指纹验证这个功能现在在一些app中经常常见，常常与数字解锁，手势解锁联合起来使用。前几天接到说实现一个指纹验证的功能，捣鼓了挺久，然后今天，我就简单的介绍下指纹验证，会做个简单的demo实现一下基本的功能。
支持系统和机型：iOS系统的指纹识别功能最低支持的机型为iPhone 5s，最低支持系统为iOS 8。实现起来呢，其实还是很简单的，下面我们就用纯代码方式实现一个简单的demo1。
第一部分：调用原生服务实现指纹验证
这部分了解个大概就可以了
- 第一步：添加LocalAuthentication.framework库
firstStep.png
secondStep.png
thirdStep.png
- 第二步：在appdelegate.m中添加代码
这个不说其实大家也都知道的吧。
#import "AppDelegate.h"
#import "ViewController.h"
@interface AppDelegate ()
@end
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//appdelegate
_window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
_window.backgroundColor = [UIColor whiteColor];
[_window makeKeyAndVisible];
ViewController *vc = [[ViewController alloc]init];
UINavigationController *na = [[UINavigationController alloc]initWithRootViewController:vc];
_window.rootViewController = na;
return YES;
}
- 第三步
引入头文件
#import <LocalAuthentication/LocalAuthentication.h>
- 第四步：实现指纹验证
这一步就是很重要的地方了，在- (void)viewDidLoad中写入验证实现的代码，这里只有两步，因为LAContext在官方文档中只有两个方法:
-canEvaluatePolicy:error:
//-(BOOL)canEvaluatePolicy:(LAPolicy)policy error:(NSError * __autoreleasing *)error __attribute__((swift_error(none)));
-evaluatePolicy:localizedReason:reply:
//- (void)evaluatePolicy:(LAPolicy)policy localizedReason:(NSString *)localizedReason reply:(void(^)(BOOL success, NSError * __nullable error))reply;
一个是判断设备是否支持touchid，一个是进行验证返回不同的结果，之前在网上经常可以一些文章中写了，指纹验证的第一步都是先判断设备的系统版本等等，现在似乎都不需要了，只要调用该方法就可以了。全部的代码 如下：
- (void)viewDidLoad {
[super viewDidLoad];
self.title = @"TouchIDSimpleDemoOne";
LAContext *context = [[LAContext alloc]init];
NSError *error;
NSString *result = @"需要你身份验证呢";
if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error])
{
[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:result reply:^(BOOL success, NSError *error)
{
if (success)
{
//验证成功，主线程处理UI
//这个地方呢就是写一些验证成功之后需要做些什么事情的代码。
NSLog(@"验证成功");
}
else
{
//以下是一些验证失败的原因啥的
NSLog(@"%@",error.localizedDescription);
switch (error.code) {
case LAErrorSystemCancel:
{
NSLog(@"切换到其他APP，系统取消验证Touch ID");
//切换到其他APP，系统取消验证Touch ID
break;
}
case LAErrorUserCancel:
{
NSLog(@"用户取消验证Touch ID");
//用户取消验证Touch ID
break;
}
case LAErrorUserFallback:
{
NSLog(@"用户选择输入密码");
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
//用户选择其他验证方式，切换主线程处理
}];
break;
}
default:
{
NSLog(@"LAErrorAuthenticationFailed，授权失败");
//授权失败
[[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
switch (error.code) {
case LAErrorTouchIDNotEnrolled:
{
NSLog(@"设备Touch ID不可用，用户未录入");
break;
}
case LAErrorPasscodeNotSet:
{
NSLog(@"系统未设置密码");
break;
}
case LAErrorTouchIDNotAvailable:
{
NSLog(@"设备Touch ID不可用，例如未打开");
break;
}
default:
{
NSLog(@"系统未设置密码");
break;
}
}
NSLog(@"%@",error.localizedDescription);
}
}
//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;这个控件的话，在这个链接上其实已经有写出怎么用了，其实不需要我再都说什么，但是我还是要说下吧。
调用时只需要一两行代码调用，但是回调函数还是需要写不少东西的。。。
- 1:复制文件进去
WJTouchID
- 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;
这些方法实现结束后呢，这个功能也基本上算是完成了。因为好像篇幅太长了，看得人肯定也嫌烦，所以我准备另写一篇做一个在app被唤醒的时候启动指纹验证，分别用弹出控制器和弹出自定义view这两个方式来实现。感兴趣的话可以看下。
