C#取得各種類型文件信息.

痛定思痛。 2022-08-25 05:23 151阅读 0赞

1.取文件基本信息  
首先需要根据文件名来创建FileInfo对象

using  System.IO;  
FileInfo fi  =  new  FileInfo( yourFileName );

那么以后就可以通过此对象来访问文件一些属性，例如文件大小，创建时间，最后访问时间，最后写入时间等等，还可以通过访问对象的Attributes属性，来获得当前文件是只读、隐藏之类属性.

2.取文件Version  
并不是所有的文件都有Version信息，因此在使用FileVersionInfo的时候需要注意的是，最好先判断一下文件的扩展名。不过一个FileVersionInfo类对象不能通过构造函数来创建，需要调用类的静态方法来获得，例如：

using  System.Diagnostics;  
FileVersionInfo fvi  =  FileVersionInfo.GetVersionInfo( yourFileName );

通过此对象，可以获得文件的产品名称，公司名，版本号，语言版本，版权等等

3.取文件擴展信息,如标题，作者等等

.net框架中並沒有提供相關的類來支持這個操作,但我們可以利用Com組件"Microsoft Shell Controls and Automation"取得文件的擴展信息,这个COM是由系统“Shell32.dll”提供.實現步驟如下:  
\--1.首先寫一個幫助類

//  Helper Class from holding the detailed File Informations of the System   
  public  class  DetailedFileInfo  
\{  
 int  iID  =  0 ;  
 string  sValue  =  "" ;  
 public  int  ID  
\{  
 get  \{  return  iID; \}  
 set   
\{  
iID  =  value;  
\}  
\}  
 public  string  Value  
\{  
 get  \{  return  sValue; \}  
 set  \{ sValue  =  value; \}  
\}  
 public  DetailedFileInfo( int  ID,  string  Value)  
\{  
iID  =  ID;  
sValue  =  Value;  
\}  
  
\}

\--2.編寫取文件信息的類

using  System.IO;  
 using  System.Collections;  
 using  Shell32;  
  
 ///  <summary>   
 ///  Returns the detailed Information of a given file.  
 ///  </summary>   
  public  class  CFileInfo  
\{  
 private  string  sFileName  =  "" ,  
sFullFileName  =  "" ,  
sFileExtension  =  "" ,  
sFilePath  =  "" ,  
sFileComment  =  "" ,  
sFileAuthor  =  "" ,  
sFileTitle  =  "" ,  
sFileSubject  =  "" ,  
sFileCategory  =  "" ,  
sFileType  =  "" ;  
  
 private  long  lFileLength  =  0 ,  
lFileVersion  =  0 ;  
  
 private  DateTime dCreationDate,  
dModificationDate;  
  
 public  CFileInfo( string  sFPath)  
\{  
 //  check if the given File exists   
   
 if  (File.Exists(sFPath))  
\{  
ArrayList aDetailedInfo  =  new  ArrayList();  
FileInfo oFInfo  =  new  FileInfo(sFPath);  
sFileName  =  oFInfo.Name;  
sFullFileName  =  oFInfo.FullName;  
sFileExtension  =  oFInfo.Extension;  
lFileLength  =  oFInfo.Length;  
sFilePath  =  oFInfo.Directory.ToString();  
dCreationDate  =  oFInfo.CreationTime;  
dModificationDate  =  oFInfo.LastWriteTime;  
  
 \#region  "read File Details"   
aDetailedInfo  =  GetDetailedFileInfo(sFPath);  
 foreach  (DetailedFileInfo oDFI  in  aDetailedInfo)  
\{  
 switch  (oDFI.ID)  
\{  
 case  2 :  
sFileType  =  oDFI.Value;  
 break ;  
  
 case  9 :  
sFileAuthor  =  oDFI.Value;  
 break ;  
  
 case  10 :  
sFileTitle  =  oDFI.Value;  
 break ;  
  
 case  11 :  
sFileSubject  =  oDFI.Value;  
 break ;  
  
 case  12 :  
sFileCategory  =  oDFI.Value;  
 break ;  
  
 case  14 :  
sFileComment  =  oDFI.Value;  
 break ;  
  
 default :  
  
 break ;  
\}  
\}  
  
 \#endregion   
  
\}  
 else   
\{  
 throw  new  Exception( " The given File does not exist " );  
\}  
  
\}  
  
 \#region  "Properties"   
 // 文件名   
  public  string  FileName  
\{  
 get  \{  return  sFileName; \}  
 set  \{ sFileName  =  value; \}  
\}  
 // 路徑   
  public  string  FilePath  
\{  
 get  \{  return  sFilePath; \}  
 set  \{ sFilePath  =  value; \}  
\}  
 // 完整名稱   
  public  string  FullFileName  
\{  
 get  \{  return  sFullFileName; \}  
 set  \{ sFullFileName  =  value; \}  
\}  
 // 擴展名   
  public  string  FileExtension  
\{  
 get  \{  return  sFileExtension; \}  
 set  \{ sFileExtension  =  value; \}  
\}  
 // 大小   
  public  long  FileSize  
\{  
 get  \{  return  lFileLength; \}  
 set  \{ lFileLength  =  value; \}  
\}  
 // 版本號   
  public  long  FileVersion  
\{  
 get  \{  return  lFileVersion; \}  
 set  \{ lFileVersion  =  value; \}  
\}  
 // 建立日期   
  public  DateTime FileCreationDate  
\{  
 get  \{  return  dCreationDate; \}  
 set  \{ dCreationDate  =  value; \}  
\}  
 // 修改日期   
  public  DateTime FileModificationDate  
\{  
 get  \{  return  dModificationDate; \}  
 set  \{ dModificationDate  =  value; \}  
\}  
 // 類型   
  public  string  FileType  
\{  
 get  \{  return  sFileType; \}  
\}  
 // 標題   
  public  string  FileTitle  
\{  
 get  \{  return  sFileTitle; \}  
\}  
 // 主旨   
  public  string  FileSubject  
\{  
 get  \{  return  sFileSubject; \}  
\}  
 // 作者   
  public  string  FileAuthor  
\{  
 get  \{  return  sFileAuthor; \}  
\}  
 // 類別   
  public  string  FileCategory  
\{  
 get  \{  return  sFileCategory; \}  
\}  
 // 注釋   
  public  string  FileComment  
\{  
 get  \{  return  sFileComment; \}  
\}  
 \#endregion   
  
 \#region  "Methods"   
  
 private  ArrayList GetDetailedFileInfo( string  sFile)  
\{  
ArrayList aReturn  =  new  ArrayList();  
 if  (sFile.Length  >  0 )  
\{  
 try   
\{  
 //  Creating a ShellClass Object from the Shell32   
  ShellClass sh  =  new  ShellClass();  
 //  Creating a Folder Object from Folder that inculdes the File   
  Folder dir  =  sh.NameSpace(Path.GetDirectoryName(sFile));  
 //  Creating a new FolderItem from Folder that includes the File   
  FolderItem item  =  dir.ParseName(Path.GetFileName(sFile));  
 //  loop throw the Folder Items   
  for  ( int  i  =  0 ; i  <  30 ; i \++ )  
\{  
 //  read the current detail Info from the FolderItem Object  
 // (Retrieves details about an item in a folder. For example, its size, type, or the time of its last modification.)  
 //  some examples:  
 //  0 Retrieves the name of the item.  
 //  1 Retrieves the size of the item.  
 //  2 Retrieves the type of the item.  
 //  3 Retrieves the date and time that the item was last modified.  
 //  4 Retrieves the attributes of the item.  
 //  \-1 Retrieves the info tip information for the item.    
   
 string  det  =  dir.GetDetailsOf(item, i);  
  
 //  Create a helper Object for holding the current Information  
 //  an put it into a ArrayList   
  DetailedFileInfo oFileInfo  =  new  DetailedFileInfo(i, det);  
aReturn.Add(oFileInfo);  
\}  
\}  
 catch  (Exception)  
\{  
  
\}  
  
\}  
  
 return  aReturn;  
  
\}  
  
 \#endregion   
\}

4.一個具體的問題,如何判斷文件真正的格式.

簡單的通過文件後綴名,我們是得不到文件真正的格式的.文件真正的格式是通過文件頭來做判斷的.那麼我們該如何取得文件真正的格式呢?如果是圖片,那麼好辦,.通過.net自帶的函數就可以輕松判斷圖片真正的格式:

private  bool  IsJpegImageFormat( string  filesName)  
\{  
 if  ( ! File.Exists(filesName))  return  false ;  
 bool  isTrue  =  false ;  
 using  (System.Drawing.Image img  =  System.Drawing.Image.FromFile(filesName))  
\{  
 if  (img.RawFormat.Equals(System.Drawing.Imaging.ImageFormat.Jpeg)) isTrue  =  true ;  
\}  
 return  isTrue;  
\}

對於非圖片的文件,.net框架好像並沒有提供相關的支持,由於文件類型有很多,而且很多文件的文件頭格式並沒有公開,所以這其實是個相當複雜的問題.目前我還沒有找到很好的方法.以下幾個鏈接或許對認識這個問題有所幫助:

首先看看文件的類型吧:  
[http://www.utoronto.ca/webdocs/HTMLdocs/Book/Book-3ed/appb/mimetype.html][http_www.utoronto.ca_webdocs_HTMLdocs_Book_Book-3ed_appb_mimetype.html]  
再來看看不同類型的文件頭:  
[http://blog.csdn.net/georgejin/archive/2007/08/11/1737927.aspx][http_blog.csdn.net_georgejin_archive_2007_08_11_1737927.aspx]  
最後看一下編程實現的2個例子:  
[http://www.cnblogs.com/jhtchina/archive/2007/02/12/93412.html][http_www.cnblogs.com_jhtchina_archive_2007_02_12_93412.html]  
[http://www.tcdongli.com/article.asp?id=14][http_www.tcdongli.com_article.asp_id_14]

參考文獻: [http://blog.csdn.net/knight94/archive/2006/05/07/711327.aspx][http_blog.csdn.net_knight94_archive_2006_05_07_711327.aspx]

[http_www.utoronto.ca_webdocs_HTMLdocs_Book_Book-3ed_appb_mimetype.html]: http://www.utoronto.ca/webdocs/HTMLdocs/Book/Book-3ed/appb/mimetype.html
[http_blog.csdn.net_georgejin_archive_2007_08_11_1737927.aspx]: http://blog.csdn.net/georgejin/archive/2007/08/11/1737927.aspx
[http_www.cnblogs.com_jhtchina_archive_2007_02_12_93412.html]: http://www.cnblogs.com/jhtchina/archive/2007/02/12/93412.html
[http_www.tcdongli.com_article.asp_id_14]: http://www.tcdongli.com/article.asp?id=14
[http_blog.csdn.net_knight94_archive_2006_05_07_711327.aspx]: http://blog.csdn.net/knight94/archive/2006/05/07/711327.aspx