刀哥之指紋識別biometrics

指紋識別 - 生物識別

簡介

• iPhone 5S 開始支持
• iOS 8.0 開放了 Touch ID 的接口

代碼準備

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    [self inputUserinfo];
}

///  輸入用戶信息
- (void)inputUserinfo {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:@"購買" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"購買", nil];
    alertView.alertViewStyle = UIAlertViewStyleLoginAndPasswordInput;

    [alertView show];
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSLog(@"%zd", buttonIndex);

    if (buttonIndex == 0) {
        return;
    }

    UITextField *usernameText = [alertView textFieldAtIndex:0];
    UITextField *pwdText = [alertView textFieldAtIndex:1];

    if ([usernameText.text isEqualToString:@"zhang"] && [pwdText.text isEqualToString:@"123"]) {
        [self purchase];
    } else {
        [[[UIAlertView alloc] initWithTitle:@"提示" message:@"用戶名或密碼錯誤" delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil] show];
    }
}

///  購買
- (void)purchase {
    NSLog(@"購買");
}

指紋識別

頭文件

#import <LocalAuthentication/LocalAuthentication.h>

判斷是否支持指紋識別

// 檢查版本
if ([UIDevice currentDevice].systemVersion.floatValue < 8.0) {
    [self inputUserinfo];
    return;
}

// 檢查是否支持指紋識別
LAContext *ctx = [[LAContext alloc] init];

if ([ctx canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:NULL]) {
    NSLog(@"支持指紋識別");

    // 異步輸入指紋
    [ctx evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"購買" reply:^(BOOL success, NSError *error) {
        NSLog(@"%d %@ %@", success, error, [NSThread currentThread]);
        if (success) {
            [self purchase];
        } else if (error.code == LAErrorUserFallback) {
            dispatch_async(dispatch_get_main_queue(), ^{
                [self inputUserinfo];
            });
        }
    }];
    NSLog(@"come here");
} else {
    [self inputUserinfo];
}

錯誤代號

錯誤	描述
LAErrorAuthenticationFailed	指紋無法識別
LAErrorUserCancel	用戶點擊了”取消”按鈕
LAErrorUserFallback	用戶取消，點擊了”輸入密碼”按鈕
LAErrorSystemCancel	系統取消，例如激活了其他應用程序
LAErrorPasscodeNotSet	驗證無法啓動，因爲設備上沒有設置密碼
LAErrorTouchIDNotAvailable	驗證無法啓動，因爲設備上沒有 Touch ID
LAErrorTouchIDNotEnrolled	驗證無法啓動，因爲沒有輸入指紋

使用 UIAlertController

- (void)inputUserInfo {
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"提示" message:@"請輸入用戶名和口令" preferredStyle:UIAlertControllerStyleAlert];

    [alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"請輸入用戶名";
    }];
    [alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"請輸入用戶密碼";
        textField.secureTextEntry = YES;
    }];

    [alert addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
        [self dismissViewControllerAnimated:YES completion:nil];
    }]];

    [alert addAction:[UIAlertAction actionWithTitle:@"購買" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        NSString *username = [alert.textFields[0] text];
        NSString *pwd = [alert.textFields[1] text];

        if ([username isEqualToString:@"zhang"] && [pwd isEqualToString:@"1"]) {
            [self purchase];
        } else {
            [self showErrorMsg];
        }
    }]];

    [self presentViewController:alert animated:YES completion:nil];
}

- (void)showErrorMsg {
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"提示" message:@"用戶名或密碼不正確" preferredStyle:UIAlertControllerStyleAlert];

    [alert addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
        [self dismissViewControllerAnimated:YES completion:nil];
    }]];

    [self presentViewController:alert animated:YES completion:nil];
}

- (void)purchase {
    NSLog(@"買了");
}