Create object instance of a class from its name in string variable

Question

I don't know whether this is possible or not, but I would like to know if it is and, if so, how it works. So here is my question:

I have 2-3 custom model classes of my own. For example, Customer, Employee and Product. I also have a class name in a string. Based on the class name, I want to create an instance and return it to a view. How can I achieve this?

I know that one option is an if/else statement, but I would like a better, dynamic way.

What you are looking for is reflection, but as a general rule, if you are using reflection, you might be doing something wrong (there are cases where you need reflection, but it's not common). — Mike C., Mar 16 '13 at 13:29

Display Name · Accepted Answer · 2015-10-16T16:56:54.700

42

Having the class name in string is not enough to be able to create its instance. As a matter of fact you will need full namespace including class name to create an object.

Assuming you have the following:

string className = "MyClass";
string namespaceName = "MyNamespace.MyInternalNamespace";

Than you you can create an instance of that class, the object of class MyNamespace.MyInternalNamespace.MyClass using either of the following techniques:

var myObj = Activator.CreateInstance(namespaceName, className);

or this:

var myObj = Activator.CreateInstance(Type.GetType(namespaceName + "." + className));

Hope this helps, please let me know if not.

edited Oct 16 '15 at 16:56

answered Mar 16 '13 at 18:17

Display Name

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I have class name in a string. so basically I dnt knw the class type. Then how could I create object of particular class. In "MyClass myObj = " I have to give MyClass. bt there can be any class. – Dhwani Mar 18 '13 at 05:25
I did exactly what you trying to do. As I have mentioned Besides the class name you need the namespace (as a string). Having them both, you can create instance of the object of that class the way I showed. I'll edit the answer to clarify. Thanks for aksing – Display Name Mar 18 '13 at 12:33
4

Shouldn't that last code read: "var myObj = Activator.CreateInstance(Type.GetType(namespaceName + "." + className));" (missing dot?) – JCCyC Mar 10 '15 at 20:35
hey plz help me i have same problem but this solution doesn't work for me see [Here please](http://stackoverflow.com/questions/38596936/i-have-a-helper-that-use-activator-createinstancesitaad-models-table-but-n) – SdSaati Jul 26 '16 at 18:21

score 9 · Answer 2 · answered Sep 25 '13 at 12:58

    string frmName = "frmCustomer";
    //WorldCarUI. is the namespace of the form
    Type CAType = Type.GetType("WorldCarUI." + frmName );
    var myObj = Activator.CreateInstance(CAType);
    Form nextForm2 = (Form)myObj;
    nextForm2.Show();

this does works..

Regards Avi

score 2 · Answer 3 · answered Mar 16 '13 at 13:40

the easiest way is to use Activator. Pass class name to GetType and Create new instance.

ClassInstance s1 = (ClassInstance)Activator.CreateInstance(Type.GetType("App.ClassInstance"));

public class ClassInstance
{
    public string StringData { get; set; }
}

Regards, Nik

score 0 · Answer 4 · answered Aug 06 '18 at 10:24

Activator class does this job in .net and this technique is very usefull for dependency injection kind of scenarios.

string NameSpace = "ProjectName.YourNameSpace";
string ProbeClass = "CLassName";

ObjectHandle ProberHandle = Activator.CreateInstance(NameSpace, ProbeClass) as ObjectHandle;
ClassName Prober = ProberHandle.Unwrap() as ClassName;

Ensure that you unwrap before type casting otherwise it will give conversion error.

Create object instance of a class from its name in string variable

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