上一篇文章实现了可视化显示不同路径下相同文件夹内的文件和子文件夹差异，文件少时已经够用，但当有成百上千个子文件夹时，人工逐个查看文件夹差异就比较困难，因此本文实现循环查找文件夹内容差异并导出为本地Excel文件的功能。
本文使用队列保存要差异对比的文件夹及子文件夹路径，没有使用递归，代码逻辑看着稍微有点别扭，主要代码如下：
List<DirectoryCompareRecord> results= new List<DirectoryCompareRecord>();Queue<string> subDirs= new Queue<string>();string leftDir=txtLeftDir.Text.TrimEnd('\\');
string rightDir=txtRightDir.Text.TrimEnd('\\');
string curLeftDir = string.Empty;
string curRightDir = string.Empty;List<string> subLeftDirs = new List<string>();
List<string> subRightDirs = new List<string>();
List<string> subLeftFiles = new List<string>();
List<string> subRightFiles = new List<string>();string tmpFileName = string.Empty;
string tmpDirName = string.Empty;
string tmp = string.Empty;FileInfo leftFile = null;
FileInfo rightFile = null;do
{ curLeftDir = Path.Combine(leftDir, tmp);curRightDir = Path.Combine(rightDir, tmp);subLeftDirs.Clear();subRightDirs.Clear();subLeftFiles.Clear();subRightFiles.Clear();subLeftFiles.AddRange(Directory.GetFiles(curLeftDir));subRightFiles.AddRange(Directory.GetFiles(curRightDir));subLeftFiles.Sort();subRightFiles.Sort();foreach (string file in subLeftFiles){tmpFileName = Path.GetFileName(file);tmpDirName = Path.Combine(curRightDir, tmpFileName);if (!subRightFiles.Contains(tmpDirName)){DirectoryCompareRecord record = new DirectoryCompareRecord();record.ObjectType = "文件";record.ResultType = "文件缺失";record.LeftDirectory = curLeftDir;record.LeftFile = tmpFileName;results.Add(record);}else{leftFile=new FileInfo(file);rightFile=new FileInfo(tmpDirName);if (leftFile.LastWriteTime != rightFile.LastWriteTime){DirectoryCompareRecord record = new DirectoryCompareRecord();record.ObjectType = "文件";record.ResultType = "文件有差异";record.LeftDirectory = curLeftDir;record.LeftFile = tmpFileName;record.LeftFileLastModifyDate = leftFile.LastWriteTime.ToString();record.RightDirectory = curRightDir;record.RightFile = tmpFileName;record.RightFileLastModifyDate = rightFile.LastWriteTime.ToString();results.Add(record);}else{subRightFiles.Remove(tmpDirName);} }}foreach (string file in subRightFiles){tmpFileName = Path.GetFileName(file);tmpDirName = Path.Combine(curLeftDir, tmpFileName);if (!subLeftFiles.Contains(tmpDirName)){DirectoryCompareRecord record = new DirectoryCompareRecord();record.ObjectType = "文件";record.ResultType = "文件缺失";record.RightDirectory = curRightDir;record.RightFile = tmpFileName;results.Add(record);}}subLeftDirs.AddRange(Directory.GetDirectories(curLeftDir));subRightDirs.AddRange(Directory.GetDirectories(curRightDir));subLeftDirs.Sort();subRightDirs.Sort();foreach (string dir in subLeftDirs){tmpFileName = Path.GetFileName(dir);tmpDirName = Path.Combine(curRightDir, tmpFileName);if (!subRightDirs.Contains(tmpDirName)){DirectoryCompareRecord record = new DirectoryCompareRecord();record.ObjectType = "文件夹";record.ResultType = "文件夹缺失";record.LeftDirectory = curLeftDir;record.LeftFile = tmpFileName;results.Add(record);}else{subDirs.Enqueue(dir.Substring(leftDir.Length+1));subRightFiles.Remove(tmpDirName); }}foreach (string file in subRightDirs){tmpFileName = Path.GetFileName(file);tmpDirName = Path.Combine(curLeftDir, tmpFileName);if (!subLeftDirs.Contains(tmpDirName)){DirectoryCompareRecord record = new DirectoryCompareRecord();record.ObjectType = "文件夹";record.ResultType = "文件夹缺失";record.RightDirectory = curRightDir;record.RightFile = tmpFileName;results.Add(record);}}if(subDirs.Count>0){tmp=subDirs.Dequeue();}} while (subDirs.Count >0);
对比结果导出Excel文件采用Sylvan.Data.Excel库，代码实现也比较简单，如下所示：
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "XLSX|*.xlsx";
if (saveFileDialog.ShowDialog() != DialogResult.OK)
{return;
}DbDataReader reader = ObjectDataReader.Create(results);
using (var w = ExcelDataWriter.Create(saveFileDialog.FileName))
{w.Write(reader);
}
最后是程序运行效果及导出文件的效果，代码地址：https://github.com/guochao2299/DirCompare
参考文献：
[1]https://blog.csdn.net/sd7o95o/article/details/142976888
[2]https://github.com/MarkPflug/Sylvan.Data.Excel
