简介
iPhone 5s~iPhone 8都可以通过指纹进行解锁,省去了反复输入密码的繁琐程序,这个就是Touch ID指纹识别技术。在iOS 8以后,Apple也开放了Touch ID的API给开发者,因此很多App也引入了这个新的登录方式。Face ID实现过程与Touch ID基本相同,后期也会再做补充
开发应用
- 要实现指纹识别的功能需要引入LocalAuthentication框架
- 首先我们需要判断目前设备是否支持Touch ID功能
func canEvaluatePolicy(_ policy: LAPolicy, error: NSErrorPointer) -> Bool
- LAPolicy有两个值,分别是
deviceOwnerAuthenticationWithBiometrics
和deviceOwnerAuthentication
- deviceOwnerAuthenticationWithBiometrics:用手指指纹去验证,iOS8.0以上可用
- deviceOwnerAuthentication:使用TouchID或者密码验证,默认是错误三次指纹或者锁定后,弹出输入密码界面iOS 9.0以上可用
- 开始指纹验证
func evaluatePolicy(_ policy: LAPolicy, localizedReason: String, reply: @escaping (Bool, Error?) -> Void)
主要代码
func evaluate(reason: String, completed: @escaping (_ isSuccess: Bool)->()) {
//记录是否开启Touch ID
var canTouchID = true
canTouchID = content.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)
guard canTouchID else {
completed(false)
return
}
//本地认证上下文联系对象,每次使用Touch ID功能都要重新初始化
content = nil
content = LAContext()
guard let content = content else { return }
//调起Touch ID验证弹框
content.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: “指纹验证登录”) {
(success, error) in
//成功与失败进行相应的操作
if success {
completed(true)
}else {
completed(false)
print("\(error!)")
if let errorCode = LAError.Code(rawValue: (error! as NSError).code) {
switch errorCode
//对应errorCode的相应操作
……
}
}
}
}
localizedReason:用于设置提示语,表示为什么要使用Touch ID
常见erro描述
- 在模拟器上运行结果
Error Domain=com.apple.LocalAuthentication Code=-1000 "Simulator is not supported."
UserInfo=0x7ffe604b0790 {NSLocalizedDescription=Simulator is not supported.
- 在有TouchID 的功能下,没有设置TouchID的运行结果
Error Domain=com.apple.LocalAuthentication Code=-7 "No fingers are enrolled with Touch ID."
UserInfo=0x170075fc0 {NSLocalizedDescription=No fingers are enrolled with Touch ID.
- 连续三次指纹识别错误
Error Domain=com.apple.LocalAuthentication Code=-1 "Aplication retry limit exceeded."
UserInfo=0x1740797c0 {NSLocalizedDescription=Aplication retry limit exceeded.}
- 用户在Touch ID对话框中点击了取消按钮
Error Domain=com.apple.LocalAuthentication Code=-2 "Canceled by user."
UserInfo=0x17006c780 {NSLocalizedDescription=Canceled by user.
- Touch ID三次校验失败
Error Domain=com.apple.LocalAuthentication Code=-1 "Application retry limit exceeded."
UserInfo={NSLocalizedDescription=Application retry limit exceeded.}
- Touch ID多次校验失败
Error Domain=com.apple.LocalAuthentication Code=-8 "Biometry is locked out."
UserInfo={NSLocalizedDescription=Biometry is locked out.
参考文章
https://www.jianshu.com/p/aef5a506311b
https://juejin.im/entry/59795ee95188253e000a74c3
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