Monitoring file changes and changing data within the file... - C# Discussion Boards

Matt T Heffron2-Oct-12 10:38

Matt T Heffron

2-Oct-12 10:38

Your ValidateText will set the Successful to indicate if the last entry in the textbox list is valid or not. All the checking of the earlier entries is lost.
Try something like:

public void ValidateText(List<TextBox> textboxes)
{
  Successful = true;    // Assume all are valid until shown otherwise
  foreach (var tb in textboxes)
  {
    if (string.IsNullOrEmpty(tb.Text))  // could also use .IsNullOrWhiteSpace()
    {
      Successful = false;       // this means that at least 1 is failing.
      // collect the failing ones here
    }
  }
}

and then

List<TextBox> textboxes = new List<TextBox>();
textboxes.Add(FirstNTxt);
textboxes.Add(LastNTxt);
textboxes.Add(CourseTxt);
//validation
FormValidation validate = new FormValidation();
validate.ValidateText(textboxes);
if(!validate.Successful)
{
  MessageBox.Show("error");
}
else
{
  //more stuff that i did not paste in.
}

Personally, I'd probably make a validation method that operates on one string at a time and then validate and set the errorprovider directly for each TextBox one at a time. (Despite what I showed above, I wouldn't pass the actual TextBox references around. The method should validate the string, possibly returning an error message. The caller (form) passes the .Text and reports the error appropriately.)

Smart Arab2-Oct-12 11:17

Smart Arab

2-Oct-12 11:17

This code well search for all text box in your form and validated it, and it will be better If you Use Tag for Description of Textbox so the user know what he is missing, Plus you avoid typing in the MessageBox something like "No Name" , No Phone" , etc ...

More Over you can tell which TextBox in the form is needed to be validate by checking that Tag if it's Empty or not.

private void CheckTextBox()
       {
           TxtName.Tag = "First Name";
           TxtPhone.Tag = "Phone Number";

           foreach (Control control in this.Controls)
           {
               if (control.GetType().Equals(typeof(TextBox)))
               {
                   if (ValidateText(control.Text))
                   {
                       MessageBox.Show(control.Tag.ToString());
                       MessageBox.Show(control.Name);
                   }

               }
           }
       }

       private bool ValidateText(string text)
       {
           return text.Equals(string.Empty);
       }

P.S :
You can assign the Tag for TextBox by properties Windows during design time.

User 94041062-Oct-12 11:27

User 9404106

2-Oct-12 11:27

Two fantastic suggestions. Thank you so much. Both of these solve the issue I was facing.

Once again, Thanks!

modified 11-Mar-21 21:01pm.

Monitoring file changes and changing data within the file...

User 94041068-Oct-12 3:37

User 9404106

8-Oct-12 3:37

Sorry, i just got around to trying both methods. For the first one,

public void ValidateText(List textboxes)
{
  Successful = true;    // Assume all are valid until shown otherwise
  foreach (var tb in textboxes)
  {
    if (string.IsNullOrEmpty(tb.Text))  // could also use .IsNullOrWhiteSpace()
    {
      Successful = false;       // this means that at least 1 is failing.
      // collect the failing ones here
    }
  }
}

how do i go about outputting the actual control name that failed? all i can do is echo tb.text which ofc is empty. Any help would be great.

modified 11-Mar-21 21:01pm.

JD862-Oct-12 8:31

JD86

2-Oct-12 8:31

What would be a good way to monitor a .ini file?

What I want to do is when the file has changed, I need to read the file and find specific text and change it and save the file.

I've attempted the file system watcher with little luck. The problem is it is firing before the file is unlocked. I have also tried to put a method in there to check if the file was locked which basically opens the file and on exception returns true if locked otherwise false.

I have also tried a looping method like this:

private void WriteFile(string file, StringBuilder sb, string oldValue)
        {
            StreamWriter sw = null;
            try
            {
                sw = new StreamWriter(file, false);
                sw.Write(sb.ToString());
                sw.Close();

                // Log
                EventLog.WriteEntry("QBiniMonitor", "Successfully removed LASTUSERNAME. Old Value: " + oldValue, EventLogEntryType.Information);
            }
            catch (IOException)
            {
                // Keep trying till the file is unlocked
                WriteFile(file, sb, oldValue);
            }
            finally
            {
                if (sw != null)
                {
                    sw.Close();
                    sw.Dispose();
                }
            }
        }

It still errored out after it changes the value a couple times in a row. It changes it a couple times but then ends up with a uncaught IOException somehow

Re: Monitoring file changes and changing data within the file...

Smart Arab2-Oct-12 11:22

Smart Arab

2-Oct-12 11:22

You can use this method in a loop until the ini file closed.

protected virtual bool IsFileLocked(FileInfo file)
{
    FileStream stream = null;

    try
    {
        stream = file.Open(FileMode.Open, FileAccess.ReadWrite, FileShare.None);
    }
    catch (IOException)
    {
        //the file is unavailable because it is:
        //still being written to
        //or being processed by another thread
        //or does not exist (has already been processed)
        return true;
    }
    finally
    {
        if (stream != null)
            stream.Close();
    }

    //file is not locked
    return false;
}

Re: Monitoring file changes and changing data within the file...

Pete O'Hanlon3-Oct-12 2:03

Re: Monitoring file changes and changing data within the file...

3-Oct-12 2:03

The OP could try this, but there's a race condition here. What happens if he calls this method, and it returns false, and then he opens the file but an external process has taken a lock on the file?

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

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Eddy Vluggen3-Oct-12 1:39

Eddy Vluggen

3-Oct-12 1:39

JD86 wrote:
It changes it a couple times but then ends up with a uncaught IOException somehow

catch (IOException)
{
    // Log the exception here!!

    // Keep trying till the file is unlocked
    WriteFile(file, sb, oldValue);
}

You should log all exceptions; I'm betting that your WriteFile is causing the new exception, which would throw something "unhandled". So, wrap that in a try-construction too, or move it somewhere else.

I'd also recommend using a using block, as opposed to a try-finally with explicit dispose - it's a bit more readable.

Bastard Programmer from Hell Suspicious | :suss:

if you can't read my code, try converting it here[^]

Re: Monitoring file changes and changing data within the file...

Pete O'Hanlon3-Oct-12 2:26

Re: Monitoring file changes and changing data within the file...

3-Oct-12 2:26

I would be tempted to rewrite this method like this:

private static readonly object SyncLock = new object();
private void WriteFile(string file, StringBuilder sb, string oldValue)
{
  try
  {
    using (StreamWriter sw = new StreamWriter(file, false))
    {
      sw.Write(sb.ToString());
    }
    // Log
    EventLog.WriteEntry("QBiniMonitor", "Successfully removed LASTUSERNAME. Old Value: " + oldValue, EventLogEntryType.Information);
  }
  catch (IOException)
  {
    lock (SyncLock)
    {
      // Wait for 200 milliseconds
      Monitor.Wait(SyncLock, 200);
    }
    // Keep trying till the file is unlocked
    WriteFile(file, sb, oldValue);
  }
}

The using statement removes the need to explicitly close the stream, and the lock/Monitor elements help to pause the next call to WriteFile for 200 milliseconds. Without this, you have a tight loop in there with execution of WriteFile happening immediately on failure.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Dave Kreskowiak3-Oct-12 5:33

Re: Monitoring file changes and changing data within the file...

3-Oct-12 5:33

Whoa there Slick! I see a possible StackOverflow waiting to happen if the file never gets unlocked.

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Dave Kreskowiak

Pete O'Hanlon3-Oct-12 5:37

Re: Monitoring file changes and changing data within the file...

3-Oct-12 5:37

Indeed, but I'm only working with the OPs original code - yes, if it were my code, I'd add in terminating conditions. As I don't know what the OPs ultimate use case is here, I'm loathe to suggest this - I've just had to assume that the lock has a finite limit.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Dave Kreskowiak3-Oct-12 13:38

Re: Monitoring file changes and changing data within the file...

3-Oct-12 13:38

Pete O'Hanlon wrote:
I've just had to assume that the lock has a finite
limit.

True. I don't know any more about his requirements than you. I just wanted to point out that it's not the ultimate solution for anyone else just scrounging for code.

Pete O'Hanlon wrote:
I'm loathe to suggest this

Kinda makes you want to take a long shower, doesn't it? Wink | ;)

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

BobJanova3-Oct-12 2:42

BobJanova

3-Oct-12 2:42

Use the FileSystemWatcher, when it notifies you of a change put an entry on a queue with a retrieval time of 1 second (or 200ms or whatever is appropriate in the future), and have another thread which pulls things off that queue at the right time and actions them. In this case the action is 'read file, find text, replace, write file'. If it fails, re-queue it.

Re: Monitoring file changes and changing data within the file...

Pete O'Hanlon3-Oct-12 3:10

Re: Monitoring file changes and changing data within the file...

3-Oct-12 3:10

Based on the description, I believe this is what the OP has said he's done (all except for the pause bit).

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

JD863-Oct-12 13:59

JD86

3-Oct-12 13:59

Sorry for the delay responses! Just had a baby girl Smile | :)

Anyways let me explain. I'm setting up a multi-tenant quickbooks environment. The problem is as we probably all know is it wasn't really designed for multi-tenancy. Now everything works fine with what I have except the username is populated on a program level.

So in the ProgramData directory (All Users) there is a qbw.ini file that contains LASTUSERNAME=. Each time a user launches quickbooks it reads this information and prepopulated the username field for the company database login.

I don't want people seeing other peoples logins. Most just use Admin which isn't a big deal but some use their company name. So I don't want another company seeing that.

So my idea is to monitor that file for updates using a file system watcher and changing that value in the INI file to blank. So basically changing something like this: "LASTUSERNAME=Admin" to this: "LASTUSERNAME="

Quickbooks does not place a permanent lock on this file. So we don't have to worry about quickbooks locking it for a long period of time.

I'm trying suggestions as we speak. I'm adding an error count to stop the service if an exception happens so many times within a specific time period. Hopefully this will stop an overflow exception like you were talking about. I can make something to restart the service ever so often.

Not the best plan but so far thats what I got!

Re: Monitoring file changes and changing data within the file...

JD8612-Oct-12 5:27

JD86

12-Oct-12 5:27

Alright so here is what I ended up with. It seems to work... catches the IO exceptions and continues running. So far it is working good enough for me

using System;
using System.Diagnostics;
using System.IO;
using System.ServiceProcess;
using System.Text;
using System.Threading;

namespace QBiniMonitor
{
    public partial class QBMonitor : ServiceBase
    {
        // Watches the qbw.ini directory
        FileSystemWatcher watcher2012;
        FileSystemWatcher watcher2011;

        // Path to the folder where qbw.ini is stored
        string QB2012 = Environment.ExpandEnvironmentVariables("%ALLUSERSPROFILE%") + @"\Intuit\QuickBooks 2012\";
        string QB2011 = Environment.ExpandEnvironmentVariables("%ALLUSERSPROFILE%") + @"\Intuit\QuickBooks 2011\";

        // Version
        enum Version
        {
            QB2011,
            QB2012
        }

        /// <summary>
        /// Constructor
        /// </summary>
        public QBMonitor()
        {
            InitializeComponent();
        }

        /// <summary>
        /// When service starts we need to start our FileSystemWatcher
        /// </summary>
        protected override void OnStart(string[] args)
        {
            StartNewWatcher(Version.QB2011);
            StartNewWatcher(Version.QB2012);
        }

        /// <summary>
        /// Starts the FileSystemWatcher for Quickbooks 2012 & 2011
        /// </summary>
        private void StartNewWatcher(Version watcherVersion)
        {
            if (watcherVersion == Version.QB2011)
            {
                watcher2011 = new FileSystemWatcher();
                watcher2011.Path = QB2011;
                watcher2011.Filter = "qbw.ini";
                watcher2011.NotifyFilter = NotifyFilters.LastWrite;

                watcher2011.Changed += new FileSystemEventHandler(watcher_Changed);

                // Start the watcher
                StartStopWatcher(Version.QB2011, true);
            }
            else if (watcherVersion == Version.QB2012)
            {
                watcher2012 = new FileSystemWatcher();
                watcher2012.Path = QB2012;
                watcher2012.Filter = "qbw.ini";
                watcher2012.NotifyFilter = NotifyFilters.LastWrite;

                watcher2012.Changed += new FileSystemEventHandler(watcher_Changed);

                // Start the watcher
                StartStopWatcher(Version.QB2012, true);
            }
        }

        /// <summary>
        /// When the file is written to we need to remove the last username
        /// </summary>
        private void watcher_Changed(object sender, FileSystemEventArgs e)
        {
            // Get our file system watcher object
            FileSystemWatcher watcher = sender as FileSystemWatcher;

            // Find what version it is and stop the file system watcher
            if (watcher.Path == QB2012)
                StartStopWatcher(Version.QB2012, false);
            else if (watcher.Path == QB2011)
                StartStopWatcher(Version.QB2011, false);

            // Variable if we should change the file or not
            bool saveFile = false;

            // Variable that keeps our old value
            string oldValue = string.Empty;

            // Contains all the text in the file when we read it
            StringBuilder sb = new StringBuilder();

            try
            {
                using (FileStream fs = new FileStream(e.FullPath, FileMode.Open, FileAccess.Read))
                {
                    using (StreamReader sr = new StreamReader(fs))
                    {
                        while (sr.Peek() >= 0)
                        {
                            // Read the current line
                            string currentLine = sr.ReadLine();

                            // If the line is LASTUSERNAME we need to make sure the value is Admin.
                            if (currentLine.StartsWith("LASTUSERNAME="))
                            {
                                // If the line is not just LASTUSERNAME=Admin then change it
                                if (!currentLine.Equals("LASTUSERNAME=Admin"))
                                {
                                    // LASTUSERNAME contains a value. We must change
                                    sb.AppendLine("LASTUSERNAME=Admin");

                                    // Log what the previous value was
                                    oldValue = currentLine;

                                    // Only save file if we change data
                                    saveFile = true;
                                }
                                else
                                    sb.AppendLine(currentLine); // Value is LASTUSERNAME=Admin (blank) so we are good
                            }
                            else
                                sb.AppendLine(currentLine); // Does not start with LASTUSERNAME=Admin
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                EventLog.WriteEntry("QBiniMonitor", "watcher_Changed::: " + ex.ToString(), EventLogEntryType.Error);
            }

            // If we are supposed to save the file then call WriteFile
            if (saveFile)
            {
                // If we are here that means LASTUSERNAME has a value and we must remove it
                if (watcher.Path == QB2012)
                    WriteFile(Version.QB2012, e.FullPath, sb, oldValue, 1);
                else if (watcher.Path == QB2011)
                    WriteFile(Version.QB2011, e.FullPath, sb, oldValue, 1);
            }
            else
            {
                if (watcher.Path == QB2012)
                    StartStopWatcher(Version.QB2012, true);
                else if (watcher.Path == QB2011)
                    StartStopWatcher(Version.QB2011, true);
            }
        }

        private static readonly object SyncLock = new object();
        private void WriteFile(Version watcherVersion, string file, StringBuilder sb, string oldValue, int retryCount)
        {
            if (retryCount < 5)
            {
                try
                {
                    using (StreamWriter sw = new StreamWriter(file, false))
                    {
                        // Write the file
                        sw.Write(sb.ToString());
                    }

                    // Log
                    EventLog.WriteEntry("QBiniMonitor", "Version: " + watcherVersion.ToString() + ". The value for the last username was cleared. The previous value was: " + oldValue, EventLogEntryType.Information);

                    // Start watching again
                    StartStopWatcher(watcherVersion, true);
                }
                catch (IOException)
                {
                    // Wait for 1 seconds before trying again
                    lock (SyncLock)
                    {
                        EventLog.WriteEntry("QBiniMonitor", "Version: " + watcherVersion.ToString() + ". File was locked. Waiting 2 seconds and trying again. Retry number: " + retryCount);
                        Monitor.Wait(SyncLock, 2000);
                    }

                    // Increase the retry count
                    retryCount = retryCount + 1;

                    // Call our method to try to write the file again
                    WriteFile(watcherVersion, file, sb, oldValue, retryCount);
                }
            }
            else
            {
                // Reached our retry limit so stop trying
                EventLog.WriteEntry("QBiniMonitor", "WriteFile::: " + "Retry limit of 5 was reached while trying to change the data in the file. (Because the file was locked)", EventLogEntryType.Warning);

                // Start watching again
                StartStopWatcher(watcherVersion, true);
            }
        }

        /// <summary>
        /// Starts or stops the file system watcher
        /// </summary>
        /// <param name="watcherVersion"></param>
        /// <param name="start"></param>
        private void StartStopWatcher(Version watcherVersion, bool start)
        {
            try
            {
                switch (watcherVersion)
                {
                    case Version.QB2011:
                        if (start)
                        {
                            watcher2011.EnableRaisingEvents = true;
                            //EventLog.WriteEntry("QBiniMonitor", "Started watching file " + watcher2011.Path + "\\" + watcher2011.Filter, EventLogEntryType.Information);
                        }
                        else
                        {
                            watcher2011.EnableRaisingEvents = false;
                            //EventLog.WriteEntry("QBiniMonitor", "Stopped watching file " + watcher2011.Path + "\\" + watcher2011.Filter, EventLogEntryType.Information);
                        }
                        break;

                    case Version.QB2012:
                        if (start)
                        {
                            watcher2012.EnableRaisingEvents = true;
                            //EventLog.WriteEntry("QBiniMonitor", "Started watching file " + watcher2012.Path + "\\" + watcher2012.Filter, EventLogEntryType.Information);
                        }
                        else
                        {
                            watcher2012.EnableRaisingEvents = false;
                            //EventLog.WriteEntry("QBiniMonitor", "Stopped watching file " + watcher2012.Path + "\\" + watcher2012.Filter, EventLogEntryType.Information);
                        }
                        break;

                    default:
                        break;
                }
            }
            catch (IOException ex)
            {
                // Log the error in the event log
                EventLog.WriteEntry("QBiniMonitor", "StartStopWatcher::: " + ex.ToString(), EventLogEntryType.Error);

                // Stop because of error (most likely because we couldn't find the file)
                Stop();
            }
            catch (Exception ex)
            {
                // Log the error in the event log
                EventLog.WriteEntry("QBiniMonitor", "StartStopWatcher::: " + ex.ToString(), EventLogEntryType.Error);

                // Stop because of error (most likely because we couldn't find the file)
                Stop();
            }
        }

        /// <summary>
        /// When the service stops
        /// </summary>
        protected override void OnStop()
        {
            if (watcher2011 != null)
            {
                watcher2011.EnableRaisingEvents = false;
                watcher2011.Dispose();
            }

            if (watcher2012 != null)
            {
                watcher2012.EnableRaisingEvents = false;
                watcher2012.Dispose();
            }
        }
    }
}

C# setup and deploy project templates located at?

dcof2-Oct-12 5:10

dcof

2-Oct-12 5:10

I have a C# 2010 console application where I need to create a setup and deployment project for it. I do not have the setup and deployment projects in the visual studio.net 2010 application I am using. I need to find the install templates.

Can you tell me where I can find the setup and deployment project install templates so I can add them to my solution ide to work with?

Re: C# setup and deploy project templates located at?

isenthil2-Oct-12 6:30

isenthil

2-Oct-12 6:30

You should find them in the Other Projects ( Project Templates )

Create a new Project of type (Other Projects - > Setup and Deployment -> VS Installer) ...

Regards,
Senthil Kumar

Re: C# setup and deploy project templates located at?

dcof2-Oct-12 17:48

dcof

2-Oct-12 17:48

I do not have a Create a new Project of type (Other Projects - > Setup and Deployment -> VS Installer). I am somehow missing the templates.

Re: C# setup and deploy project templates located at?

Dave Kreskowiak3-Oct-12 2:28

Re: C# setup and deploy project templates located at?

3-Oct-12 2:28

If you have an Express version of Visual Studio you won't have it.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak

Dave Kreskowiak2-Oct-12 12:33