1.引入指紋解鎖必須的頭文件

#import <LocalAuthentication/LocalAuthentication.h>

2.了解TouchID最主要的兩個方法
這個方法是判斷設(shè)備是否支持TouchID的贤姆。

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

這個是用來驗證TouchID的，會有彈出框出來匙瘪。

- (void)evaluatePolicy:(LAPolicy)policy localizedReason:(NSString*)localizedReason reply:(void(^)(BOOLsuccess,NSError* __nullableerror))reply;

3.首先,新建LAContext對象

//創(chuàng)建LAContextLAContext *context = [LAContextnew];
//這個屬性是設(shè)置指紋輸入失敗之后的彈出框的選項context.localizedFallbackTitle = @"沒有忘記密碼";

4.然后實現(xiàn)回調(diào)方法乌庶，包括成功以及失敗的

NSError *error = nil;
    if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
        NSLog(@"支持指紋識別");
        [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"請按home鍵指紋解鎖" reply:^(BOOL success, NSError * _Nullable error) {
            if (success) {
                NSLog(@"驗證成功 刷新主界面");
            }else{
                NSLog(@"%@",error.localizedDescription);
                switch (error.code) {
                    case LAErrorSystemCancel:
                    {
                        NSLog(@"系統(tǒng)取消授權(quán)怔毛，如其他APP切入");
                        break;
                    }
                    case LAErrorUserCancel:
                    {
                        NSLog(@"用戶取消驗證Touch ID");
                        break;
                    }
                    case LAErrorAuthenticationFailed:
                    {
                        NSLog(@"授權(quán)失敗");
                        break;
                    }
                    case LAErrorPasscodeNotSet:
                    {
                        NSLog(@"系統(tǒng)未設(shè)置密碼");
                        break;
                    }
                    case LAErrorTouchIDNotAvailable:
                    {
                        NSLog(@"設(shè)備Touch ID不可用果元，例如未打開");
                        break;
                    }
                    case LAErrorTouchIDNotEnrolled:
                    {
                        NSLog(@"設(shè)備Touch ID不可用促王，用戶未錄入");
                        break;
                    }
                    case LAErrorUserFallback:
                    {
                        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                            NSLog(@"用戶選擇輸入密碼，切換主線程處理");
                        }];
                        break;
                    }
                    default:
                    {
                        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                            NSLog(@"其他情況而晒，切換主線程處理");
                        }];
                        break;
                    }
                }
            }
        }];
    }else{
        NSLog(@"不支持指紋識別");
        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);
    }