How to create a single instance of class

Rafnas T P

10y1.1k

How to make single instance of class and how to use in all the modules

11 Replies

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Mageshwaran R7y ago
Hi,
public sealed class Singleton
{
     public static readonly Singleton instance = new Singleton();
     private Singleton() {}
}
0
Vinay Singh10y ago
Hi
Please report it to the write of the article :-) :-)
0
ketan borsdiya10y ago
Hi Rafnas,
I dont think so NameOfClass obj=new NameOfClass(); is to possible create global instance.
for single instance of class you might have to use singleton pattern.

Prefer below code

public class Test
{
Private Test()
{
}
static Test _testInstance;
public static Test TestInstance
{
get
{
if _testInstance;== null)
{
lock (_lock)
{
if _testInstance;== null)
{
_testInstance;= new Test();
}
}
}
return _testInstance;
}
}

Public int Add(int a, int b)
{
return a+b;
}

//Add here Methods or Members whatever you want required
}

Now you have to access Add method in your project write below sentence

Test.TestInstance.Add(10,20);
0
ketan borsdiya10y ago
Hi Vinay,
as per you provide details about static class and singleton class is wrong.
Because static class has only one static constructor and also I think we are not creating object of singleton class bacause singleton class means object itself.
I suggest code to Rafnas is singleton class pattern singleton class has private constructor.
So, we are not able to create object of that class.
0
Vinay Singh10y ago
Check the link
http://csharpindepth.com/Articles/General/Singleton.aspx
https://msdn.microsoft.com/en-us/library/ff650316.aspx
http://www.dotnetperls.com/singleton
0
Vinay Singh10y ago
Hi
Yes i am agree with you. but it's not the way to use singleton.

0
Rafnas T P10y ago
I wanted to create one instance of class like for ex,
NameOfClass obj=new NameOfClass();
and then I want this obj to use it in every window or pages, can you tell me how it is possible
0
ketan borsdiya10y ago
Hi Vinay,
I know, we are not able to create instance of static class. But We are creating Instance property of Normal class so its allow the static. I am not sayin to put static keyword before class name.
I have already used it and its working fine.
0
Vinay Singh10y ago
Hi
Ketan There is huge difference between Static class and singleton have a look of the difference.
Static Class:
You cannot create the instance of static class.

Loaded automatically by the .NET Framework common language runtime (CLR) when the program or namespace containing the class is loaded.

Static Class cannot have constructor.

We cannot pass the static class to method.

We cannot inherit Static class to another Static class in C#.

Singleton:
You can create one instance of the object and reuse it.

Singleton instance is created for the first time when the user requested.

Singleton class can have constructor.

You can create the object of singleton class and pass it to method.

Singleton class does not say any restriction of Inheritance.

We can dispose the objects of a singleton class but not of static class.
For detail check the link
http://www.dotnetperls.com/singleton-static
http://www.c-sharpcorner.com/UploadFile/akkiraju/singleton-vs-static-classes/
0
ketan borsdiya10y ago
Hi Rafnas,
Write below property in
static _test;
public static Test
{
get
{
if _test;== null)
{
lock (_lock)
{
if _test;== null)
{
_test;= new ();
}
}
}
return _test;
}
}
Now you may use Test as class instance in your project like
.Test.
0
Vinay Singh10y ago
Hi
By using singleton pattern of of c#. you can create single instance of class
http://csharpindepth.com/Articles/General/Singleton.aspx
https://msdn.microsoft.com/en-us/library/ff650316.aspx
http://www.dotnetperls.com/singleton
0