Best .net Method to create an XML Doc_问答_开发者

I am trying to figure out what the best method is for writing an XML Document. Below is a simple example of what I am trying to create off of data I am pulling from our ERP system. I have read about XMLWriter, but thought I woul开发者_如何学JAVAd see if there are any other better methods. Any suggestions would be greatly appreciated.

Example XML:

<?xml version="1.0"?>
<Orders>
  <Order OrderNumber="12345">
    <ItemNumber>0123993587</ItemNumber>
    <QTY>10</QTY>
    <WareHouse>PA019</WareHouse>
  </Order>
  <Order OrderNumber="12346">
    <ItemNumber>0123993587</ItemNumber>
    <QTY>9</QTY>
    <WareHouse>PA019</WareHouse>
  </Order>
  <Order OrderNumber="12347">
    <ItemNumber>0123993587</ItemNumber>
    <QTY>8</QTY>
    <WareHouse>PA019</WareHouse>
  </Order>
</Orders>

Josh's answer shows how easy it is to create a single element in LINQ to XML... it doesn't show how it's also hugely easy to create multiple elements. Suppose you have a List<Order> called orders... you can create the whole document like this:

var xml = new XElement("Orders",
    orders.Select(order =>
        new XElement("Order",
            new XAttribute("OrderNumber", order.OrderNumber),
            new XElement("ItemNumber", order.ItemNumber),
            new XElement("QTY", order.Quantity),
            new XElement("Warehouse", order.Warehouse)
        )
    )
);

LINQ to XML makes constructing XML incredibly easy. It also has support for XML namespaces which is pretty easy too. For instance, if you wanted your elements to be in a particular namespace, you'd just need:

XNamespace ns = "http://your/namespace/here";
var xml = new XElement(ns + "Orders",
    orders.Select(order =>
        new XElement(ns + "Order",
... (rest of code as before)

LINQ to XML is the best XML API I've worked with... it's great for querying too.

I would suggest using the classes in System.Xml.Linq.dll which contain an XML DOM API that allows for easy build-up of XML structures due to the way the contructors are designed. Trying to create an XML structure using the System.Xml classes is very painful because you have to create them detached then separately add them into the document.

Here's an example of XLinq vs. System.Xml to create a DOM from scratch. Your eyes will bleed when you see the System.Xml example.

Here's a quick example of how you would use XLinq to build up part of your doc.

var xml = new XElement("Orders",
    new XElement("Order",
        new XAttribute("OrderNumber", 12345),
        new XElement("ItemNumber", "01234567"),
        new XElement("QTY", 10),
        new XElement("Warehouse", "PA019")
    )
);

TIP Although it's a little unorthodox (though no worse than some of the language butchering that has become popular lately), I have on occasion used C#'s type aliasing feature to minimize the code even further:

using XE = System.Xml.Linq.XElement;
using XA = System.Xml.Linq.XAttribute;
...
var xml = new XE("Orders",
    new XE("Order",
        new XA("OrderNumber", 12345),
        new XA("ItemNumber", "01234567"),
        new XA("QTY", 10),
        new XA("Warehouse", "PA019")
    )
);

What about this : create a class "Order" and one "Orders", and then serialize those out to XML - seems a lot easier to me than creating the XML bit by bit from hand....

Since you say you're pulling the data off your ERP, you probably already have objects and classes for "Order" and so on - maybe it's sufficient to put a few [XmlElement] attributes on your classes and you're good to go!

using System;
using System.Collections.Generic;
using System.Xml.Serialization;

namespace XmlLinqTest
{
    [Serializable]
    [XmlRoot(Namespace = "")]
    public class Orders
    {
        private List<Order> _orders = new List<Order>();

        /// <remarks/>
        [XmlElement("Order")]
        public List<Order> OrderList
        {
            get { return _orders; }
        }
    }

    /// <remarks/>
    [Serializable]
    public class Order
    {
        /// <remarks/>
        [XmlElement]
        public string ItemNumber { get; set; }

        [XmlElement]
        public int QTY { get; set; }

        /// <remarks/>
        [XmlElement]
        public string WareHouse { get; set; }

        /// <remarks/>
        [XmlAttribute]
        public string OrderNumber { get; set; }
    }
}

and in your main app something like this:

Orders orders = new Orders();

Order work = new Order() { ItemNumber = "0123993587", OrderNumber = "12345", QTY = 10, WareHouse = "PA019" };
orders.OrderList.Add(work);

work = new Order() { ItemNumber = "0123993587", OrderNumber = "12346", QTY = 9, WareHouse = "PA019" };
orders.OrderList.Add(work);

work = new Order() { ItemNumber = "0123993587", OrderNumber = "12347", QTY = 8, WareHouse = "PA019" };
orders.OrderList.Add(work);

XmlSerializer ser = new XmlSerializer(typeof(Orders));

using(StreamWriter wr = new StreamWriter(@"D:\testoutput.xml", false, Encoding.UTF8))
{
    ser.Serialize(wr, orders);
}

Working with objects and then serializing them out to disk seems a lot easier to me than fiddling around with XDocument and other APIs.

If your use case is simple, nothing could possibly simpler and easier to use than XmlTextWriter. That said, one alternative would be to use an XmlDocument object to create and append all of your nodes. But I think it's easier to write and maintain code that uses XmlTextWriter if you're creating a document from scratch rather than manipulating one. Using XmlTextWriter should be very straightforward:

        StringBuilder output = new StringBuilder();
        XmlWriter writer = XmlWriter.Create(output);
        writer.WriteProcessingInstruction("xml", "version=\"1.0\"");
        writer.WriteStartElement("Orders");
        //...start loop...
        writer.WriteStartElement("Order");
        writer.WriteAttributeString("OrderNumber", "12345");
        writer.WriteElementString("ItemNumber", "0123993587");
        writer.WriteElementString("QTY", "10");
        writer.WriteElementString("WareHouse", "PA019");
        writer.WriteEndElement();
        //...loop...
        writer.WriteEndElement();
        writer.Close();

There's a new language called XCST that compiles to C#.

<c:template name='c:initial-template' expand-text='yes'>
   <c:param name='orders' as='IEnumerable&lt;Order>'/>

   <Orders>
      <c:for-each name='order' in='orders'>
         <Order OrderNumber='{order.Number}'>
            <ItemNumber>{order.ItemNumber}</ItemNumber>
            <QTY>{order.Quantity}</QTY>
            <WareHouse>{order.WareHouse}</WareHouse>
         </Order>
      </c:for-each>
   </Orders>
</c:template>

I had to create following XML document having some part of it parametrized.

<?xml version="1.0" encoding="utf-8"?>
<wap-provisioningdoc>
  <characteristic type="BOOTSTRAP">
    <parm name="NAME" value="SYNCSETTINGS" />
  </characteristic>
  <characteristic type="APPLICATION">
    <parm name="APPID" value="w5" />
    <parm name="TO-NAPID" value="INTERNET" />
    <parm name="NAME" value="SYNCSETTINGS" />
    <parm name="ADDR" value="http://syncserver/sync" />
    <characteristic type="RESOURCE">
      <parm name="URI" value="pb" />
      <parm name="NAME" value="Contacts DB" />
      <parm name="AACCEPT" value="text/x-vcard" />
    </characteristic>
    <characteristic type="RESOURCE">
      <parm name="URI" value="cal" />
      <parm name="NAME" value="Calendar DB" />
      <parm name="AACCEPT" value="text/x-vcalendar" />
    </characteristic>
    <characteristic type="RESOURCE">
      <parm name="URI" value="notes" />
      <parm name="NAME" value="Notes DB" />
      <parm name="AACCEPT" value="text/plain" />
    </characteristic>
    <characteristic type="APPAUTH">
      <parm name="AAUTHNAME" value="username" />
      <parm name="AAUTHSECRET" value="password" />
    </characteristic>
  </characteristic>
</wap-provisioningdoc>

And here's my code that does this with single LINQ statement.

Make a note that creating XML document above using LINQ and saving it to XML file preserves the XML document formatting and keeps line-breaks and carriage-returns that makes the document properly tabified.

public string CreateOTAXmlFile(string Username, string Password)
    {
        var ota = new XDocument(
                    new XElement("wap-provisioningdoc",
                        new XElement("characteristic", new XAttribute("type", "BOOTSTRAP"),
                            new XElement("parm", new XAttribute("name", "NAME"), new XAttribute("value", "SYNCSETTINGS"))
                                    ),
                        new XElement("characteristic", new XAttribute("type", "APPLICATION"),
                            new XElement("parm", new XAttribute("name", "APPID"), new XAttribute("value", "w5")),
                            new XElement("parm", new XAttribute("name", "TO-NAPID"), new XAttribute("value", "INTERNET")),
                            new XElement("parm", new XAttribute("name", "NAME"), new XAttribute("value", "SYNCSETTINGS")),
                            new XElement("parm", new XAttribute("name", "ADDR"), new XAttribute("value", "http://syncserver/sync")),
                            new XElement("characteristic", new XAttribute("type", "RESOURCE"),
                                new XElement("parm", new XAttribute("name", "URI"), new XAttribute("value", "pb")),
                                new XElement("parm", new XAttribute("name", "NAME"), new XAttribute("value", "Contacts DB")),
                                new XElement("parm", new XAttribute("name", "AACCEPT"), new XAttribute("value", "text/x-vcard"))
                                        ),
                            new XElement("characteristic", new XAttribute("type", "RESOURCE"),
                                new XElement("parm", new XAttribute("name", "URI"), new XAttribute("value", "cal")),
                                new XElement("parm", new XAttribute("name", "NAME"), new XAttribute("value", "Calendar DB")),
                                new XElement("parm", new XAttribute("name", "AACCEPT"), new XAttribute("value", "text/x-vcalendar"))
                                        ),
                            new XElement("characteristic", new XAttribute("type", "RESOURCE"),
                                new XElement("parm", new XAttribute("name", "URI"), new XAttribute("value", "notes")),
                                new XElement("parm", new XAttribute("name", "NAME"), new XAttribute("value", "Notes DB")),
                                new XElement("parm", new XAttribute("name", "AACCEPT"), new XAttribute("value", "text/plain"))
                                        ),
                            new XElement("characteristic", new XAttribute("type", "APPAUTH"),
                                new XElement("parm", new XAttribute("name", "AAUTHNAME"), new XAttribute("value", Username)),
                                new XElement("parm", new XAttribute("name", "AAUTHSECRET"), new XAttribute("value", Password))
                                        )
                                    )
                                )
                            );

        ota.Save(Server.MapPath("~/OTA/") + Username + ".xml");
        return (ota.ToString());

    }

// Create the xml document containe
XmlDocument doc = new XmlDocument();// Create the XML Declaration, and append it to XML document
XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", null, null);
doc.AppendChild(dec);// Create the root element
XmlElement root = doc.CreateElement("Library");
doc.AppendChild(root);
// Create Books
// Note that to set the text inside the element,
// you use .InnerText instead of .Value (which will throw an exception).
// You use SetAttribute to set attribute
XmlElement book = doc.CreateElement("Book");
book.SetAttribute("BookType", "Hardcover");
XmlElement title = doc.CreateElement("Title");
title.InnerText = "Door Number Three";
XmlElement author = doc.CreateElement("Author");
author.InnerText = "O'Leary, Patrick";
book.AppendChild(title);
book.AppendChild(author);
root.AppendChild(book);
book = doc.CreateElement("Book");
book.SetAttribute("BookType", "Paperback");
title = doc.CreateElement("Title");
title.InnerText = "Lord of Light";
author = doc.CreateElement("Author");
author.InnerText = "Zelanzy, Roger";
book.AppendChild(title);
book.AppendChild(author);
root.AppendChild(book);
string xmlOutput = doc.OuterXml;
The same code but using an XMLWriter to a memory stream.

XmlWriterSettings wSettings = new XmlWriterSettings();
wSettings.Indent = true;
MemoryStream ms = new MemoryStream();
XmlWriter xw = XmlWriter.Create(ms, wSettings);// Write Declaration
xw.WriteStartDocument();
// Write the root node
xw.WriteStartElement("Library");
// Write the books and the book elements
xw.WriteStartElement("Book");
xw.WriteStartAttribute("BookType");
xw.WriteString("Hardback");
xw.WriteEndAttribute();
xw.WriteStartElement("Title");
xw.WriteString("Door Number Three");
xw.WriteEndElement();
xw.WriteStartElement("Author");
xw.WriteString("O'Leary, Patrick");
xw.WriteEndElement();
xw.WriteEndElement();
// Write another book
xw.WriteStartElement("Book");
xw.WriteStartAttribute("BookType");
xw.WriteString("Paperback");
xw.WriteEndAttribute();
xw.WriteStartElement("Title");
xw.WriteString("Lord of Light");
xw.WriteEndElement();
xw.WriteStartElement("Author");
xw.WriteString("Zelanzy, Roger");
xw.WriteEndElement();
xw.WriteEndElement();
// Close the document
xw.WriteEndDocument();
// Flush the write
xw.Flush();
Byte[] buffer = new Byte[ms.Length];
buffer = ms.ToArray();
string xmlOutput = System.Text.Encoding.UTF8.GetString(buffer);

If you don't want (or can't) to use LINQ to XML, neither to duplicate your Order class to include XML serialization, and thinks XmlWriter is too much verbose, you can go with plain classical XmlDocument class:

// consider Order class that data structure you receive from your ERP system
List<Order> orders = YourERP.GetOrders();
XmlDocument xml = new XmlDocument();
xml.AppendChild(xml.CreateElement("Orders"));
foreach (Order order in orders)
{
    XmlElement item = xml.CreateElement("Order");
    item.SetAttribute("OrderNumber", order.OrderNumber);
    item.AppendChild(xml.CreateElement("ItemNumber")).Value = order.ItemNumber;
    item.AppendChild(xml.CreateElement("QTY"       )).Value = order.Quantity;
    item.AppendChild(xml.CreateElement("WareHouse" )).Value = order.WareHouse;
    xml.DocumentElement.AppendChild(item);
}

There are a lot of good suggestions in this thread, but one that hasn't been mentioned: Defining an ADO DataSet and serializing/deserializing using the ReadXml and WriteXml methods. This can be a very simple and attractive solution. Your XML isn't in quite the right format, but it's close.

I found it largely depends how complex your original data is.

If your data is nicely organized in objects and it is sufficient to dump it in XML, Linq is very verbose and powerful. But as soon as there are object inter-dependencies, I don't think you want to go with the Linq one-liner, as this is real pain to debug and/or extend.

For those cases, I'd prefer to go with XmlDocument, create a help method to facilitate adding attributes to an element (see below), and use Linq in foreach loops around the XML creation blocks.

private void XAttr(ref XmlNode xn, string nodeName, string nodeValue)
{
    XmlAttribute result = xn.OwnerDocument.CreateAttribute(nodeName); 
    result.InnerText = nodeValue;
    xn.Attributes.Append(result);
}

You just right click on your code window , select InsertSnippet follow this Link