nfc-reader: Error SCardListReaders

Card.SCardListReaders(this.hContext, null, null, ref pcchReaders); is returning a 6 for me and I am not sure how to move forward with throubleshooting.

I am in a .NET 4.x environment and I am not getting any compile errors. I have an ACR122 reader that is working with other software.

The code that is generating the error is below: ` public NFCReader NFC;

void Start()
{
    NFCReader NFC = new NFCReader();

    NFC.CardInserted += new NFCReader.CardEventHandler(CardIn);

    NFC.CardEjected += new NFCReader.CardEventHandler(CardOut);

    NFC.Watch(); //public void Watch()
}

public void CardIn() {
    try
    {
        if (NFC.Connect())
        {
            Debug.Log( NFC.ReadBlock("0"));

        }
        else
        {
            //Give error message about connection...
        }
    }
    catch (Exception ex)
    {
        Debug.Log("Exception Should Not Have Ran: " + ex.Message);
    }
}

public void CardOut()
{
    NFC.Disconnect();
}`

About this issue

Original URL
State: open
Created 5 years ago
Comments: 20 (6 by maintainers)

Most upvoted comments

Well, it works in that I no longer receive that particular error.

But I still am not able to read the cards Uid. The watch() function cycles, but there’s never a change in card status. Once I get that working I can make a PR for it.

jonhack on Mar 19, 2020

Good evening to all, after 1 day of tests i tink to have found where is fired the problem. I tink is for how compiled 32bit or 64bit. ### In visual studio if set 32 bit, all its working fine.

Instead if i dont set “Prefer 32-bit” i have same issue of quindo.

My Pc is a 64bit window 10.

I need to work on 64 bit on my application. I can’t set “prefer 32-bit”

I did some research and I found that in 64bit environment I should use IntPtr instead of int in the declaration of some “winscard” dll variables.

h4kbas, quindo any suggestion ?

dbste71 on Jun 10, 2019

Thanks . My project worked with 32bit build.

ezdiatech on Feb 3, 2022

I had the same issue that was being reported above. I came across this post (https://social.msdn.microsoft.com/Forums/ie/en-US/84faa51e-98ee-4289-8e0f-c1408580f30f/winscard-smart-card-dll-32-bit-64-bit-compatibility?forum=windowscompatibility) that mentioned they had to change the hContext from an Int to a Long. That fixed the issue.

jonhack on Mar 19, 2020