How to invoke c# function from another project without adding reference?

Question

There is a C#.net library project whose DLL name is customer.dll. It has a class name customer with a function name show(). I want to call this function from another project but don't want to add the reference to the caller project. Can this be done? Is there any C#.net class that can achieve this?

you can check how to use reflection in c#. assembly load and access the Method create a instances and access the method — umasankar, Jul 05 '17 at 06:22
Possible duplicate of [How to use reflection to call method by name](https://stackoverflow.com/questions/3110280/how-to-use-reflection-to-call-method-by-name) — garfbradaz, Jul 05 '17 at 06:40

Alexander Higgins · Accepted Answer · 2022-08-27T01:14:20.803

8

Yes, you can load assemblies dynamically using Assembly.LoadFile

Assembly.LoadFile("c:\\somefolder\\Path\\To\\Code.dll");

You are then going to need to use Reflection to get the methodinfo for the function you want to invoke or use the Dynamic keyword to invoke it.

var externalDll = Assembly.LoadFile("c:\\somefolder\\Customer.dll");
var externalTypeByName = externalDll.GetType("CustomerClassNamespace.Customer");

// If you don't know the full type name, use linq
var externalType = externalDll.ExportedTypes.FirstOrDefault(x => x.Name == "Customer");

//if the method is not static create an instance.
//using dynamic 
dynamic dynamicInstance = Activator.CreateInstance(externalType);
var dynamicResult = dynamicInstance.show();

// or using reflection
var reflectionInstance = Activator.CreateInstance(externalType);
var methodInfo = theType.GetMethod("show");
var result = methodInfo.Invoke(reflectionInstance, null);

// Again you could also use LINQ to get the method
var methodLINQ = externalType.GetMethods().FirstOrDefault(x => x.Name == "show");
var resultLINQ = methodLINQ.Invoke(reflectionInstance, null);

edited Aug 27 '22 at 01:14

answered Jul 05 '17 at 06:26

Alexander Higgins

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Thank you.But What should i write to achieve this .Please Give me some link then i can easily follow – Vaibhav Srivastava Jul 05 '17 at 06:31
Confused. I just showed you how to load the DLL and invoke the method. You simply need to change the path to the DLL and TypeName parameters. If you need further documentation Google `Assembly.LoadFile` and check out the reference documents on MSDN. – Alexander Higgins Jul 05 '17 at 06:36
Oh Great. Thank You so much You saved my time – Vaibhav Srivastava Jul 05 '17 at 06:52
One more thing i am getting error in theType and method. – Vaibhav Srivastava Jul 05 '17 at 06:54
What error? You can use LINQ to find the type `var externalType = externalDll.ExportedTypes.FirstOrDefault(x => x.Name == "Customer");` Same for the method – Alexander Higgins Jul 05 '17 at 07:02
Great!! Thank You – Vaibhav Srivastava Jul 05 '17 at 07:06
I am getting Exception->Absolute path information is required. Assembly.LoadFile() – Vaibhav Srivastava Jul 05 '17 at 07:27
The put an absolute path in there. "c:\\somefolder\customer.dll" – Alexander Higgins Jul 05 '17 at 07:33
But the problem is it can be change and my file extension is .exe not .dll . – Vaibhav Srivastava Jul 05 '17 at 07:37
So how can i do this – Vaibhav Srivastava Jul 05 '17 at 07:38
Some exe's are .net modules and can be loaded the same way. Your question said you had `customer.dll` Many times exe's have dll's they reference. If not you'll have to ask for a DLL. – Alexander Higgins Jul 05 '17 at 07:40
Sorry my mistake i saw after build it created exe not dll. – Vaibhav Srivastava Jul 05 '17 at 07:41

How to invoke c# function from another project without adding reference?

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