Single Instance Control Component

using System;
using System.Diagnostics;
using System.ComponentModel;
namespace InstConLib
{
/// <summary>
/// InstanceControlLib Class controls the instance .
/// </summary>
public class InstanceControl: Component
{
private string stProcName=null;
//constructor which holds the application name
public InstanceControl(string ProcName)
{
stProcName=ProcName;
}
public bool IsAnyInstanceExist()
{
//process class GetProcessesByName() checks for particular
//process is currently running and returns array of processes
//with that name
Process[] processes = Process.GetProcessesByName(stProcName);
if(processes.Length != 1)
return false; //false no instance exist
else
return true; //true mean existance exist
}
} //end of class
} // end of namespace

Compile the above as component library to produce .dll file then one can call this component in different clients like WinForms, WebFroms or Console applications.I have used simple console application to use this component.

The client program calls the InstanceControl component and uses its method. In this example I used to instance of component one which will check for the process that is not running and other which checks for the process which is running in the system.

Following is the code snippet of the client application

//InstClient.cs

using System;
using InstConLib;
public class InstClient
{
public static void Main()
{

//First Object which looks for testApp.exe process
//remember its not neccessary to give extention of process
InstConLib.InstanceControl in1 = new InstConLib.InstanceControl("testApp");
if(in1.IsAnyInstanceExist())
Console.WriteLine("Alreading one instance is running");
else
Console.WriteLine("No Instance running");
//Second Object which looks for Explorer.exe process

//remember its not neccessary to give extention of process
InstConLib.InstanceControl in2 = new InstConLib.InstanceControl("Explorer");
if(in2.IsAnyInstanceExist())
Console.WriteLine("Alreading one instance is running");
else
Console.WriteLine("No Instance running");
}
}

OUTPUT:

D:\vstudio>InstClient
No Instance running
Alreading one instance is running

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