C# - Method help

Question

Hi there I am just kind of stuck right now and looking over FileSystemWatcher Class but i need help. I have to create a class that will monitor and delete all files older thatXnumber of days. I have to create 2 methods DeleteFilesOlderThan() FilesOlderThan() and similarly have DeleteFilesOlderThan() method call FilesOlderThan() All i have done is this.... [CODE] // Deletes the files older the days hours and minutes specified public int DeleteFilesOlderThan( int Days int Hrs int Mins){} // Reurns filenames having last modified time older than specified period public string [] FilesOlderThan( int Days int Hrs int Mins){} [/CODE] Thanks for your help!!!

saurabh · Answer

Can we implement this using a web service for deleting files .Also can we add extra logic into this  if suppose we have copies of files and we want to delete files all copies files which are older 30 days but keeping three copies intact...and if the copy files are 60 days old then delete all the copies of the files...Please help!!

Alan · Answer

True but it also gives you a random extension as well so it's no use for testing the extension filter in your application.

Shani · Answer

The following c# function can also generate a unique random file name =] Path.GetRandomFileName();

Alan · Answer

Well it would certainly be possible to generate a random number to append to the file name but I can't see the point as all you need is a unique number which the code you've already written gives you. The random number generator class in .NET cannot guarantee uniqueness in any case. The System.Exception.Message property is virtual and so when an error occurs the message will relate to the actual exception not the generic one. I'm not aware of any way to get a fuller message than this that would be useful for your application. Incidentally you won't get any .dat files with that code because any number that divides by 9 will already have been filtered out by the 'divides by 3' code. You need to use prime numners i.e. 11 for .dat and 13 for .jpg.

Shani · Answer

yeah I get what you mean. Using System.Exception you can possibly catch all the exceptions. Other than System.Exceptions I want to catch all the other exceptions with different error message what can i do for that. The following code is generating files perfectly But when i change the date on my laptop to get files with different modified times. It just overrides all the files with the recent date. private void GenerateTestFiles_Click(object sender EventArgs e) { StreamWriter outStream = null; string message = null; for (int i = 0; i { string filename = output; filename += i.ToString(); if (i % 3 == 0) {//multiple of three filename += .txt; } else if (i % 5 == 0) {//multiple of 5 filename += .log; } else if (i % 7 == 0) {// multiple of 7 filename += .exe; } else if (i % 9 == 0) {// miltiple of 9 filename += .dat; } else if (i % 11 == 0) {// multiple of 11 filename += .jpq; } else { filename += .bmp; } FolderWatcher fw = new FolderWatcher(); filename = fw.FolderPath + C:\CsharpTempFolder\ + filename; try { outStream = new StreamWriter(filename); outStream.WriteLine(Hello World); outStream.Close(); } catch (Exception Ex) { message = Unable to create  + filename + 
; message += String.Format(Reason: {0} Ex.Message); MessageBox.Show(message); } } } 1. Can i generate files with random numbers. Like in the loop i takes random values using System.Random class. Or add datetime object. what is the most simpliest way of doing it. 2. I am just showing the error message in the catch statements for this and deleteFilesOlderThan(). I want to show the entire message not just the message part because i might miss out some essential info.

Alan · Answer

Well unless you're trying to watch a folder on removable media which somebody's forgotten to insert into the machine there will be no remedial action you can take if a file cannot be deleted for some reason. So all you can do is to simply write out the error message to say why a file couldn't be deleted. In these circumstances you might as well catch all exceptions generically (using System.Exception) as you are doing already. There's no point in trying to catch specific exceptions as the code to display the message would be just the same.

Shani · Answer

Yup Thanks:) This worked. FolderWatcher fw = new FolderWatcher(); filename = fw.FolderPath + C:\CsharpTempFolder\ + filename; So Since I moved away from console object and moved towards exception objects. How am I going to handle all the possible exceptions I can get using my code. e.g FileNotFoundExceptionDirectoryNotFoundExceptionFileLoadException. Is this the proper way? public int DeleteFilesOlderThan(int Days int Hrs int Mins string filter) { DateTime dt = GetRelativeDateTime(Days Hrs Mins); ArrayList oldFilePaths = FilesOlderThan(dt filter); int count = 0; string message = null; foreach (string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch (FileNotFoundException e) { } catch (DirectoryNotFoundException e) { } catch (Exception e) { message = Unable to delete  + filePath + 
; message += String.Format(Reason: {0} e.Message); MessageBox.Show(message); // Error..Property or indexer 'System.Exception.Message' cannot be assigned to--it is read only //e.Message = Unable to delete  + filePath + e.ToString(); //Console.WriteLine(Unable to delete  + filePath); //Console.WriteLine(Reason: {0}  e); } //message = (Files successfully deleted); //MessageBox.Show(message); //message = String.Format({0} ex {1} files successfully deleted count oldFilePaths.Count); //MessageBox.Show(message); //return count; } return count; }

Alan · Answer

Well you've got your temporary folder stored in fw.FolderPath. So immediately before the 'try' statement you need this line: filename = fw.FolderPath + \ + filename;

Shani · Answer

This code i tried works fine to create dummy files. How do i point it to my specified path private void button1_Click(object sender EventArgs e) { StreamWriter outStream = null; string message = null; for (int i = 0; i { string filename = output; filename += i.ToString(); if (i % 3 == 0) {//multiple of three filename += .txt; } else if (i % 5 == 0) {//multiple of 5 filename += .log; } else if ( i % 7 == 0) { filename += .exe; } else if (i % 9 == 0) { filename += .dat; } else if (i % 11 == 0) { filename += .jpq; } else { filename += .bmp; } try { outStream = new StreamWriter(filename); outStream.WriteLine(Hello World); //Thread.Sleep(60000); outStream.Close(); } catch (IOException e1) { message = Unable to create  + filename + 
; message += String.Format(Reason: {0} e1.Message); MessageBox.Show(message); } }

Shani · Answer

Yup:) That works fine...Thank you

Alan · Answer

I think I've found the problem which is this line in the FilesOlderThan() method: older.Add(file.Name); //add it to the list It should be: older.Add(file. Full Name); //add it to the list What was happening is that the ArrayList only contained the simple file names not the full paths. File.Delete() was assuming that they were in the current working folder (not the watched folder) and was attempting to delete them from there. Not sure how that snook in there - I think we've just changed the code too many times.

Shani · Answer

I dont think that files are protected. Because if i try out the code you provided before works fine and deletes file...here is the whole thing... using System; using System.IO; using System.Windows.Forms; using System.Collections; namespace Files_ExtLib1 { public class FolderWatcher { string m_FolderPath; public FolderWatcher() { // // TODO: Add constructor logic here // } #region Property public string FolderPath { get { return m_FolderPath; } set { m_FolderPath = value; } } #endregion /// /// Deletes the files older the days hours and /// minutes specified /// /// /// /// /// Number of files deleted //public int DeleteFilesOlderThan(int Days int Hrs int Mins) //{ // string[] oldFilePaths = FilesOlderThan(Days Hrs Mins); // int count = 0; // foreach (string filePath in oldFilePaths) // { // try // { // File.Delete(filePath); // count++; // } // catch (Exception e) // { // Console.WriteLine(Unable to delete  + filePath); // Console.WriteLine(Reason: {0} e); // //Console.WriteLine(Detected an exception!!!
 + e ); // } // Console.WriteLine(Files successfully deleted); // } // // presumably number of files deleted to be returned // return count; //} /// /// Reurns filenames having last modified time older than /// specified period. /// /// /// /// /// //public string[] FilesOlderThan(int Days int Hrs int Mins) //{ // TimeSpan ts = new TimeSpan(Days Hrs Mins 0); // ArrayList oldFilePaths = new ArrayList(); // // FolderPath is assumed to be path being watched // string[] filePaths = Directory.GetFiles(FolderPath); // DateTime currentDate = DateTime.Now; // foreach (string filePath in filePaths) // { // DateTime lastWriteDate = File.GetLastWriteTime(filePath); // if ((currentDate - lastWriteDate) > ts) // { // oldFilePaths.Add(filePath); // } // } // return (string[])oldFilePaths.ToArray(typeof(string)); //} public int DeleteFilesOlderThan(int Days int Hrs int Mins string filter) { DateTime dt = GetRelativeDateTime(Days Hrs Mins); ArrayList oldFilePaths = FilesOlderThan(dt filter); int count = 0; string message = null; foreach (string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch (Exception e) { message = Unable to delete  + filePath + 
; message += String.Format(Reason: {0} e.Message); MessageBox.Show(message); // Error..Property or indexer 'System.Exception.Message' cannot be assigned to--it is read only //e.Message = Unable to delete  + filePath + e.ToString(); //Console.WriteLine(Unable to delete  + filePath); //Console.WriteLine(Reason: {0}  e); } message = String.Format({0} ex {1} files successfully deleted count oldFilePaths.Count); MessageBox.Show(message); return count; } return count; } // Using GetRelativeDateTime as a private method instead of public however as it is only to be used internally private static DateTime GetRelativeDateTime(int days int hours int minutes) { return DateTime.Now.AddDays(-days).AddHours(-hours).AddMinutes(-minutes); } public ArrayList FilesOlderThan(DateTime dt string filter) { //m_FolderPath = @C:\CsharpTempFolder; // Using the supplied path //DirectoryInfo directory = new DirectoryInfo(Directory.GetCurrentDirectory()) DirectoryInfo directory = new DirectoryInfo(m_FolderPath); // Filter is applied to the directory.GetFiles method to get files of given extension // get FileInfos for the files in the current directory matching the filter expression FileInfo[] files = directory.GetFiles(filter); //list to hold the result ArrayList older = new ArrayList(); foreach (FileInfo file in files) { //if smaller (older) than the relative time if (file.CreationTime older.Add(file.Name); //add it to the list } return older; } } } private void DeleteFiles_Click(object sender EventArgs e) { FolderWatcher fw = new FolderWatcher(); fw.FolderPath = @C:\CsharpTempFolder; // FolderName //OpenFileDialog OpenFileDialog1 = new OpenFileDialog(); fw.DeleteFilesOlderThan(int.Parse(Textbox1.Text) int.Parse(Textbox2.Text) int.Parse(Textbox3.Text) * + filetype.SelectedItem.ToString()); // deletes everything older than specified dayshrs and mins respectively //fw.DeleteFilesOlderThan(0 0 0 *.txt); }

Alan · Answer

Hi Shani Well at least that's narrowed it down a bit ;) One thing I'd forgotten is that we changed from a console app to a windows forms app a while back and so we need to get rid of the Console.WriteLine()'s which don't work in the latter type of application. That would give us revised code as follows: public int DeleteFilesOlderThan(int Days int Hrs int Mins string filter) { DateTime dt = GetRelativeDateTime(Days Hrs Mins); ArrayList oldFilePaths = FilesOlderThan(dt filter); int count = 0; string message = null; foreach (string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch (Exception e) { message = Unable to delete  + filePath + 
; message += String.Format(Reason: {0} e.Message); MessageBox.Show(message); } } message = String.Format({0} ex {1} files successfully deleted count oldFilePaths.Count); MessageBox.Show(message); return count; } The only reasons I can think of why the files are not getting deleted is because you don't have the necessary permissions or the files are protected in some way. Anyway if you change the code and run it again we should now be able to get some more information on what the problem is.

Shani · Answer

Hi Alan I followed your suggestions. I placed breakpoints on both line and checked the code throughly. Program is running fine and its taking the correct firectory and processing files with the specific filter but in the end files are not getting deleted. I am not sure why its that. Because in the try catch statement. compiler goes through with file.delete(filepath) takes in the file and skips the catch statement which it should and then goes to line files successfully deleted. But even this msg files successfully deleted is not getting displayed. I test the program both ways with breakpoints. Once by assigning m_FolderPath = @C:\csharp and once without that. I don't see any difference. directory takes the path correctly and filter is taking in the specific file exention as well..

Alan · Answer

In that case all I can suggest is that you place a breakpoint on this line: DirectoryInfo directory = new DirectoryInfo(m_FolderPath); and possibly this one as well: FileInfo[] files = directory.GetFiles(filter); to see if the values of m_FolderPath and filter are what you expect them to be at those points. I'm as certain as I can be that that there's no problem with the second of these two lines as it works perfectly in my own tests.

Shani · Answer

I did...still not working..

Alan · Answer

Yes but that's not going to be consistent with the FilesOlderThan() method: public ArrayList FilesOlderThan(DateTime dt string filter) //removed static { DirectoryInfo directory = new DirectoryInfo( m_FolderPath ); //use the supplied path instead //... unless you've got this line somewhere: m_FolderPath = @c:\csharp;

Shani · Answer

That's how i have it. private void DeleteFiles_Click(object sender EventArgs e) { FolderWatcher fw = new FolderWatcher(); fw.FolderPath = @c:\csharp; // FolderName //OpenFileDialog OpenFileDialog1 = new OpenFileDialog(); fw.DeleteFilesOlderThan(int.Parse(Textbox1.Text) int.Parse(Textbox2.Text) int.Parse(Textbox3.Text) * + filetype.SelectedItem.ToString()); // deletes everything older than specified dayshrs and mins respectively //fw.DeleteFilesOlderThan(0 0 0 *.txt); } and i just added the folderwatcher.cs class as it is to windows application project using project and than add class.

Alan · Answer

Where are you assigning a value to m_FolderPath? We originally had this variable defined in the FolderWatcher class but I imagine you must now have it in the Form class - otherwise you'd get a compile time error.

Shani · Answer

hmmm okay i get what you mean...another thing The code you modified for me to find files within a certain date assumes the current working directory. So I changed it to use the supplied m_FolderPath. Similarly I made the FilesOlderThan() method non-static as well. GetRelativeDateTime() on the other hand doesn't have the same problem since it doesn't reference any class variables. I made that (GetRelativeDateTime()) a private method however as it is only to be used internally. private static DateTime GetRelativeDateTime(int days int hours int minutes) { return DateTime.Now.AddDays(-days).AddHours(-hours).AddMinutes(-minutes); } public ArrayList FilesOlderThan(DateTime dt string filter) //removed static { DirectoryInfo directory = new DirectoryInfo( m_FolderPath ); //use the supplied path instead //... But its still not deleting the specified file types. I dont even think if its taking the path in anyways :(

Alan · Answer

That looks OK except that if you're using a ComboBox to get the extension (.exe .txt etc) then the last parameter of the fw.DeleteFilesOlderThan() method needs to be something like: * + comboBox1.SelectedItem.ToString() I wouldn't use the OpenFileDialog's Filter property here because as well as multiple filters it could also contain additional text to be shown in the dialog. For example it could look this: txt files (*.txt)|*.txt|All files (*.*)|*.* which we can't do anything with.

Shani · Answer

hey Alan would this work to enter days mins and hrs in the textboxes and taking extension from a combo box and when the button is pressed the files with specific extension get deleted. private void DeleteFiles_Click(object sender EventArgs e) { FolderWatcher fw = new FolderWatcher(); fw.FolderPath = @c:\csharp; // FolderName OpenFileDialog OpenFileDialog1 = new OpenFileDialog(); fw.DeleteFilesOlderThan(int.Parse(Textbox1.Text) int.Parse(Textbox2.Text) int.Parse(Textbox3.Text) OpenFileDialog1.Filter); // deletes everything older than specified dayshrs and mins respectively }

Shani · Answer

well instead of using button eventhandler. now i just added 3 textboxes in mah form which takes in days hrs and mins and then i added a combo box and in that i given files type e.g .txt .exe .log etc and then i guess i would place a button that would take all those param values in and test the code to create files i will try doing your way tomo Thanks Alan :)

Alan · Answer

To create multiple files you can either run that code in a loop (using filenames of output1.txt output2.txt etc) or simply copy the first file to a different file every minute. It's a very tedious way of doing things in my view but it beats messing around with the system time or hacking file properties directly. A much better way as I've said before is to copy existing files to the temporary directory. Although you can specify multiple filters with the standard .NET dialog boxes by separating them with an | character this doesn't appear to be possible with the DirectoryInfo.GetFiles method which can only process one filter at a time. The code for DeleteFiles_Click should delete all files in the current directory (unless you've changed it to specify fw.FolderPath) with an extension of .txt. Is it deleting files with other extensions as well?

Shani · Answer

Is something wrong with this? its not deleting specified file types private void DeleteFiles_Click( object sender EventArgs e) { FolderWatcher fw = new FolderWatcher (); fw.FolderPath = @c:\csharp ; // FolderName fw.DeleteFilesOlderThan(0 0 0 *.txt ); // deletes everything older than specified dayshrs and mins respectively }

Shani · Answer

Thanks for all the help so far.. 1. Resolved the first issue creating dummy files this is the piece of code i wrote to using streamwriter to get some clue the way you told me using System; using System.IO; class FileTest { static void Main() { StreamWriter outStream = null; string filename = output.txt; try { outStream = new StreamWriter(filename); outStream.WriteLine(Hello World); outStream.Close(); } catch (Exception e) { Console.WriteLine(Unable to create file {0} filename); Console.WriteLine(Reason: {0} e); return; } Console.WriteLine(File successfully created); } } can i transform this to create dummy files for me..but just confused how can i create multiple files another thing i was just thinking about Are you only allowed to define one pattern? ie *.txt? Or can you define multiple patterns? ie *.txt; *.exe; *.log?

Alan · Answer

Taking those questions in order: 1. If you've added the source code file Filewatcher.cs to your Windows Forms project and included the line: using Files; in form1.cs (and from any other file from which it is used) then you should be able to access the FileWatcher class OK. There shouldn't be any need to compile it separately as a dll. If you can't get it work try pasting the code directly into form1.cs. 2. As there's no particular reason to prefer an ArrayList to an ordinary array here yes I think it would be better to return an ArrayList from the FilesOlderThan() method. 3. It's simply a matter of taste whether you prefer the TimeSpan or 'relative date' approach. Personally I thought the latter was more elegant so as you had it to start with I'd stick with that. 4. I'll answer this later in the post as I'm going to recode the methods to find only files with a given extension. 5. The problem with the dummy files is to get a decent spread of 'last modifed' times and the only practical way to achieve that is copy existing files from another folder which you can do programatically using File.Copy(). I suppose you could augment these by creating new files programatically with any extension you like and save them to disk using the StreamWriter class. I'd just save them all as text files (using some arbitrary piece of text) as the principle of deleting them is the same whether they're text or binary. However you'd need to insert a delay of at a minute between each file creation using Thread.Sleep(60000) so the timestamps were distinct. 6. You'd either need three textboxes to enter the days hours and minutes or a single text box containing all three which you could parse into its constituents. You'd also need another textbox containing the folder to be watched. The current time can be obtained from the DateTime.Now property. 7. A filter needs to be applied to the Directory.GetFiles method to get files of a given extension which means recoding the methods to allow for this and the other points mentioned earlier: public int DeleteFilesOlderThan(int Days int Hrs int Mins string filter) { DateTime dt = GetRelativeDateTime(Days Hrs Mins); ArrayList oldFilePaths = FilesOlderThan(dt filter); int count = 0; foreach (string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch (Exception e) { Console.WriteLine(Unable to delete  + filePath); Console.WriteLine(Reason: {0} e); //Console.WriteLine(Detected an exception!!!
 + e ); } Console.WriteLine(Files successfully deleted); } return count; } public static DateTime GetRelativeDateTime(int days int hours int minutes) { return DateTime.Now.AddDays(-days).AddHours(-hours).AddMinutes(-minutes); } public static ArrayList FilesOlderThan(DateTime dt string filter) { DirectoryInfo directory = new DirectoryInfo(Directory.GetCurrentDirectory()); FileInfo[] files = directory.GetFiles(filter); //get FileInfos for the files in the current directory matching the filter expression ArrayList older = new ArrayList(); //list to hold the result foreach (FileInfo file in files) { if (file.CreationTime older.Add(file.Name); //add it to the list } return older; } So to get all exe files you would specify a filter parameter of *.exe when calling DeleteFilesolderThan txt files would require a filter of *.txt and all files would be *.*.

Shani · Answer

hey Alan:) I again need help with couple of things. You helped me with methodss in FolderWatcher.cs class posting the whole thing again. using System; using System.IO; using System.Collections; namespace Files { public class FolderWatcher { string m_FolderPath; public FolderWatcher() { // // TODO: Add constructor logic here // } #region Property public string FolderPath { get { return m_FolderPath; } set { m_FolderPath = value; } } #endregion /// /// Deletes the files older the days hours and /// minutes specified /// /// /// /// /// Number of files deleted public int DeleteFilesOlderThan(int Days int Hrs int Mins) { string[] oldFilePaths = FilesOlderThan(Days Hrs Mins); int count = 0; foreach (string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch (Exception e) { Console.WriteLine(Unable to delete  + filePath); Console.WriteLine(Reason: {0} e); //Console.WriteLine(Detected an exception!!!
 + e ); } Console.WriteLine(Files successfully deleted); } // presumably number of files deleted to be returned return count; } /// /// Reurns filenames having last modified time older than /// specified period. /// /// /// /// /// public string[] FilesOlderThan(int Days int Hrs int Mins) { TimeSpan ts = new TimeSpan(Days Hrs Mins 0); ArrayList oldFilePaths = new ArrayList(); // FolderPath is assumed to be path being watched string[] filePaths = Directory.GetFiles(FolderPath); DateTime currentDate = DateTime.Now; foreach (string filePath in filePaths) { DateTime lastWriteDate = File.GetLastWriteTime(filePath); if ((currentDate - lastWriteDate) > ts) { oldFilePaths.Add(filePath); } } return (string[])oldFilePaths.ToArray(typeof(string)); } } } I created a Windows Application project. When I am trying to access FolderWatcher.cs class I get an error saying that the type or namespace 'Files' could not be found even though I am adding 'using Files;' namespace in my windows application both in the program.cs and form1.cs. Isn't that enough. Do I need to compile FolderWatcher.cs class and then add a dll reference to the windows application project? Other stuff....returning arraylist insted of string[] better? You used Timespan object where as I used DateTime in my peice of code: public static DateTime GetRelativeDateTime(int days int hours int minutes) { return DateTime.Now.AddDays(-days).AddHours(-hours).AddMinutes(-minutes); } public static string[] FilesOlderThan(DateTime dt) { DirectoryInfo directory = new DirectoryInfo(Directory.GetCurrentDirectory()); FileInfo[] files = directory.GetFiles(); //get FileInfos for the files in the current directory ArrayList older = new ArrayList(); //list to hold the result foreach (FileInfo file in files) { if (file.CreationTime older.Add(file.Name); //add it to the list } } I want to know the difference between both timespan and datetime. Why use timeSpan? DateTime good? how do I add a deleteFilesOlderThan method using date time object? Moreover I have three buttons on my form 1. Create Test Files 2. Test 1 3. Test 2 You told me to test the code with the dummy files I did that and it worked. My colleague want me to test it differently. Firstly I want to add method in the create test files button handler that will create dummy test files for me (specific files .txt .exe .log etc.). Secondly when i click on the test 1 button handler it let me enter theX number of days mins hrs and then delete files also want to know the time and resouce. lastly in the test 2 button handler i want a method that will delte specific file types e.g .txt files only or .exe or .log I throw so much on you. hope you can help!!!! Thanks alot

Shani · Answer

Thanks for all the help Alan :)

Alan · Answer

Yes it would be easiest to test this code with a console application. As well as the code you've already got you just need to place a 'main' class inside your namespace similar to the following: class Program { static void Main() { FolderWatcher fw = new FolderWatcher(); fw.FolderPath = @c:\my documents	emp; // or whatever fw.DeleteFilesOlderThan(1000); // deletes everything older than 10 days } } You'll then just need to change the parameters to the DeleteFilesOlderThan() method. I'd be inclined to just change them in the source code and rebuild. Alternatively you could pass them in as command line arguments to the executable: static void Main(string[] args) { FolderWatcher fw = new FolderWatcher(); fw.FolderPath = @c:\my documents	emp; // or whatever int days = int.Parse(args[0]); int hrs = int.Parse(args[1]); int mins = int.Parse(args[2]); fw.DeleteFilesOlderThan(dayshrsmins); }

Shani · Answer

hmm okay i created the folder and dumped in random txt files into it how do i check it with the class 'FolderWatcher.cs' :S.....do i have to write a console application for it or something else....my apologies for asking these kind of questions :$

Alan · Answer

Hi Shani Yes I'd create a new folder and copy some files into it so that you get a variety of 'last written' times. You can also create some new ones if you like - just type a few words into notepad and save that. You can then try different time intervals. If you start with the longest first and then gradually shorten it your files should decrease in number until there are none left. To be on the safe side I'd repeat the whole exercise three times. If no bugs show up it should be safe to use (famous last words!).

Shani · Answer

yup yup I was just about to ask you that. Thanks for noticing :) one more thing like you said that i should test the code on a dummy folder before let it loose on real data. I want to test it first before i forward it to my team. What do i do? like create dummy files in a specified folder and try it out play with time by changing the date and time on my laptop. how do i create different test cases to test out the code? just kind of shaky on this...it just new to me and seeking your help Thanks

Alan · Answer

Yeah the code looks to have slotted in nicely :) In fact I think what you already had should work OK too. The 'relative date' idea (as opposed to the TimeSpan which I've used) is a neat one. EDIT: Just one point on the FilesOlderThan() method. It says in the comments that this relates to the date the files were last modified as opposed to created. If that's the case then you need to change this bit of code: DateTime creationDate = File.GetCreationTime(filePath); if ((currentDate - creationDate) > ts) { oldFilePaths.Add(filePath); } to this: DateTime lastWriteDate = File.GetLastWriteTime(filePath); if ((currentDate - lastWriteDate) > ts) { oldFilePaths.Add(filePath); }

Shani · Answer

Thanks for your time Alan :) your always so helpful. I wrote the commented out code because i thought it would make it easier if i use a DateTime structure to represent the date and time. Anyways I want to try out your code....Just want you to have a look at the whole thing before i try it. Thanks!!! using System; using System.IO; using System.Windows.Forms; using System.Collections; namespace Files_ExtLib1 { /// /// Summary description for FolderWatcher. /// public class FolderWatcher { string m_FolderPath; public FolderWatcher() { // // TODO: Add constructor logic here // } #region Property public string FolderPath { get { return m_FolderPath; } set { m_FolderPath = value; } } #endregion /// /// Deletes the files older the days hours and /// minutes specified /// /// /// /// /// Number of files deleted public int DeleteFilesOlderThan(int Days int Hrs int Mins) { string[] oldFilePaths = FilesOlderThan(Days Hrs Mins); int count = 0; foreach(string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch { MessageBox.Show(Unable to delete  + filePath); } } // presumably number of files deleted to be returned return count; } /// /// Reurns filenames having last modified time older than /// specified period. /// /// /// /// /// public string[] FilesOlderThan(int Days int Hrs int Mins) { TimeSpan ts = new TimeSpan(Days Hrs Mins 0); ArrayList oldFilePaths = new ArrayList(); // FolderPath is assumed to be path being watched string[] filePaths = Directory.GetFiles(FolderPath); DateTime currentDate = DateTime.Now; foreach(string filePath in filePaths) { DateTime creationDate = File.GetCreationTime(filePath); if ((currentDate - creationDate) > ts) { oldFilePaths.Add(filePath); } } return (string[])oldFilePaths.ToArray(typeof(string)); } // public static DateTime GetRelativeDateTime(int days int hours int minutes) // { // return DateTime.Now.AddDays(-days).AddHours(-hours).AddMinutes(-minutes); // } // public static string[] FilesOlderThan(DateTime dt) // { // DirectoryInfo directory = new DirectoryInfo(Directory.GetCurrentDirectory()); // FileInfo[] files = directory.GetFiles(); //get FileInfos for the files in the current directory // ArrayList older = new ArrayList(); //list to hold the result // foreach (FileInfo file in files) // { // if (file.CreationTime // older.Add(file.Name); //add it to the list // } // return (string[])older.ToArray(typeof(string)); //return as an array // } } }

Alan · Answer

Here's some basic code to do this. Please test this thoroughly on a 'dummy' folder before you let it loose on real data as deleting files in bulk makes me nervous! using System; using System.IO; using System.Windows.Forms; using System.Collections; // .......... public int DeleteFilesOlderThan(int Days int Hrs int Mins) { string[] oldFilePaths = FilesOlderThan(Days Hrs Mins); int count = 0; foreach(string filePath in oldFilePaths) { try { File.Delete(filePath); count++; } catch { MessageBox.Show(Unable to delete  + filePath); } } // presumably number of files deleted to be returned return count; } public string[] FilesOlderThan(int Days int Hrs int Mins) { TimeSpan ts = new TimeSpan(Days Hrs Mins 0); ArrayList oldFilePaths = new ArrayList(); // FolderPath is assumed to be path being watched string[] filePaths = Directory.GetFiles(FolderPath); DateTime currentDate = DateTime.Now; foreach(string filePath in filePaths) { DateTime creationDate = File.GetCreationTime(filePath); if ((currentDate - creationDate) > ts) { oldFilePaths.Add(filePath); } } return (string[])oldFilePaths.ToArray(typeof(string)); }