亂馬客

前言

依目錄、檔名尋找符合的檔案清單，最常用就是使用For Each的方式，但是也可以使用LINQ來找哦!

實作

範例說明

• Search Dir中有部門的目錄。
• 部門:Dept_1~Dept_5。
• 每個部門目錄中有2009.txt & 2010.txt
• 可在要找的部門欄位中輸入要找的目錄名稱，多個以逗號隔開(空字串表示不篩選，全部出來)。
• 可在要找的檔案欄位中輸入要找的檔案名稱，多個以逗號隔開(空字串表示不篩選，全部出來)。

1.使用For Each

			   1:  /// <summary>

			   2:  /// 使用ForEach來找檔案

			   3:  /// </summary>

			   4:  /// <param name="sender"></param>

			   5:  /// <param name="e"></param>

			   6:  /// <remarks>

			   7:  /// 當查詢清單為空表示全部查出來

			   8:  /// </remarks>

			   9:  private void btnSearchForEach_Click(object sender, EventArgs e)

			  10:  {

			  11:      string startFolder = txtSearchDir.Text;

			  12:      string[] aryFolderName = Directory.GetDirectories(startFolder);

			  13:      char[] splitChar = new char[] { ',' };

			  14:      //要找的部門清單

			  15:      string[] searchDeptList = txtDeptList.Text.Trim().Split(splitChar);

			  16:      //要找的檔案清單

			  17:      string[] searchFileList = txtFileList.Text.Trim().Split(splitChar);

			  18:      txtSearchResult.Text = string.Empty;

			  19:      foreach (string strFolder in aryFolderName)

			  20:      {

			  21:          if (txtDeptList.Text.Trim().Length > 0)

			  22:          {

			  23:              //有設定部門篩選

			  24:              foreach (string strFilterFolder in searchDeptList)

			  25:              {

			  26:                  if (strFolder == Path.Combine(startFolder, strFilterFolder))

			  27:                  {

			  28:                      //有符合的Folder

			  29:                      string[] aryFileList = Directory.GetFiles(strFolder);

			  30:                      foreach (string strFile in aryFileList)

			  31:                      {

			  32:                          if (txtFileList.Text.Trim().Length > 0)

			  33:                          {

			  34:                              //有設定檔案篩選

			  35:                              foreach (string strFilterFile in searchFileList)

			  36:                              {

			  37:                                  if (strFilterFile.ToUpper() == Path.GetFileName(strFile).ToUpper())

			  38:                                  {

			  39:                                      txtSearchResult.Text += strFile + Environment.NewLine;

			  40:                                  }

			  41:                              }

			  42:                          }

			  43:                          else

			  44:                          {

			  45:                              //沒有設定檔案篩選

			  46:                              txtSearchResult.Text += strFile + Environment.NewLine;

			  47:                          }

			  48:                          

			  49:                      }

			  50:                  }

			  51:              }

			  52:          }

			  53:          else

			  54:          {

			  55:              //沒有設定部門篩選

			  56:              string[] aryFileList = Directory.GetFiles(strFolder);

			  57:              foreach (string strFile in aryFileList)

			  58:              {

			  59:                  if (txtFileList.Text.Trim().Length > 0)

			  60:                  {

			  61:                      //有設定檔案篩選

			  62:                      foreach (string strFilterFile in searchFileList)

			  63:                      {

			  64:                          if (strFilterFile.ToUpper() == Path.GetFileName(strFile).ToUpper())

			  65:                          {

			  66:                              txtSearchResult.Text += strFile + Environment.NewLine;

			  67:                          }

			  68:                      }

			  69:                  }

			  70:                  else

			  71:                  {

			  72:                      //沒有設定檔案篩選

			  73:                      txtSearchResult.Text += strFile + Environment.NewLine;

			  74:                  }

			  75:   

			  76:              }

			  77:          }

			  78:          

			  79:      }

			  80:   

			  81:  }

2.使用LINQ

			   1:  /// <summary>

			   2:  /// 使用LINQ來找Files

			   3:  /// </summary>

			   4:  /// <param name="sender"></param>

			   5:  /// <param name="e"></param>

			   6:  /// <remarks>

			   7:  /// 當查詢清單為空表示全部查出來

			   8:  /// </remarks>

			   9:  private void btnSearch_Click(object sender, EventArgs e)

			  10:  {

			  11:      string startFolder = txtSearchDir.Text;

			  12:      // Take a snapshot of the file system.

			  13:      System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(startFolder);

			  14:   

			  15:      // This method assumes that the application has discovery permissions

			  16:      // for all folders under the specified path.

			  17:      IEnumerable<System.IO.FileInfo> fileList = dir.GetFiles("*.*", System.IO.SearchOption.AllDirectories);

			  18:   

			  19:      char[] splitChar = new char[]{','};

			  20:   

			  21:      //要找的部門清單

			  22:      string[] searchDeptList = txtDeptList.Text.Trim().Split(splitChar);

			  23:      //要找的檔案清單

			  24:      string[] searchFileList = txtFileList.Text.Trim().Split(splitChar);

			  25:   

			  26:      //Create the query 如果清單為空，就找出全部的資料

			  27:      IEnumerable<System.IO.FileInfo> fileQuery =

			  28:          from file in fileList

			  29:          from d in searchDeptList

			  30:          where file.DirectoryName == Path.Combine(startFolder, d) || d == string.Empty 

			  31:          from f in searchFileList

			  32:          where file.Name.ToUpper() == f.ToUpper() || f == string.Empty

			  33:          orderby file.DirectoryName

			  34:          select file;

			  35:           

			  36:   

			  37:      txtSearchResult.Text = string.Empty;

			  38:      //Execute the query. This might write out a lot of files!

			  39:      foreach (System.IO.FileInfo fi in fileQuery)

			  40:      {

			  41:          txtSearchResult.Text +=   fi.FullName   + Environment.NewLine;

			  42:      }

			  43:  }

結論

使用LINQ來找似乎比較直覺一點，而在篩選資料時，把要篩選的Folder Name 及 File Name當成另外一個資料來源，跟全部的Files一起Join，同時加上當篩選的資料為空值時，就不篩選(全部出來)，所以就不能直接使用join，而要使用form where的方式!  如下，

 IEnumerable fileQuery =
from file in fileList
from d in searchDeptList
where file.DirectoryName == Path.Combine(startFolder, d) || d == string.Empty
from f in searchFileList
where file.Name.ToUpper() == f.ToUpper() || f == string.Empty
orderby file.DirectoryName
select file;

參考資訊

How to: Query for Files with a Specified Attribute or Name

範例

LinQFiles.rar

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