Apple opened up fingerprint recognition technology after iOS8, and encapsulated it into the LocalAuthentication framework, which means that third-party apps are allowed to authenticate through touch ID, and the method of use is extremely simple.
touch ID usage process
1 Import the LocalAuthentication/LocalAuthentication.h framework
2 Make various conditional judgments, and start using if the conditions are met
// 判断设备是否支持touchId
if ([[UIDevice currentDevice].systemVersion floatValue] < 8.0) {
NSLog(@"系统版本太低,无法进行指纹识别");
return;
}
// 创建验证对象的上下文
LAContext *context = [[LAContext alloc]init];
// 判断设备是否允许使用生物识别技术
if (![context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:nil]) {
NSLog(@"指纹识别技术暂不可用");
return;
}
// 如果条件都满足则开始使用指纹识别
// localizedReason 传入使用指纹识别的原因
[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"验证指纹,以便打开程序" reply:^(BOOL success, NSError * _Nullable error) {
// 指纹识别成功
if (success) {
NSLog(@"指纹识别成功");
}
// 指纹识别失败
switch (error.code){
case LAErrorSystemCancel:
// 可能是您将程序切换出去了,所以系统取消了验证
NSLog(@"系统取消了验证");
break;
case LAErrorUserCancel:
NSLog(@"用户取消了验证");
break;
case LAErrorUserFallback:
// 用户选择输入密码,切换到主线程进行后续处理
NSLog(@"用户选择输入密码");
break;
}
}];
The following figure is an example of the pop-up fingerprint recognition pop-up window
. The first touchID is the name of the app, and the "verify fingerprint to open the program" below is the incoming use reason.