#import 

//iOS8.0后才支持指纹识别接口
  if ([UIDevice currentDevice].systemVersion.floatValue < 8.0) {
    return;
  }

- (void)evaluateAuthenticate
{
  //创建LAContext
  LAContext* context = [[LAContext alloc] init];
  NSError* error = nil;
  NSString* result = @"请验证已有指纹";
  //首先使用canEvaluatePolicy 判断设备支持状态
  if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
    //支持指纹验证
    [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:result reply:^(BOOL success, NSError *error) {
      if (success) {
        //验证成功，主线程处理UI
      }
      else
      {
        NSLog(@"%@",error.localizedDescription);
        switch (error.code) {
          case LAErrorSystemCancel:
          {
            //系统取消授权，如其他APP切入
            break;
          }
          case LAErrorUserCancel:
          {
            //用户取消验证Touch ID
            break;
          }
          case LAErrorAuthenticationFailed:
          {
            //授权失败
            break;
          }
          case LAErrorPasscodeNotSet:
          {
            //系统未设置密码
            break;
          }
          case LAErrorTouchIDNotAvailable:
          {
            //设备Touch ID不可用，例如未打开
            break;
          }
          case LAErrorTouchIDNotEnrolled:
          {
            //设备Touch ID不可用，用户未录入
            break;
          }
          case LAErrorUserFallback:
          {
            [[NSOperationQueue mainQueue] addOperationWithBlock:^{
              //用户选择输入密码，切换主线程处理
            }];
            break;
          }
          default:
          {
            [[NSOperationQueue mainQueue] addOperationWithBlock:^{
              //其他情况，切换主线程处理
            }];
            break;
          }
        }
      }
    }];
  }
  else
  {
    //不支持指纹识别，LOG出错误详情
    NSLog(@"不支持指纹识别");
    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);
  }
}