ktsu.SingleAppInstance 1.3.46

Prefix Reserved

dotnet add package ktsu.SingleAppInstance --version 1.3.46

NuGet\Install-Package ktsu.SingleAppInstance -Version 1.3.46

This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.

<PackageReference Include="ktsu.SingleAppInstance" Version="1.3.46" />

For projects that support PackageReference, copy this XML node into the project file to reference the package.

<PackageVersion Include="ktsu.SingleAppInstance" Version="1.3.46" />
                    

                            Directory.Packages.props

<PackageReference Include="ktsu.SingleAppInstance" />
                    

                            Project file

For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.

paket add ktsu.SingleAppInstance --version 1.3.46

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

#r "nuget: ktsu.SingleAppInstance, 1.3.46"

#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.

#:package ktsu.SingleAppInstance@1.3.46

#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.

#addin nuget:?package=ktsu.SingleAppInstance&version=1.3.46
                    

                            Install as a Cake Addin

#tool nuget:?package=ktsu.SingleAppInstance&version=1.3.46
                    

                            Install as a Cake Tool

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

ktsu.SingleAppInstance

A .NET library that ensures only one instance of your application is running at a time.

Introduction

ktsu.SingleAppInstance is a lightweight .NET library that provides a robust mechanism to ensure only one instance of an application is running at a time. It uses a JSON-serialized PID file with multi-attribute process verification to accurately detect running instances, making it ideal for desktop applications, services, or any software that requires instance exclusivity to prevent resource conflicts or maintain data integrity.

Features

Single Instance Enforcement: Prevents multiple copies of your application from running simultaneously
Enhanced Process Identification: Verifies running instances using multiple attributes (PID, process name, start time, executable path) for accurate detection
Race Condition Handling: Includes a built-in 1-second delay to safely detect simultaneous startup attempts
PID File Management: Stores process information as JSON in the application data directory
Backward Compatibility: Gracefully handles legacy PID files that stored only a plain integer PID
Simple API: Two methods — ExitIfAlreadyRunning() for automatic exit and ShouldLaunch() for custom logic
Multi-Target Support: Works across .NET 10.0 through .NET 5.0, .NET Standard 2.0/2.1

Installation

Package Manager Console

Install-Package ktsu.SingleAppInstance

.NET CLI

dotnet add package ktsu.SingleAppInstance

Package Reference

<PackageReference Include="ktsu.SingleAppInstance" Version="x.y.z" />

Usage Examples

Basic Example

The simplest way to use SingleAppInstance is to call ExitIfAlreadyRunning at the start of your application. If another instance is detected, the process exits automatically:

using ktsu.SingleAppInstance;

class Program
{
    static void Main(string[] args)
    {
        SingleAppInstance.ExitIfAlreadyRunning();

        // Your application code here
        Console.WriteLine("Application is running.");
    }
}

Custom Launch Logic

If you prefer to handle the duplicate-instance case yourself, use ShouldLaunch() which returns a boolean:

using ktsu.SingleAppInstance;

class Program
{
    static void Main(string[] args)
    {
        if (SingleAppInstance.ShouldLaunch())
        {
            // Your application code here
            Console.WriteLine("Application is running.");
        }
        else
        {
            Console.WriteLine("Another instance is already running.");
        }
    }
}

WPF Application Integration

using System.Windows;
using ktsu.SingleAppInstance;

namespace MyWpfApp
{
    public partial class App : Application
    {
        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            if (!SingleAppInstance.ShouldLaunch())
            {
                MessageBox.Show("Application is already running.");
                Shutdown();
                return;
            }

            MainWindow = new MainWindow();
            MainWindow.Show();
        }
    }
}

API Reference

`SingleAppInstance`

A static class that provides single-instance enforcement for applications. Uses a PID file stored in the application data directory to track running instances.

Methods

Name	Return Type	Description
`ExitIfAlreadyRunning()`	`void`	Checks if another instance is running and calls `Environment.Exit(0)` if so
`ShouldLaunch()`	`bool`	Writes a PID file, waits 1 second for race condition detection, and returns `true` if safe to proceed

Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

License

This project is licensed under the MIT License. See the LICENSE.md file for details.

Product	Compatible and additional computed target framework versions.
.NET	net5.0 is compatible. net5.0-windows was computed. net6.0 is compatible. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 is compatible. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 is compatible. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. net9.0 is compatible. net9.0-android was computed. net9.0-browser was computed. net9.0-ios was computed. net9.0-maccatalyst was computed. net9.0-macos was computed. net9.0-tvos was computed. net9.0-windows was computed. net10.0 is compatible. net10.0-android was computed. net10.0-browser was computed. net10.0-ios was computed. net10.0-maccatalyst was computed. net10.0-macos was computed. net10.0-tvos was computed. net10.0-windows was computed.
.NET Core	netcoreapp2.0 was computed. netcoreapp2.1 was computed. netcoreapp2.2 was computed. netcoreapp3.0 was computed. netcoreapp3.1 was computed.
.NET Standard	netstandard2.0 is compatible. netstandard2.1 is compatible.
.NET Framework	net461 was computed. net462 was computed. net463 was computed. net47 was computed. net471 was computed. net472 was computed. net48 was computed. net481 was computed.
MonoAndroid	monoandroid was computed.
MonoMac	monomac was computed.
MonoTouch	monotouch was computed.
Tizen	tizen40 was computed. tizen60 was computed.
Xamarin.iOS	xamarinios was computed.
Xamarin.Mac	xamarinmac was computed.
Xamarin.TVOS	xamarintvos was computed.
Xamarin.WatchOS	xamarinwatchos was computed.

Compatible target framework(s)

Included target framework(s) (in package)

Learn more about Target Frameworks and .NET Standard.

.NETStandard 2.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Memory (>= 4.6.3)
- System.Text.Json (>= 10.0.11)
- System.Threading.Tasks.Extensions (>= 4.6.3)
.NETStandard 2.1
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Text.Json (>= 10.0.11)
net10.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
net5.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Text.Json (>= 10.0.11)
net6.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Text.Json (>= 10.0.11)
net7.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Text.Json (>= 10.0.11)
net8.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Text.Json (>= 10.0.11)
net9.0
- ktsu.AppDataStorage (>= 1.16.37)
- ktsu.Semantics.Paths (>= 3.0.1)
- ktsu.Semantics.Strings (>= 3.0.1)
- System.Text.Json (>= 10.0.11)

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version	Downloads	Last Updated
1.3.46	50	8/19/2026
1.3.45	54	8/18/2026
1.3.44	72	8/17/2026
1.3.43	183	7/8/2026
1.3.42	125	7/7/2026
1.3.41	126	7/6/2026
1.3.40	124	7/3/2026
1.3.39	137	7/2/2026
1.3.38	120	7/1/2026
1.3.37	130	6/30/2026
1.3.36	131	6/29/2026
1.3.35	129	6/28/2026
1.3.34	125	6/28/2026
1.3.33	180	6/15/2026
1.3.32	144	6/12/2026
1.3.31	148	6/9/2026
1.3.30	146	6/8/2026
1.3.29	150	6/5/2026
1.3.28	167	6/3/2026
1.3.27	349	5/25/2026

## v1.3.46 (patch)

Changes since v1.3.45:

- chore: store icon.png in LFS as .gitattributes declares ([@matt-edmondson](https://github.com/matt-edmondson))
- docs: scope build badge to the default branch ([@matt-edmondson](https://github.com/matt-edmondson))

ktsu.SingleAppInstance 1.3.46

ktsu.SingleAppInstance

Introduction

Features

Installation

Package Manager Console

.NET CLI

Package Reference

Usage Examples

Basic Example

Custom Launch Logic

WPF Application Integration

API Reference

SingleAppInstance

Methods

Contributing

License

.NETStandard 2.0

.NETStandard 2.1

net10.0

net5.0

net6.0

net7.0

net8.0

net9.0

NuGet packages

GitHub repositories

`SingleAppInstance`