一些 HTML内容比较/文本差异比较开源代码

1. DiffPlex - a .NET Diff Generator
http://diffplex.codeplex.com/

简介：

具体使用可以参考http://diffplex.codeplex.com/wikipage?title=library&referringTitle=Home

IDiffer是差异比较的核心类，提供了两个文本的低精度的大致比较

ISidebySideDiff：提供了高精度的比较以及可以用两栏对比显示差异

接口

Silverlight

Website

2.diffengine

简介：

功能强大，

缺点：文本每行不能超过1024个字符

DifferenceEngine.DiffList_TextFile sourceFile  null;
DifferenceEngine.DiffList_TextFile destinationFile = null;

sourceFile = new DifferenceEngine.DiffList_TextFile("1.txt");
destinationFile = new DifferenceEngine.DiffList_TextFile("2.txt");

DifferenceEngine.DiffEngine engine = new DifferenceEngine.DiffEngine();
engine.ProcessDiff(sourceFile,destinationFile, DifferenceEngine.DiffEngineLevel.FastImperfect);
ArrayList diffLines = engine.DiffReport();
foreach (DifferenceEngine.DiffResultSpan span in diffLines)
{
   switch (span.Status)
    {
case ifferenceEngine.DiffResultSpanStatus.NoChange:
    //没改变
      break;
case DifferenceEngine.DiffResultSpanStatus.AddDestination:
//新增的
     break;
case DifferenceEngine.DiffResultSpanStatus.DeleteSource:
//已删除的
     break;
case DifferenceEngine.DiffResultSpanStatus.Replace:
//修改的
                break;
default:
//  默认
                      break;

                }

            }

获取新增内容示例：

string str = ((DifferenceEngine.TextLine)(destinationFile.GetByIndex(span.DestIndex))).Line;

http://www.codeproject.com/KB/recipes/diffengine.aspx