//指纹验证返回值
typedef NS_ENUM(NSInteger, LAError)
{
/// Authentication was not successful, because user failed to provide valid credentials.
LAErrorAuthenticationFailed = kLAErrorAuthenticationFailed,
/// Authentication was canceled by user (e.g. tapped Cancel button).
LAErrorUserCancel = kLAErrorUserCancel,
/// Authentication was canceled, because the user tapped the fallback button (Enter Password).
LAErrorUserFallback = kLAErrorUserFallback,
/// Authentication was canceled by system (e.g. another application went to foreground).
LAErrorSystemCancel = kLAErrorSystemCancel,
/// Authentication could not start, because passcode is not set on the device.
LAErrorPasscodeNotSet = kLAErrorPasscodeNotSet,
/// Authentication could not start, because Touch ID is not available on the device.
LAErrorTouchIDNotAvailable = kLAErrorTouchIDNotAvailable,
/// Authentication could not start, because Touch ID has no enrolled fingers.
LAErrorTouchIDNotEnrolled = kLAErrorTouchIDNotEnrolled,
/// Authentication was not successful, because there were too many failed Touch ID attempts and
/// Touch ID is now locked. Passcode is required to unlock Touch ID, e.g. evaluating
/// LAPolicyDeviceOwnerAuthenticationWithBiometrics will ask for passcode as a prerequisite.
LAErrorTouchIDLockout NS_ENUM_AVAILABLE(10_11, 9_0) = kLAErrorTouchIDLockout,
/// Authentication was canceled by application (e.g. invalidate was called while
/// authentication was in progress).
LAErrorAppCancel NS_ENUM_AVAILABLE(10_11, 9_0) = kLAErrorAppCancel,
/// LAContext passed to this call has been previously invalidated.
LAErrorInvalidContext NS_ENUM_AVAILABLE(10_11, 9_0) = kLAErrorInvalidContext
} NS_ENUM_AVAILABLE(10_10, 8_0);
以上呢，就是一个简单的demo了，可能有些小问题，到时候需要的话可以自调整。这里附上这个demo的guithub链接看这里看这里，链接在这呢。
第二部分：利用现有的第三方组件实现
这个部分可以好好学习一下。
在这里呢，我要推荐一个别人写的一个第三方的组件，就是[WJTouchID](https://www.easck.com/>
2:引入头文件
#import "WJTouchID.h"
3:遵守协议
@interface ViewController ()<WJTouchIDDelegate>
4: 创建对象
@property (nonatomic, strong) WJTouchID *touchID;
5:调用
- (void)viewDidLoad {
[super viewDidLoad];
//初始化
WJTouchID *touchid = [[WJTouchID alloc]init];
[touchid startWJTouchIDWithMessage:WJNotice(@"自定义信息", @"The Custom Message") fallbackTitle:WJNotice(@"", @"Fallback Title") delegate:self];
self.touchID = touchid;
}
6:实现回调函数
@required
//TouchID验证成功
- (void)WJTouchIDAuthorizeSuccess;
//TouchID验证失败
- (void)WJTouchIDAuthorizeFailure;
@optional
//当前设备不支持指纹识别
- (void)WJTouchIDIsNotSupport;
//当前软件被挂起取消了授权(如突然来了电话,应用进入前台)
- (void)WJTouchIDAuthorizeErrorAppCancel;
//取消TouchID验证 (用户点击了取消)
- (void)WJTouchIDAuthorizeErrorUserCancel;
//在TouchID对话框中点击输入密码按钮
- (void)WJTouchIDAuthorizeErrorUserFallback;
//在验证的TouchID的过程中被系统取消 例如突然来电话、按了Home键、锁屏...
- (void)WJTouchIDAuthorizeErrorSystemCancel;
//无法启用TouchID,设备没有设置密码
- (void)WJTouchIDAuthorizeErrorPasscodeNotSet;
//多次连续使用Touch ID失败，Touch ID被锁，需要用户输入密码解锁
- (void)WJTouchIDAuthorizeErrorTouchIDLockout;
//当前软件被挂起取消了授权 (授权过程中,LAContext对象被释)
- (void)WJTouchIDAuthorizeErrorInvalidContext;
//设备没有录入TouchID,无法启用TouchID
- (void)WJTouchIDAuthorizeErrorTouchIDNotEnrolled;
//该设备的TouchID无效
- (void)WJTouchIDAuthorizeErrorTouchIDNotAvailable;
