Call a static method of a custom class

Question

I am writing a powershell script which use my own DLL in it:

[System.Reflection.Assembly]::LoadFile("E:\Group.School.dll")

I want to access a static method in Student class. That static method has been overloaded.

Class Student
{        
    public static sting GetData(string id)
    {
        ....
    }

    public static sting GetData(string fName, string lName)
    {
        ....
    }        
}

From PowerShell I am going to access the first method like below:

$data = [Group.School.Student]::GetData
$data.Invoke("myId") 

This gives me an exception saying

Exception calling "Invoke" with "1" argument(s): "Exception calling "GetData" with "1" argument(s): "Object reference not set to an instance of an object.""

Answer 1

The original code contains a few typos (e.g. Class, sting) and a mistake - the class has to be public.

Here is the corrected code which works without errors:

# the corrected code added inline (might be in a DLL, as well):
Add-Type @'
public class Student
{
    public static string GetData(string id)
    {
        return "data1";
    }

    public static string GetData(string fName, string lName)
    {
        return "data2";
    }
}
'@

# call the static method:
[Student]::GetData('myId')

Answer 2

Try:

[Group.School.Student]::GetData('myId')