Class FileWatcher

Namespace

Cuemon.Runtime

Assembly

Cuemon.Core.dll

Provides a watcher implementation designed to monitor and signal changes applied to a file by raising the Changed event.

public class FileWatcher : Watcher, IWatcher, IDisposable

Inheritance

object

Disposable

Watcher

FileWatcher

Implements

IWatcher

IDisposable

Inherited Members

Watcher.Changed

Watcher.UtcLastModified

Watcher.UtcLastSignaled

Watcher.DueTime

Watcher.Period

Watcher.DueTimeOnChanged

Watcher.StartMonitoring()

Watcher.ChangeSignaling(TimeSpan)

Watcher.ChangeSignaling(TimeSpan, TimeSpan)

Watcher.OnDisposeManagedResources()

Watcher.OnDisposeUnmanagedResources()

Watcher.SetUtcLastModified(DateTime)

Watcher.HandleSignaling()

Watcher.OnChangedRaised()

Watcher.OnChangedRaised(WatcherEventArgs)

Disposable.Disposed

Disposable.Dispose()

Disposable.Dispose(bool)

Examples

The following example shows how to start a file watcher, observe change notifications, and pause signaling again.

using System;
using System.IO;
using System.Threading;
using Cuemon.Runtime;

namespace MyApp.Examples;

public static class FileWatcherExample
{
    public static void Demonstrate()
    {
        string filePath = Path.Combine(Environment.CurrentDirectory, "health.txt");
        File.WriteAllText(filePath, "ready");

        using var watcher = new FileWatcher(filePath, readFile: true, options =>
        {
            options.DueTime = TimeSpan.Zero;
            options.Period = TimeSpan.FromSeconds(5);
            options.DueTimeOnChanged = TimeSpan.FromMilliseconds(250);
        });

        watcher.Changed += static (_, e) => Console.WriteLine($"{e.UtcLastModified:O} ({e.Delayed.TotalMilliseconds} ms)");
        watcher.StartMonitoring();

        Console.WriteLine(watcher.Path);
        Console.WriteLine(watcher.ReadFile);
        Console.WriteLine(watcher.UtcCreated.ToString("O"));

        watcher.ChangeSignaling(Timeout.InfiniteTimeSpan);
    }
}

Constructors

FileWatcher(string, bool, Action<WatcherOptions>)

Initializes a new instance of the FileWatcher class.

public FileWatcher(string path, bool readFile = false, Action<WatcherOptions> setup = null)

Parameters

path string

The file to monitor, in standard or Universal Naming Convention (UNC) notation.

readFile bool

if set to true the file specified in path will be opened and a checksum will be computed using CyclicRedundancyCheck64 algorithm.

setup Action<WatcherOptions>

The WatcherOptions which may be configured.

Properties

Checksum

Gets the checksum that is associated with the file specified in Path.

public string Checksum { get; }

Property Value

string

The checksum that is associated with the file specified in Path.

Remarks

If ReadFile is false this property will remain null.

Path

Gets the path of the file to watch.

public string Path { get; }

Property Value

string

The path to monitor.

ReadFile

Gets a value indicating whether the file specified in Path will be opened, read and assign the computed value to Checksum.

public bool ReadFile { get; }

Property Value

bool

true if the file specified in Path will be opened, read and assign the computed value to Checksum; otherwise, false.

UtcCreated

Gets the time, in Coordinated Universal Time (UTC), when this instance was created.

public DateTime UtcCreated { get; }

Property Value

DateTime

The time, in Coordinated Universal Time (UTC), when this instance was created.

Methods

HandleSignalingAsync()

Handles the signaling of this FileWatcher.

protected override Task HandleSignalingAsync()

Returns

Task

See Also

Watcher