FileSystemWatcher.Created Event

Reference

Definition

Namespace:: System.IO

Assemblies:: netstandard.dll, System.IO.FileSystem.Watcher.dll

Assembly:: System.IO.FileSystem.Watcher.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Occurs when a file or directory in the specified Path is created.

public:
 event System::IO::FileSystemEventHandler ^ Created;

public event System.IO.FileSystemEventHandler? Created;

public event System.IO.FileSystemEventHandler Created;

[System.IO.IODescription("FSW_Created")]
public event System.IO.FileSystemEventHandler Created;

member this.Created : System.IO.FileSystemEventHandler

[<System.IO.IODescription("FSW_Created")>]
member this.Created : System.IO.FileSystemEventHandler

Public Custom Event Created As FileSystemEventHandler

Event Type

FileSystemEventHandler

Attributes: IODescriptionAttribute

Examples

The following example uses the Created event to display the file path to the console whenever the watched file is created.

#include "pch.h"

using namespace System;
using namespace System::IO;

class MyClassCPP
{
public:

    int static Run()
    {
        FileSystemWatcher^ watcher = gcnew FileSystemWatcher("C:\\path\\to\\folder");

        watcher->NotifyFilter = static_cast<NotifyFilters>(NotifyFilters::Attributes
                                                         | NotifyFilters::CreationTime
                                                         | NotifyFilters::DirectoryName
                                                         | NotifyFilters::FileName
                                                         | NotifyFilters::LastAccess
                                                         | NotifyFilters::LastWrite
                                                         | NotifyFilters::Security
                                                         | NotifyFilters::Size);

        watcher->Changed += gcnew FileSystemEventHandler(MyClassCPP::OnChanged);
        watcher->Created += gcnew FileSystemEventHandler(MyClassCPP::OnCreated);
        watcher->Deleted += gcnew FileSystemEventHandler(MyClassCPP::OnDeleted);
        watcher->Renamed += gcnew RenamedEventHandler(MyClassCPP::OnRenamed);
        watcher->Error   += gcnew ErrorEventHandler(MyClassCPP::OnError);

        watcher->Filter = "*.txt";
        watcher->IncludeSubdirectories = true;
        watcher->EnableRaisingEvents = true;

        Console::WriteLine("Press enter to exit.");
        Console::ReadLine();

        return 0;
    }

private:

    static void OnChanged(Object^ sender, FileSystemEventArgs^ e)
    {
        if (e->ChangeType != WatcherChangeTypes::Changed)
        {
            return;
        }
        Console::WriteLine("Changed: {0}", e->FullPath);
    }

    static void OnCreated(Object^ sender, FileSystemEventArgs^ e)
    {
        Console::WriteLine("Created: {0}", e->FullPath);
    }

    static void OnDeleted(Object^ sender, FileSystemEventArgs^ e)
    {
        Console::WriteLine("Deleted: {0}", e->FullPath);
    }

    static void OnRenamed(Object^ sender, RenamedEventArgs^ e)
    {
        Console::WriteLine("Renamed:");
        Console::WriteLine("    Old: {0}", e->OldFullPath);
        Console::WriteLine("    New: {0}", e->FullPath);
    }

    static void OnError(Object^ sender, ErrorEventArgs^ e)
    {
        PrintException(e->GetException());
    }

    static void PrintException(Exception^ ex)
    {
        if (ex != nullptr)
        {
            Console::WriteLine("Message: {0}", ex->Message);
            Console::WriteLine("Stacktrace:");
            Console::WriteLine(ex->StackTrace);
            Console::WriteLine();
            PrintException(ex->InnerException);
        }
    }
};


int main()
{
    MyClassCPP::Run();
}

using System;
using System.IO;

namespace MyNamespace
{
    class MyClassCS
    {
        static void Main()
        {
            using var watcher = new FileSystemWatcher(@"C:\path\to\folder");

            watcher.NotifyFilter = NotifyFilters.Attributes
                                 | NotifyFilters.CreationTime
                                 | NotifyFilters.DirectoryName
                                 | NotifyFilters.FileName
                                 | NotifyFilters.LastAccess
                                 | NotifyFilters.LastWrite
                                 | NotifyFilters.Security
                                 | NotifyFilters.Size;

            watcher.Changed += OnChanged;
            watcher.Created += OnCreated;
            watcher.Deleted += OnDeleted;
            watcher.Renamed += OnRenamed;
            watcher.Error += OnError;

            watcher.Filter = "*.txt";
            watcher.IncludeSubdirectories = true;
            watcher.EnableRaisingEvents = true;

            Console.WriteLine("Press enter to exit.");
            Console.ReadLine();
        }

        private static void OnChanged(object sender, FileSystemEventArgs e)
        {
            if (e.ChangeType != WatcherChangeTypes.Changed)
            {
                return;
            }
            Console.WriteLine($"Changed: {e.FullPath}");
        }

        private static void OnCreated(object sender, FileSystemEventArgs e)
        {
            string value = $"Created: {e.FullPath}";
            Console.WriteLine(value);
        }

        private static void OnDeleted(object sender, FileSystemEventArgs e) =>
            Console.WriteLine($"Deleted: {e.FullPath}");

        private static void OnRenamed(object sender, RenamedEventArgs e)
        {
            Console.WriteLine($"Renamed:");
            Console.WriteLine($"    Old: {e.OldFullPath}");
            Console.WriteLine($"    New: {e.FullPath}");
        }

        private static void OnError(object sender, ErrorEventArgs e) =>
            PrintException(e.GetException());

        private static void PrintException(Exception? ex)
        {
            if (ex != null)
            {
                Console.WriteLine($"Message: {ex.Message}");
                Console.WriteLine("Stacktrace:");
                Console.WriteLine(ex.StackTrace);
                Console.WriteLine();
                PrintException(ex.InnerException);
            }
        }
    }
}

Imports System.IO

Namespace MyNamespace

    Class MyClassVB

        Shared Sub Main()
            Using watcher = New FileSystemWatcher("C:\path\to\folder")
                watcher.NotifyFilter = NotifyFilters.Attributes Or
                                       NotifyFilters.CreationTime Or
                                       NotifyFilters.DirectoryName Or
                                       NotifyFilters.FileName Or
                                       NotifyFilters.LastAccess Or
                                       NotifyFilters.LastWrite Or
                                       NotifyFilters.Security Or
                                       NotifyFilters.Size

                AddHandler watcher.Changed, AddressOf OnChanged
                AddHandler watcher.Created, AddressOf OnCreated
                AddHandler watcher.Deleted, AddressOf OnDeleted
                AddHandler watcher.Renamed, AddressOf OnRenamed
                AddHandler watcher.Error, AddressOf OnError

                watcher.Filter = "*.txt"
                watcher.IncludeSubdirectories = True
                watcher.EnableRaisingEvents = True

                Console.WriteLine("Press enter to exit.")
                Console.ReadLine()
            End Using
        End Sub

        Private Shared Sub OnChanged(sender As Object, e As FileSystemEventArgs)
            If e.ChangeType <> WatcherChangeTypes.Changed Then
                Return
            End If
            Console.WriteLine($"Changed: {e.FullPath}")
        End Sub

        Private Shared Sub OnCreated(sender As Object, e As FileSystemEventArgs)
            Dim value As String = $"Created: {e.FullPath}"
            Console.WriteLine(value)
        End Sub

        Private Shared Sub OnDeleted(sender As Object, e As FileSystemEventArgs)
            Console.WriteLine($"Deleted: {e.FullPath}")
        End Sub

        Private Shared Sub OnRenamed(sender As Object, e As RenamedEventArgs)
            Console.WriteLine($"Renamed:")
            Console.WriteLine($"    Old: {e.OldFullPath}")
            Console.WriteLine($"    New: {e.FullPath}")
        End Sub

        Private Shared Sub OnError(sender As Object, e As ErrorEventArgs)
            PrintException(e.GetException())
        End Sub

        Private Shared Sub PrintException(ex As Exception)
            If ex IsNot Nothing Then
                Console.WriteLine($"Message: {ex.Message}")
                Console.WriteLine("Stacktrace:")
                Console.WriteLine(ex.StackTrace)
                Console.WriteLine()
                PrintException(ex.InnerException)
            End If
        End Sub

    End Class

End Namespace

Remarks

Some common occurrences, such as copying or moving a file or directory, do not correspond directly to an event, but these occurrences do cause events to be raised. When you copy a file or directory, the system raises a Created event in the directory to which the file was copied, if that directory is being watched. If the directory from which you copied was being watched by another instance of FileSystemWatcher, no event would be raised. For example, you create two instances of FileSystemWatcher. FileSystemWatcher1 is set to watch "C:\My Documents", and FileSystemWatcher2 is set to watch "C:\Your Documents". If you copy a file from "My Documents" into "Your Documents", a Created event will be raised by FileSystemWatcher2, but no event is raised for FileSystemWatcher1. Unlike copying, moving a file or directory would raise two events. From the previous example, if you moved a file from "My Documents" to "Your Documents", a Created event would be raised by FileSystemWatcher2 and a Deleted event would be raised by FileSystemWatcher1.

Note

Common file system operations might raise more than one event. For example, when a file is moved from one directory to another, several OnChanged and some OnCreated and OnDeleted events might be raised. Moving a file is a complex operation that consists of multiple simple operations, therefore raising multiple events. Likewise, some applications (for example, antivirus software) might cause additional file system events that are detected by FileSystemWatcher.

Note

The order in which the Created event is raised in relation to the other FileSystemWatcher events may change when the SynchronizingObject property is not null.

The OnCreated event is raised as soon as a file is created. If a file is being copied or transferred into a watched directory, the OnCreated event will be raised immediately, followed by one or more OnChanged events.

Applies to

Product	Versions
.NET	Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

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