Generic usage is not clear in one program

Tridip Bhattacharjee

see this class code

public class ShipperFactory
{
private static TShip Create()
where TShip : IShip, // interface contract constraint
new() // public parameter-less constructor constraint
{
return new TShip();
}

    public static readonly IDictionary\> Creators =
        new Dictionary\>()
    {
        { Shipper.UPS, () => Create() },
        { Shipper.FedEx, () => Create() },
        { Shipper.Purolator, () => Create() }
    };

    public static IShip CreateInstance(Shipper enumModuleName)
    {
        return Creators\[enumModuleName\]();
    }
}

specially the below code is not clear where

public static readonly IDictionary> Creators =
new Dictionary>()
{
{ Shipper.UPS, () => Create() },
{ Shipper.FedEx, () => Create() },
{ Shipper.Purolator, () => Create() }
};

see this line whose meaning is not clea. what is the meaning of Func ? new Dictionary>() Dictionary usage is not clear. help me to understand the code of Dictionary and as well as ShipperFactory class. it is required to use both interface and abstract class ? is it not redundant here ? here giving the full code which show how i am using ShipperFactory class calling like this way --------------------------

private void btnUPS_Click(object sender, EventArgs e)
{
ShipperFactory.CreateInstance(Shipper.UPS).Ship();
}

    private void btnFedEx\_Click(object sender, EventArgs e)
    {
        ShipperFactory.CreateInstance(Shipper.FedEx).Ship();
    }

    private void btnPurolator\_Click(object sender, EventArgs e)
    {
        ShipperFactory.CreateInstance(Shipper.Purolator).Ship();
    }

public enum Shipper
{
    UPS,
    FedEx,
    Purolator
}

public interface IShip
{
    void Ship();
}

public abstract class ShipperBase : IShip
{
    //Etc
    public abstract void Ship();

}

public class ShipperUPS : ShipperBase
{
    public override void Ship()
    {
        //-- cod

Lost User

The dictionary contains a "key" for each carrier and a "function" (value) that is used to create an instance of that carrier. Over-engineered and pointless indirection (IMO). (A "carrier" class and a "carrier id / ident" would be simpler).

"(I) am amazed to see myself here rather than there ... now rather than then". ― Blaise Pascal

OriginalGriff

DNFTHV * :laugh: * Do not feed the Help Vampire

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

Lost User

It's actually passive aggression :cool:

"(I) am amazed to see myself here rather than there ... now rather than then". ― Blaise Pascal

OriginalGriff

:laugh: Some of these don't deserve "passive" - they just don't want to think for themselves...

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

Lost User

Tridip Bhattacharjee wrote:

looking for help

Try asking the person who wrote the code.