How to check for file size changes only after the file created using filesystemwatcher ?

Question

The problem is once a file is created it's displaying the file creation time in the Fsw_Created event but then also display that the file size has changed in the Fsw_Changed event.
I want somehow to make that if a file was created first time don't display any changes only after the file was created then if something changed in the file then display it in the Fsw_Changed event.

Maybe to remember some stuff in the Fsw_Created event for each file and then check for it in the Fsw_Changed event ?
I'm not sure how to solve it.

The created event :

private void Fsw_Created(object sender, FileSystemEventArgs e)
        {
            string time = DateTime.Now.ToString("h:mm:ss tt");
            if (!richTextBoxLogChanges.Text.Contains(e.FullPath))
            {
                AppendText(richTextBoxLogChanges, $"File Name : {e.Name} ", Color.Red);
                AppendText(richTextBoxLogChanges, $"Created At : {time}", Color.Yellow);
                AppendText(richTextBoxLogChanges, "\n", Color.LightGreen);
            }
        }

The changed event :

        private void Fsw_Changed(object sender, FileSystemEventArgs e)
        {
            if (e.ChangeType != WatcherChangeTypes.Changed)
            {
                return;
            }
            else
            {
                var info = new FileInfo(e.FullPath);
                var theSize = info.Length;
                var size = SizeSuffix(theSize);

                string FileN1 = "File Name : ";
                string FileN2 = info.Name;
                string FileN3 = " Size Changed : ";
                string FileN4 = size;

                if (!richTextBoxLogChanges.Text.Contains(FileN1 + FileN2 + FileN3 + FileN4))
                {
                    AppendText(richTextBoxLogChanges, FileN1, Color.Red);
                    AppendText(richTextBoxLogChanges, FileN2, Color.Yellow);
                    AppendText(richTextBoxLogChanges, FileN3, Color.Red);
                    AppendText(richTextBoxLogChanges, FileN4, Color.LightBlue);
                    AppendText(richTextBoxLogChanges, "\n", Color.LightGreen);
                }
            }
        }

Answer 1

@Chocolade , Welcome to Microsoft Q&A, I suggest that you could use Dictionary to store the path and file size.

I make a code example and you could refer to it.

    FileSystemWatcher watcher = new FileSystemWatcher("E:\\Test");  
    List<string> filelist = new List<string>();  
    Dictionary<string, long> dic = new Dictionary<string, long>();  
    private void Form1_Load(object sender, EventArgs e)  
    {  
        watcher.NotifyFilter = NotifyFilters.Attributes  
                            | NotifyFilters.CreationTime  
                            | NotifyFilters.DirectoryName  
                            | NotifyFilters.FileName  
                            | NotifyFilters.LastAccess  
                            | NotifyFilters.LastWrite  
                            | NotifyFilters.Security  
                            | NotifyFilters.Size;  
        watcher.Changed += Watcher_Changed;  
        watcher.Created += Watcher_Created;  
        watcher.Renamed += Watcher_Renamed;  
     
        watcher.Filter = "*.txt";  
        watcher.IncludeSubdirectories = true;  
        watcher.EnableRaisingEvents = true;  
        watcher.SynchronizingObject = this;  
  
        filelist = Directory.GetFiles("E:\\Test", "*.txt").ToList();  
        foreach (var item in filelist)  
        {  
            FileInfo info = new FileInfo(item);  
            dic.Add(item, info.Length);  
        }  
         
    }  
  
    private void Watcher_Renamed(object sender, RenamedEventArgs e)  
    {  
        FileInfo info = new FileInfo(e.FullPath);  
        if(dic.ContainsKey(e.FullPath))  
        {  
            dic[e.FullPath] = info.Length;  
        }  
        else  
        {  
            dic.Add(e.FullPath, info.Length);  
        }  
  
          
    }  
  
    private void Watcher_Created(object sender, FileSystemEventArgs e)  
    {  
        string time = DateTime.Now.ToString("h:mm:ss tt");  
  
        if (!richTextBox1.Text.Contains(e.FullPath))  
        {  
            richTextBox1.AppendText($"File Name : {e.Name} ");  
            richTextBox1.AppendText($"Created At : {time}");  
            filelist.Add(e.FullPath);  
            FileInfo info = new FileInfo(e.FullPath);  
            if (dic.ContainsKey(e.FullPath))  
            {  
                dic[e.FullPath] = info.Length;  
            }  
            else  
            {  
                dic.Add(e.FullPath, info.Length);  
            }  
        }  
    }  
  
    private void Watcher_Changed(object sender, FileSystemEventArgs e)  
    {  
        if (e.ChangeType != WatcherChangeTypes.Changed)  
        {  
            return;  
        }  
        else  
        {  
            var info = new FileInfo(e.FullPath);  
            var newSize = info.Length;  
            var oldsize = dic[e.FullPath];  
  
            string FileN1 = "File Name : ";  
            string FileN2 = info.Name;  
            string FileN3 = " Size Changed : From ";  
            string FileN4 = oldsize.ToString();  
            string FileN5 = "To";  
            string FileN6 = newSize.ToString();  
            if (newSize!=oldsize)  
            {  
                richTextBox1.AppendText(FileN1);  
                richTextBox1.AppendText(FileN2);  
                richTextBox1.AppendText(FileN3);  
                richTextBox1.AppendText(FileN4);  
                richTextBox1.AppendText(FileN5);  
                richTextBox1.AppendText(FileN6);  
                richTextBox1.AppendText("\n");  
                 
            }  
  
            if (dic.ContainsKey(e.FullPath))  
            {  
                dic[e.FullPath] = info.Length;  
            }  
            else  
            {  
                dic.Add(e.FullPath, info.Length);  
            }  
        }  
    }  

Tested Result:

Best Regards,
Jack

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