Swift
Swift
PC/SC Wait for Smart Card Status Change (Inserted, Removed from Reader, etc.)
See more SCard Examples
Demonstrates how to synchronously wait for a status change, such as for a smart card to be inserted into a reader, or removed from a reader.Note: This functionality was introduced in Chilkat v9.5.0.87.
Chilkat Swift Downloads
func chilkatTest() {
var success: Bool = false
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
let scard = CkoSCard()!
// First establish a context to the PC/SC Resource Manager
success = scard.establishContext(scope: "user")
if success == false {
print("\(scard.lastErrorText!)")
return
}
// First we'll examine the state of all connected readers to see which have smartcards already inserted..
// Get JSON containing information about the smartcards currently inserted into readers.
// This also includes information about USB security tokens.
let json = CkoJsonObject()!
success = scard.findSmartcards(json: json)
if success == false {
print("\(scard.lastErrorText!)")
return
}
// When writing this example, I have 3 smart card readers plugged into my system.
// One of them has a smart card inserted.
// Here's the JSON returned by FindSmartcards...
// {
// "reader": [
// {
// "name": "Alcor Micro USB Smart Card Reader 0",
// "state": "empty"
// },
// {
// "name": "Generic Smart Card Reader Interface 0",
// "state": "present",
// "vendorName": "Generic",
// "serialNumber": "3230303730383138303030303030303030",
// "systemName": "Generic Smart Card Reader Interface 0",
// "card": {
// "atr": "3BFC180000813180459067464A00641606F2727E00E0",
// "windows": {
// "miniDriver": "tagliov70px.dll",
// "cryptoProvider": "Microsoft Base Smart Card Crypto Provider",
// "keyStorageProvider": "Microsoft Smart Card Key Storage Provider"
// }
// }
// },
// {
// "name": "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0",
// "state": "empty"
// }
// ]
// }
json.emitCompact = false
print("\(json.emit()!)")
print(" ")
// We can iterate over the JSON to find the readers with a smart card already inserted..
var name: String?
let sbState = CkoStringBuilder()!
var i: Int = 0
var count_i: Int = json.size(ofArray: "reader").intValue
while i < count_i {
json.i = i
name = json.string(of: "reader[i].name")
sbState.clear()
json.string(ofSb: "reader[i].state", sb: sbState)
if sbState.contains(str: "present", caseSensitive: true) == true {
print("\(name!) has a smart card inserted.")
}
else {
print("\(name!) does not have a smart card inserted.")
}
i = i + 1
}
print(" ")
// Now let's begin the code to wait for a change (where a smart card gets inserted or removed)
// Get the list of all readers.
let stReaders = CkoStringTable()!
success = scard.listReaders(st: stReaders)
if success == false {
print("\(scard.lastErrorText!)")
return
}
// Show the reader names..
var numReaders: Int = stReaders.count.intValue
i = 0
while i < numReaders {
print("\(i): \(stReaders.string(at: i)!)")
i = i + 1
}
// Sample output from the above loop.
// 0: Alcor Micro USB Smart Card Reader 0
// 1: Generic Smart Card Reader Interface 0
// 2: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
//
// Synchronously wait 30 seconds for a card to be inserted or removed from any of the above readers.
let json2 = CkoJsonObject()!
success = scard.getStatusChange(maxWaitMs: 30000, stReaderNames: stReaders, json: json2)
if success == false {
print("\(scard.lastErrorText!)")
return
}
print(" ")
// Let's see what happened...
json2.emitCompact = false
print("\(json2.emit()!)")
print(" ")
// This is what json2 contains.
// A card was inserted into the reader named "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0"
// The "numChanged" indicates that one reader's status changed.
// The "changed":true indicates the reader that changed. The state is now "present".
// {
// "numChanged": 1,
// "reader": [
// {
// "name": "Alcor Micro USB Smart Card Reader 0",
// "changed": false,
// "state": "empty"
// },
// {
// "name": "Generic Smart Card Reader Interface 0",
// "changed": false,
// "state": "present",
// "atr": "3BFC180000813180459067464A00641606F2727E00E0"
// },
// {
// "name": "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0",
// "changed": true,
// "state": "present",
// "atr": "3BDF96FF8131FE455A018048494443313158587300011B09"
// }
// ]
// }
// Find the reader that changed...
var changed: Bool
var state: String?
var atr: String?
var numChanged: Int = json2.int(of: "numChanged").intValue
print("number of readers with a changed state: \(numChanged)")
i = 0
count_i = json2.size(ofArray: "reader").intValue
while i < count_i {
json2.i = i
changed = json2.bool(of: "reader[i].changed")
if changed == true {
name = json2.string(of: "reader[i].name")
state = json2.string(of: "reader[i].state")
print("Changed: ")
print(" reader name: \(name!)")
print(" new state: \(state!)")
// If a card is now in this reader, we should have the ATR of the card..
if json2.hasMember(jsonPath: "reader[i].atr") == true {
atr = json2.string(of: "reader[i].atr")
print(" ATR of card inserted into this reader: \(atr!)")
}
}
i = i + 1
}
// The output from the above loop:
// number of readers with a changed state: 1
// Changed:
// reader name: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
// new state: present
// ATR of card inserted into this reader: 3BDF96FF8131FE455A018048494443313158587300011B09
// Applications should always release the context when finished.
success = scard.releaseContext()
if success == false {
print("\(scard.lastErrorText!)")
}
}