore]
public Stage this[int stageid]
{
get
{
foreach(Stage stage in Stages)
{
if(stageid == stage.ID)
{
return stage;
}
}
return null;
}
}
}

public class Stage
{
private int_id;
private String_name;
private int_orderNum;
private User []_users;

[XmlAttribute]
public String Name
{
get
{
return _name;
}
set
{
_name = value;
}
}

[XmlAttribute]
public int ID
{
get
{
return _id;
}
set
{
_id = value;
}
}

[XmlAttribute]
public int OrderNum
{
get
{
return _orderNum;
}
set
{
_orderNum = value;
}
}

[XmlArray]
public User [] Users
{
get
{
return _users;
}
set
{
_users = value;
}
}
}

public class User
{
private bool_isAudit;
private String_name;

public bool IsAudit
{
get
{
return _isAudit;
}
set
{
_isAudit = value;
}
}

public String Name
{
get
{
return _name;
}
set
{
_name = value;
}
}
}
}
这样我们可以这样来操作数据
workflow[0].stages[0].user[0] //得到用户
类似的我就不说了。(上面的代码不可以直接使用,由于涉及到公司,我删了许多,只是演示而已)
这只是小弟的愚见,还望各位大虾指正

……

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