• Xcode 8.1 or later
• iOS 8.0 or later

引入指紋解鎖必須的頭文件

#import <LocalAuthentication/LocalAuthentication.h>

判斷設備是否支持TouchID

- (BOOL)canEvaluatePolicy:(LAPolicy)policy error:(NSError * __autoreleasing *)error __attribute__((swift_error(none)));

彈出框出來驗證TouchID,Block返回成功和失敗的回調

- (void)evaluatePolicy:(LAPolicy)policy localizedReason:(NSString *)localizedReason reply:(void(^)(BOOL success, NSError * __nullable error))reply;

驗證的例子

//初始化上下文對象
    LAContext* context = [[LAContext alloc] init];
//錯誤對象
    NSError* error = nil;
    NSString* result = @"Authentication is needed to access your notes.";
//首先使用canEvaluatePolicy 判斷設備支持狀態
    if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
        //支持指紋驗證
        [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:result reply:^(BOOL success, NSError *error) {
            if (success) {
                //驗證成功，主線程處理UI
            }
            else
            {
                NSLog(@"%@",error.localizedDescription);
                switch (error.code) {
                    case LAErrorSystemCancel:
                    {
                        NSLog(@"Authentication was cancelled by the system");
                        //切換到其他APP，系統取消驗證Touch ID
                        break;
                    }
                    case LAErrorUserCancel:
                    {
                        NSLog(@"Authentication was cancelled by the user");
                        //用戶取消驗證Touch ID
                        break;
                    }
                    case LAErrorUserFallback:
                    {
                        NSLog(@"User selected to enter custom password");
                        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                            //用戶選擇其他驗證方式，切換主線程處理
                        }];
                        break;
                    }
                    default:
                    {
                        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                            //其他情況，切換主線程處理
                        }];
                        break;
                    }
                }
            }
        }];
    }
    else
    {
        //不支持指紋識別，LOG出錯誤詳情
        
        switch (error.code) {
            case LAErrorTouchIDNotEnrolled:
            {
                NSLog(@"TouchID is not enrolled");
                break;
            }
            case LAErrorPasscodeNotSet:
            {
                NSLog(@"A passcode has not been set");
                break;
            }
            default:
            {
                NSLog(@"TouchID not available");
                break;
            }
        }
        
        NSLog(@"%@",error.localizedDescription);
    }

幾種返回的錯誤的枚舉值

typedef NS_ENUM(NSInteger, LAError)
 { 
     //授權失敗  
     LAErrorAuthenticationFailed = kLAErrorAuthenticationFailed, 

     //用戶取消Touch ID授權  
     LAErrorUserCancel = kLAErrorUserCancel, 

     //用戶選擇輸入密碼  
     LAErrorUserFallback = kLAErrorUserFallback, 

     //系統取消授權(例如其他APP切入)  
     LAErrorSystemCancel = kLAErrorSystemCancel, 

     //系統未設置密碼  
     LAErrorPasscodeNotSet =kLAErrorPasscodeNotSet, 

     //設備Touch ID不可用，例如未打開  
     LAErrorTouchIDNotAvailable = kLAErrorTouchIDNotAvailable, 

     //設備Touch ID不可用，用戶未錄入  
     LAErrorTouchIDNotEnrolled = kLAErrorTouchIDNotEnrolled, } NS_ENUM_AVAILABLE(10_10, 8_0);
}

Touch ID的簡單例子：https://github.com/smanx/Touch-ID-Demo