对XAML进行编辑的辅助类（XamlHelper）

// XamlHelper.cs
// --------------------------------------------
// 对XAML进行编辑操作的辅助类:
// 对选中的XAML进行操作; 对XAML代码进行对齐整理; 对XAML标记进行着色显示等
// --------------------------------------------
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Collections;
using System.Windows;
using System.IO;
using System.Xml;
using System.Windows.Markup;

namespace BrawDraw.Com.Xaml.Utility
{

    /// <summary>
    /// Provides help functions for processing XAML.
    /// </summary>
    public class XamlHelper
    {
        /// <summary>
        /// Get XAML from TextRange.Xml property
        /// </summary>
        /// <param name="range">TextRange</param>
        /// <returns>return a string serialized from the TextRange</returns>
        public static string GetTextRangeXaml(TextRange range)
        {
            MemoryStream mstream;

            if (range == null)
            {
                throw new ArgumentNullException("range");
            }

            mstream = new MemoryStream();
            range.Save(mstream, DataFormats.Xaml);

            //must move the stream pointer to the beginning since range.save() will move it to the end.
            mstream.Seek(0, SeekOrigin.Begin);

            //Create a stream reader to read the xaml.
            StreamReader stringReader = new StreamReader(mstream);

            return stringReader.ReadToEnd();
        }

        /// <summary>
        /// Set XML to TextRange.Xml property.
        /// </summary>
        /// <param name="range">TextRange</param>
        /// <param name="xaml">XAML to be set</param>
        public static void SetTextRangeXaml(TextRange range, string xaml)
        {
            MemoryStream mstream;
            if (null == xaml)
            {
                throw new ArgumentNullException("xaml");
            }
            if (range == null)
            {
                throw new ArgumentNullException("range");
            }

            mstream = new MemoryStream();
            StreamWriter sWriter = new StreamWriter(mstream);

            mstream.Seek(0, SeekOrigin.Begin); //this line may not be needed.
            sWriter.Write(xaml);
            sWriter.Flush();

            //move the stream pointer to the beginning.
            mstream.Seek(0, SeekOrigin.Begin);

            range.Load(mstream, DataFormats.Xaml);
        }

        /// <summary>
        /// Parse a string to WPF object.
        /// </summary>
        /// <param name="str">string to be parsed</param>
        /// <returns>return an object</returns>
        public static object ParseXaml(string str)
        {
            MemoryStream ms = new MemoryStream(str.Length);
            StreamWriter sw = new StreamWriter(ms);
            sw.Write(str);
            sw.Flush();

            ms.Seek(0, SeekOrigin.Begin);

            ParserContext pc = new ParserContext();

            pc.BaseUri = new Uri(System.Environment.CurrentDirectory + "/");

            return XamlReader.Load(ms, pc);
        }

        public static string IndentXaml(string xaml)
        {
            //open the string as an XML node
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.LoadXml(xaml);
            XmlNodeReader nodeReader = new XmlNodeReader(xmlDoc);

            //write it back onto a stringWriter
            System.IO.StringWriter stringWriter = new System.IO.StringWriter();
            System.Xml.XmlTextWriter xmlWriter = new System.Xml.XmlTextWriter(stringWriter);
            xmlWriter.Formatting = System.Xml.Formatting.Indented;
            xmlWriter.Indentation = 4;
            xmlWriter.IndentChar = ' ';
            xmlWriter.WriteNode(nodeReader, false);

            string result = stringWriter.ToString();
            xmlWriter.Close();

            return result;
        }

        public static string RemoveIndentation(string xaml)
        {
            if (xaml.Contains("/r/n    "))
            {
                return RemoveIndentation(xaml.Replace("/r/n    ", "/r/n"));
            }
            else
            {
                return xaml.Replace("/r/n", "");
            }
        }

        public static string ColoringXaml(string xaml)
        {
            string[] strs;
            string value = "";
            string s1, s2;
            s1 = "<Section xml:space=/"preserve/" xmlns=/"http://schemas.microsoft.com/winfx/2006/xaml/presentation/"><Paragraph>";
            s2 = "</Paragraph></Section>";

            strs = xaml.Split(new char[] { '<' });
            for (int i = 1; i < strs.Length; i++)
            {
                value += ProcessEachTag(strs[i]);
            }
            return s1 + value + s2;
        }

        static string ProcessEachTag(string str)
        {
            string front = "<Run Foreground=/"Blue/">&lt;</Run>";
            string end = "<Run Foreground=/"Blue/">&gt;</Run>";
            string frontWithSlash = "<Run Foreground=/"Blue/">&lt;/</Run>";
            string endWithSlash = "<Run Foreground=/"Blue/"> /&gt;</Run>";//a space is added.
            string tagNameStart = "<Run FontWeight=/"Bold/">";
            string propertynameStart = "<Run Foreground=/"Red/">";
            string propertyValueStart = "/"<Run Foreground=/"Blue/">";
            string endRun = "</Run>";
            string returnValue;
            string[] strs;
            int i = 0;

            if (str.StartsWith("/"))
            {   //if the tag is an end tag, remove the "/"
                returnValue = frontWithSlash;
                str = str.Substring(1).TrimStart();
            }
            else
            {
                returnValue = front;
            }
            strs = str.Split(new char[] { '>' });
            str = strs[0];
            i = (str.EndsWith("/")) ? 1 : 0;

            str = str.Substring(0, str.Length - i).Trim();

            if (str.Contains("="))//the tag has a property
            {
                //set tagName
                returnValue += tagNameStart + str.Substring(0, str.IndexOf(" ")) + endRun + " ";
                str = str.Substring(str.IndexOf(" ")).Trim();
            }
            else //no property
            {
                returnValue += tagNameStart + str.Trim() + endRun + " ";
                //nothing left to parse
                str = "";
            }

            //Take care of properties:
            while (str.Length > 0)
            {
                returnValue += propertynameStart + str.Substring(0, str.IndexOf("=")) + endRun + "=";
                str = str.Substring(str.IndexOf("/"") + 1).Trim();
                returnValue += propertyValueStart + str.Substring(0, str.IndexOf("/"")) + endRun + "/" ";
                str = str.Substring(str.IndexOf("/"") + 1).Trim();
            }

            if (returnValue.EndsWith(" "))
            {
                returnValue = returnValue.Substring(0, returnValue.Length - 1);
            }

            returnValue += (i == 1) ? endWithSlash : end;

            //Add the content after the ">"
            returnValue += strs[1];

            return returnValue;
        }
    }
}