Android 指纹识别

绝地灬酷狼 2024-03-17 22:50 23阅读 0赞

## Android 指纹识别 ##

Android 从 6.0 系统开始就支持指纹认证功能。

将指纹认证功能使用到 APP 的功能逻辑当中是有很多功能场景的，比如说金融银行类 APP 可以使用指纹认证来快速登录，股票证券类 APP 可以使用指纹认证来操作和交易等等。

*  FingerprintManager : 指纹管理工具类
 *  FingerprintManager.AuthenticationCallback :使用验证的时候传入该接口，通过该接口进行验证结果回调
 *  FingerprintManager.CryptoObject: FingerprintManager 支持的分装加密对象的类

> 以上是28以下API 中使用的类 在Android 28版本中google 宣布使用Androidx 库代替Android库，所以在28版本中Android 推荐使用androidx库中的类 所以在本文中我 使用的是推荐是用的FingerprintManagerCompat 二者的使用的方式基本相似

### 一、代码 ###

#### 1.0 添加权限 ####

<uses-permission android:name="android.permission.USE_FINGERPRINT" />

#### 1.1 创建验证对话框布局 ####

开始编写指纹认证界面，新建 fingerprint\_dialog.xml，代码如下所示：

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
    
        <ImageView
            android:id="@+id/image_finger"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:src="@drawable/ic_fp_40px" />
    
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_marginTop="20dp"
            android:text="请验证指纹解锁"
            android:textColor="#000"
            android:textSize="16sp" />
    
        <TextView
            android:id="@+id/error_msg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_marginTop="5dp"
            android:maxLines="1"
            android:textColor="#f45"
            android:textSize="12sp" />
    
        <View
            android:layout_width="match_parent"
            android:layout_height="0.5dp"
            android:layout_marginTop="10dp"
            android:background="#ccc" />
    
        <TextView
            android:id="@+id/cancel"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:text="取消"
            android:textColor="#5d7883"
            android:textSize="16sp" />
    
    </LinearLayout>

这是一个非常简易的指纹认证界面，相信没什么需要解释的地方。界面大致样式如下图所示。

![img][]

Google 也特意提供了一套指纹认证的组图，可以 [点击这里][Link 1] 查看和下载。

#### 1.2 创建FingerprintDialogFragment ####

接着我们创建一个 FingerprintDialogFragment 类，并让它继承自 DialogFragment，用于作为提示用户进行指纹认证的对话框，代码如下所示：

@TargetApi(23)
    public class FingerprintDialogFragment extends DialogFragment {
    
        private FingerprintManager fingerprintManager;
    
        private CancellationSignal mCancellationSignal;
    
        private Cipher mCipher;
    
        private LoginActivity mActivity;
    
        private TextView errorMsg;
    
        /**
         * 标识是否是用户主动取消的认证。
         */
        private boolean isSelfCancelled;
    
        public void setCipher(Cipher cipher) {
            mCipher = cipher;
        }
    
        @Override
        public void onAttach(Context context) {
            super.onAttach(context);
            mActivity = (LoginActivity) getActivity();
        }
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            fingerprintManager = getContext().getSystemService(FingerprintManager.class);
            setStyle(DialogFragment.STYLE_NORMAL, android.R.style.Theme_Material_Light_Dialog);
        }
    
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
            View v = inflater.inflate(R.layout.fingerprint_dialog, container, false);
            errorMsg = v.findViewById(R.id.error_msg);
            TextView cancel = v.findViewById(R.id.cancel);
            cancel.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    dismiss();
                    stopListening();
                }
            });
            return v;
        }
    
        @Override
        public void onResume() {
            super.onResume();
            
            startListening(mCipher);
        }
    
        @Override
        public void onPause() {
            super.onPause();
            
            stopListening();
        }
    
        private void startListening(Cipher cipher) {
            isSelfCancelled = false;
            mCancellationSignal = new CancellationSignal();
            fingerprintManager.authenticate(new FingerprintManager.CryptoObject(cipher), mCancellationSignal, 0, new FingerprintManager.AuthenticationCallback() {
                @Override
                public void onAuthenticationError(int errorCode, CharSequence errString) {
                    if (!isSelfCancelled) {
                        errorMsg.setText(errString);
                        if (errorCode == FingerprintManager.FINGERPRINT_ERROR_LOCKOUT) {
                            Toast.makeText(mActivity, errString, Toast.LENGTH_SHORT).show();
                            dismiss();
                        }
                    }
                }
    
                @Override
                public void onAuthenticationHelp(int helpCode, CharSequence helpString) {
                    errorMsg.setText(helpString);
                }
    
                @Override
                public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
                    Toast.makeText(mActivity, "指纹认证成功", Toast.LENGTH_SHORT).show();
                    mActivity.onAuthenticated();
                }
    
                @Override
                public void onAuthenticationFailed() {
                    errorMsg.setText("指纹认证失败，请再试一次");
                }
            }, null);
        }
    
        private void stopListening() {
            if (mCancellationSignal != null) {
                mCancellationSignal.cancel();
                mCancellationSignal = null;
                isSelfCancelled = true;
            }
        }
    
    }

setCipher() 方法用于接受一个 Cipher 对象，这个参数在待会进行指纹认证的时候会用到。

#### 1.3 解释dialog中的内容 ####

接下来几个生命周期方法都很简单，在 onAttach() 方法中获取了 Activity 的实例，在 onCreate() 方法获取了 FingerprintManager 的实例，在 onCreateView() 方法中加载了我们刚刚创建的 fingerprint\_dialog.xml 布局，都是一些常规操作。

紧接着重点的要来了，在 onResume() 方法中调用了 startListening() 方法开始指纹认证监听，在 onPause() 方法中调用了 stopListening() 方法停止指纹认证监听。为什么要这么做呢？因为指纹传感器和摄像头类似，是不能多个程序同时使用的，因此任何一个程序都不应该在非前台时刻占用着指纹传感器的资源，所以需要在 onPause() 方法中及时释放资源。

那么，现在我们只需要把所有的目光都放在 startListening() 和 stopListening() 这两个方法上就可以了。在 startListening() 方法中，调用了 FingerprintManager 的 authenticate() 方法来开启指纹指纹监听。authenticate() 方法接收五个参数，第一个参数是 CryptoObject 对象，这里我们只需要将刚才传入的 Cipher 对象包装成 CryptoObject 对象就可以了。第二个参数是 CancellationSignal 对象，可以使用它来取消指纹认证操作。第三个参数是可选参数，官方的建议是直接传 0 就可以了。第四个参数用于接收指纹认证的回调，上述代码中我将所有的回调可能都进行了界面提示，方便大家观察。第五个参数用于指定处理回调的 Handler，这里直接传 null 表示回调到主线程即可。

而在 stopListening() 方法中的逻辑则简单得多了，我们只需要调用 CancellationSignal 的 cancel() 方法将指纹认证操作取消就可以了。

这样我们就将 FingerprintDialogFragment 中的代码全部完成了，这段代码可以直接复制到任意项目当中来作为指纹认证提醒对话框。

#### 1.4 创建登陆界面 ####

最后，我们再来编写一个简单的登录界面，整个指纹认证过程就完整了。创建 LoginActivity，代码如下所示：

public class LoginActivity extends AppCompatActivity {
    
        private static final String DEFAULT_KEY_NAME = "default_key";
    
        KeyStore keyStore;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_login);
            if (supportFingerprint()) {
                initKey();
                initCipher();
            }
        }
    
        public boolean supportFingerprint() {
            if (Build.VERSION.SDK_INT < 23) {
                Toast.makeText(this, "您的系统版本过低，不支持指纹功能", Toast.LENGTH_SHORT).show();
                return false;
            } else {
                KeyguardManager keyguardManager = getSystemService(KeyguardManager.class);
                FingerprintManager fingerprintManager = getSystemService(FingerprintManager.class);
                if (!fingerprintManager.isHardwareDetected()) {
                    Toast.makeText(this, "您的手机不支持指纹功能", Toast.LENGTH_SHORT).show();
                    return false;
                } else if (!keyguardManager.isKeyguardSecure()) {
                    Toast.makeText(this, "您还未设置锁屏，请先设置锁屏并添加一个指纹", Toast.LENGTH_SHORT).show();
                    return false;
                } else if (!fingerprintManager.hasEnrolledFingerprints()) {
                    Toast.makeText(this, "您至少需要在系统设置中添加一个指纹", Toast.LENGTH_SHORT).show();
                    return false;
                }
            }
            return true;
        }
    
        @TargetApi(23)
        private void initKey() {
            try {
                keyStore = KeyStore.getInstance("AndroidKeyStore");
                keyStore.load(null);
                KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
                KeyGenParameterSpec.Builder builder = new KeyGenParameterSpec.Builder(DEFAULT_KEY_NAME,
                        KeyProperties.PURPOSE_ENCRYPT |
                                KeyProperties.PURPOSE_DECRYPT)
                        .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
                        .setUserAuthenticationRequired(true)
                        .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7);
                keyGenerator.init(builder.build());
                keyGenerator.generateKey();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    
        @TargetApi(23)
        private void initCipher() {
            try {
                SecretKey key = (SecretKey) keyStore.getKey(DEFAULT_KEY_NAME, null);
                Cipher cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
                        + KeyProperties.BLOCK_MODE_CBC + "/"
                        + KeyProperties.ENCRYPTION_PADDING_PKCS7);
                cipher.init(Cipher.ENCRYPT_MODE, key);
                showFingerPrintDialog(cipher);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    
        private void showFingerPrintDialog(Cipher cipher) {
            FingerprintDialogFragment fragment = new FingerprintDialogFragment();
            fragment.setCipher(cipher);
            fragment.show(getFragmentManager(), "fingerprint");
        }
    
        public void onAuthenticated() {
            Intent intent = new Intent(this, MainActivity.class);
            startActivity(intent);
            finish();
        }
    
    }

\*\*首先在 onCreate() 方法中，调用了 supportFingerprint() 方法来判断当前设备是否支持指纹认证功能。\*\*这一点是非常重要的，因为当设备不支持指纹认证的时候，还需要及时切换到如图案、密码等其他的认证方式。

当设备支持指纹认证的时候，再分为两步，第一步生成一个对称加密的 Key，第二步生成一个 Cipher 对象，这都是 Android 指纹认证 API 要求的标准用法。得到了 Cipher 对象之后，我们创建 FingerprintDialogFragment 的实例，并将 Cipher 对象传入，再将 FingerprintDialogFragment 显示出来就可以了。

#### 1.5 认证成功跳到主界面 ####

当指纹认证成功之后，会在 FingerprintDialogFragment 的回调当中调用 LoginActivity 的 onAuthenticated() 方法，然后界面会跳转到 MainActivity，整个指纹认证过程就此结束。

打开应用之后会立刻弹出指纹认证对话框，此时先使用错误的手指来进行认证：

![在这里插入图片描述][1e722899a2d4a3bcea082ece40109433.webp]

可以看到，当指纹验证失败的时候，会在界面上显示相应的错误提示信息。

接下来使用正确的手指来进行认证：

![img][img 1]

OK，指纹验证成功，并自动跳转到了 MainActivity 界面。

[源码][Link 2]

#### 1.6 手机验证的次数 ####

手机指纹识别的验证的次数是有限制的，一段时间内，大概只能识别5次。5次后就要等大概1分钟后才能重新识别。

@TargetApi(23)
    public class FingerprintDialogFragment extends DialogFragment {
    
        private FingerprintManager fingerprintManager;
    
        private CancellationSignal mCancellationSignal;
    
        private Cipher mCipher;
    
        private LoginActivity mActivity;
    
        private TextView errorMsg;
    
        //识别的次数
        private int mCount = 5;
    
        /**
         * 标识是否是用户主动取消的认证。
         */
        private boolean isSelfCancelled;
    
        public void setCipher(Cipher cipher) {
            mCipher = cipher;
        }
    
        @Override
        public void onAttach(Context context) {
            super.onAttach(context);
            mActivity = (LoginActivity) getActivity();
        }
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            fingerprintManager = getContext().getSystemService(FingerprintManager.class);
            setStyle(DialogFragment.STYLE_NORMAL, android.R.style.Theme_Material_Light_Dialog);
        }
    
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
            //不消失
            getDialog().setCancelable(false);
            getDialog().setCanceledOnTouchOutside(false);
            //点击返回键不消失
            getDialog().setOnKeyListener((dialog, keyCode, event) -> {
                if (keyCode == KeyEvent.KEYCODE_BACK)
                    return true;
                return false;
            });
            View v = inflater.inflate(R.layout.fingerprint_dialog, container, false);
            errorMsg = v.findViewById(R.id.error_msg);
            TextView cancel = v.findViewById(R.id.cancel);
            cancel.setOnClickListener(v1 -> {
                dismiss();
                stopListening();
            });
    
            return v;
        }
    
        @Override
        public void onResume() {
            super.onResume();
    
            startListening(mCipher);
        }
    
        @Override
        public void onPause() {
            super.onPause();
    
            stopListening();
        }
    
        private void startListening(Cipher cipher) {
            isSelfCancelled = false;
            mCancellationSignal = new CancellationSignal();
            fingerprintManager.authenticate(new FingerprintManager.CryptoObject(cipher), mCancellationSignal, 0, new FingerprintManager.AuthenticationCallback() {
                @Override
                public void onAuthenticationError(int errorCode, CharSequence errString) {
                    Log.i("zxd", "onAuthenticationError: " + mCount);
                    if (!isSelfCancelled) {
                        errorMsg.setText(errString);
                        if (errorCode == FingerprintManager.FINGERPRINT_ERROR_LOCKOUT) {
                            Toast.makeText(mActivity, errString, Toast.LENGTH_SHORT).show();
                            dismiss();
                        }
                        mCount = 5;
                    }
                }
    
                @Override
                public void onAuthenticationHelp(int helpCode, CharSequence helpString) {
                    errorMsg.setText(helpString);
                }
    
                @Override
                public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
                    Toast.makeText(mActivity, "指纹认证成功", Toast.LENGTH_SHORT).show();
                    mActivity.onAuthenticated();
                }
    
                @Override
                public void onAuthenticationFailed() {
                    if (mCount > 1) {
                        mCount--;
                        errorMsg.setText("指纹不匹配，还可以尝试" + mCount + "次");
                    } else
                        errorMsg.setText("指纹认证失败，请再试一次");
                }
            }, null);
        }
    
        private void stopListening() {
            if (mCancellationSignal != null) {
                mCancellationSignal.cancel();
                mCancellationSignal = null;
                isSelfCancelled = true;
            }
        }
    
    }

在`onAuthenticationError`中，可以使用handler提示“延迟多少s”才能继续识别。

对话框中有“取消”按钮，如果在识别的过程中，识别2次，再继续打开对话框还是从5次开始，这是不对的，因为手机的次数耗掉了2次！

public class LoginActivity extends AppCompatActivity {
    
        private static final String DEFAULT_KEY_NAME = "default_key";
    
        KeyStore keyStore;
        private FingerprintDialogFragment fragment;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_login);
            if (supportFingerprint()) {
                initKey();
                initCipher();
            }
            //再次打开指纹识别
            ImageView iv = findViewById(R.id.image_finger);
            iv.setOnClickListener(v -> {
                if (fragment != null) {
                    fragment.show(getSupportFragmentManager(), "fingerprint");
                }
            });
        }
    
        public boolean supportFingerprint() {
            if (Build.VERSION.SDK_INT < 23) {
                Toast.makeText(this, "您的系统版本过低，不支持指纹功能", Toast.LENGTH_SHORT).show();
                return false;
            } else {
                KeyguardManager keyguardManager = getSystemService(KeyguardManager.class);
                FingerprintManager fingerprintManager = getSystemService(FingerprintManager.class);
                if (!fingerprintManager.isHardwareDetected()) {
                    Toast.makeText(this, "您的手机不支持指纹功能", Toast.LENGTH_SHORT).show();
                    return false;
                } else if (!keyguardManager.isKeyguardSecure()) {
                    Toast.makeText(this, "您还未设置锁屏，请先设置锁屏并添加一个指纹", Toast.LENGTH_SHORT).show();
                    return false;
                } else if (!fingerprintManager.hasEnrolledFingerprints()) {
                    Toast.makeText(this, "您至少需要在系统设置中添加一个指纹", Toast.LENGTH_SHORT).show();
                    return false;
                }
            }
            return true;
        }
    
        @TargetApi(23)
        private void initKey() {
            try {
                keyStore = KeyStore.getInstance("AndroidKeyStore");
                keyStore.load(null);
                KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
                KeyGenParameterSpec.Builder builder = new KeyGenParameterSpec.Builder(DEFAULT_KEY_NAME,
                        KeyProperties.PURPOSE_ENCRYPT |
                                KeyProperties.PURPOSE_DECRYPT)
                        .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
                        .setUserAuthenticationRequired(true)
                        .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7);
                keyGenerator.init(builder.build());
                keyGenerator.generateKey();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    
        @TargetApi(23)
        private void initCipher() {
            try {
                SecretKey key = (SecretKey) keyStore.getKey(DEFAULT_KEY_NAME, null);
                Cipher cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
                        + KeyProperties.BLOCK_MODE_CBC + "/"
                        + KeyProperties.ENCRYPTION_PADDING_PKCS7);
                cipher.init(Cipher.ENCRYPT_MODE, key);
                showFingerPrintDialog(cipher);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    
        private void showFingerPrintDialog(Cipher cipher) {
            fragment = new FingerprintDialogFragment();
            fragment.setCipher(cipher);
            fragment.show(getSupportFragmentManager(), "fingerprint");
        }
    
        public void onAuthenticated() {
            Intent intent = new Intent(this, MainActivity.class);
            startActivity(intent);
            finish();
        }
    }

将fragment提取出来，点击的再次显示对话框的时候，直接显示就行，不需要重新创建

#### 1.7 手机验证失败，增加抖动效果 ####

利用识别对话框中的指纹图片，进行左右晃动

@TargetApi(23)
    public class FingerprintDialogFragment extends DialogFragment {
    
        ....
    
        private TranslateAnimation mAnimation;
        private ImageView mShakeImage;
        ...
    
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        	...
            //创建动画
            mShakeImage = v.findViewById(R.id.image_finger);
            mAnimation = new TranslateAnimation(0, 5, 0, 0);
            mAnimation.setDuration(800);
            mAnimation.setInterpolator(new CycleInterpolator(8));
    
            return v;
        }
    
        private void startListening(Cipher cipher) {
            isSelfCancelled = false;
            mCancellationSignal = new CancellationSignal();
            fingerprintManager.authenticate(new FingerprintManager.CryptoObject(cipher), mCancellationSignal, 0, new FingerprintManager.AuthenticationCallback() {
                @Override
                public void onAuthenticationError(int errorCode, CharSequence errString) {
                    Log.i("zxd", "onAuthenticationError: " + mCount);
                    if (!isSelfCancelled) {
                        errorMsg.setText(errString);
                        if (errorCode == FingerprintManager.FINGERPRINT_ERROR_LOCKOUT) {
                            Toast.makeText(mActivity, errString, Toast.LENGTH_SHORT).show();
                            dismiss();
                        }
                        mCount = 5;
                    }
                }
    
                @Override
                public void onAuthenticationHelp(int helpCode, CharSequence helpString) {
                    errorMsg.setText(helpString);
                }
    
                @Override
                public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
                    Toast.makeText(mActivity, "指纹认证成功", Toast.LENGTH_SHORT).show();
                    mActivity.onAuthenticated();
                }
    
                @Override
                public void onAuthenticationFailed() {
                    if (mCount > 1) {
                        mCount--;
                        errorMsg.setText("指纹不匹配，还可以尝试" + mCount + "次");
                    } else
                        errorMsg.setText("指纹认证失败，请再试一次");
                    mShakeImage.startAnimation(mAnimation);
                }
            }, null);
        }
    
        ...
    }

动画也可以使用资源文件

Animation shakeAnimation = AnimationUtils.loadAnimation(PatternCheckActivity.this, R.anim.shake);
    binding.patternCheckTv.startAnimation(shakeAnimation);

shake.xml

<?xml version="1.0" encoding="utf-8"?>
    <translate xmlns:android="http://schemas.android.com/apk/res/android"
        android:duration="1000"
        android:fromXDelta="0"
        android:interpolator="@anim/cycle_7"
        android:toXDelta="10" />

cycle\_7.xml

#### 1.8 对话框取消 ####

识别对话框只能点取消按钮关闭，点击其他区域不能关闭！

在`FingerprintDialogFragment` 的`onCreateView`中增加如下代码

@Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        //不消失
        getDialog().setCancelable(false);
        getDialog().setCanceledOnTouchOutside(false);
        //点击返回键不消失
        getDialog().setOnKeyListener((dialog, keyCode, event) -> {
            if (keyCode == KeyEvent.KEYCODE_BACK)
                return true;
            return false;
        });
        View v = inflater.inflate(R.layout.fingerprint_dialog, container, false);
        errorMsg = v.findViewById(R.id.error_msg);
        TextView cancel = v.findViewById(R.id.cancel);
        cancel.setOnClickListener(v1 -> {
            dismiss();
            stopListening();
        });
    
        return v;
    }

#### 1.9 登陆界面修改 ####

到1.8基本上可以了，但是我看银行指纹登陆界面不错，就想实现一下

首先修改下activity\_login.xml

<?xml version="1.0" encoding="utf-8"?>
    <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".activity.LoginActivity">
    
        <com.zg.smarttime.widget.CircleImageView
            android:id="@+id/login_image"
            android:layout_width="@dimen/dp_100"
            android:layout_height="@dimen/dp_100"
            android:layout_marginTop="@dimen/dp_20"
            android:src="@drawable/autherimg"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <TextView
            android:id="@+id/login_tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:padding="@dimen/dp_8"
            android:text="欢迎回来"
            android:textColor="@android:color/holo_orange_dark"
            android:textSize="@dimen/sp_20"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/login_image" />
    
        <ImageView
            android:id="@+id/image_finger"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="@dimen/dp_100"
            android:src="@drawable/ic_fp_40px"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/dp_140"
            android:gravity="center"
            android:padding="@dimen/dp_8"
            android:text="点击进行指纹登陆"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/image_finger" />
    
    </androidx.constraintlayout.widget.ConstraintLayout>

增加了一个圆形头像，问好的文本，指纹的图片，用于重新打开识别对话框，一个文本提示用户进行识别

public class LoginActivity extends AppCompatActivity {
    
        private static final String DEFAULT_KEY_NAME = "default_key";
    
        KeyStore keyStore;
        private FingerprintDialogFragment fragment;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_login);
            if (supportFingerprint()) {
                initKey();
                initCipher();
            }
            //再次打开指纹识别
            ImageView iv = findViewById(R.id.image_finger);
            iv.setOnClickListener(v -> {
                if (fragment != null) {
                    fragment.show(getSupportFragmentManager(), "fingerprint");
                }
            });
    
            TextView loginTv = findViewById(R.id.login_tv);
            loginTv.setText(DateUtils.getDateSx() + "！");
        }
    
        public boolean supportFingerprint() {
            if (Build.VERSION.SDK_INT < 23) {
                Toast.makeText(this, "您的系统版本过低，不支持指纹功能", Toast.LENGTH_SHORT).show();
                return false;
            } else {
                KeyguardManager keyguardManager = getSystemService(KeyguardManager.class);
                FingerprintManager fingerprintManager = getSystemService(FingerprintManager.class);
                if (!fingerprintManager.isHardwareDetected()) {
                    Toast.makeText(this, "您的手机不支持指纹功能", Toast.LENGTH_SHORT).show();
                    return false;
                } else if (!keyguardManager.isKeyguardSecure()) {
                    Toast.makeText(this, "您还未设置锁屏，请先设置锁屏并添加一个指纹", Toast.LENGTH_SHORT).show();
                    return false;
                } else if (!fingerprintManager.hasEnrolledFingerprints()) {
                    Toast.makeText(this, "您至少需要在系统设置中添加一个指纹", Toast.LENGTH_SHORT).show();
                    return false;
                }
            }
            return true;
        }
    
        @TargetApi(23)
        private void initKey() {
            try {
                keyStore = KeyStore.getInstance("AndroidKeyStore");
                keyStore.load(null);
                KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
                KeyGenParameterSpec.Builder builder = new KeyGenParameterSpec.Builder(DEFAULT_KEY_NAME,
                        KeyProperties.PURPOSE_ENCRYPT |
                                KeyProperties.PURPOSE_DECRYPT)
                        .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
                        .setUserAuthenticationRequired(true)
                        .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7);
                keyGenerator.init(builder.build());
                keyGenerator.generateKey();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    
        @TargetApi(23)
        private void initCipher() {
            try {
                SecretKey key = (SecretKey) keyStore.getKey(DEFAULT_KEY_NAME, null);
                Cipher cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
                        + KeyProperties.BLOCK_MODE_CBC + "/"
                        + KeyProperties.ENCRYPTION_PADDING_PKCS7);
                cipher.init(Cipher.ENCRYPT_MODE, key);
                showFingerPrintDialog(cipher);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    
        private void showFingerPrintDialog(Cipher cipher) {
            fragment = new FingerprintDialogFragment();
            fragment.setCipher(cipher);
            fragment.show(getSupportFragmentManager(), "fingerprint");
        }
    
        public void onAuthenticated() {
            Intent intent = new Intent(this, MainActivity.class);
            startActivity(intent);
            finish();
        }
    }

问好代码，根据日历中hour进行判断

/***
     * 根据Calendar的hour来判断
     */
    public static String getDateSx() {
        String nihao = "";
        Calendar cal = Calendar.getInstance();
        int hour = cal.get(Calendar.HOUR_OF_DAY);
        if (hour >= 6 && hour < 8) {
            System.out.println("早上好");
            nihao = "早上好";
        } else if (hour >= 8 && hour < 11) {
            System.out.print("上午好");
            nihao = "上午好";
        } else if (hour >= 11 && hour < 13) {
            System.out.print("中午好");
            nihao = "中午好";
        } else if (hour >= 13 && hour < 18) {
            System.out.print("下午好");
            nihao = "下午好";
        } else {
            System.out.print("晚上好");
            nihao = "晚上好";
        }
        return nihao;
    }

### 二、参考 ###

[Android指纹识别API讲解，一种更快更好的用户体验][Android_API]

[Android指纹识别认识和基本使用详解][Android]

[Android 指纹识别（给应用添加指纹解锁）][Android 1]

[Google代码][Google]

[kt代码][kt]

[DialogFragment点击背景透明区域不可取消的设置][DialogFragment]

[img]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/e9c8a96755794858bead4ca4792d1556.png
[Link 1]: https://link.juejin.cn/?target=https%3A%2F%2Fgithub.com%2Fgooglesamples%2Fandroid-FingerprintDialog%2Fblob%2Fmaster%2FApplication%2Fsrc%2Fmain%2Fres%2Fdrawable-xxhdpi%2Fic_fp_40px.png
[1e722899a2d4a3bcea082ece40109433.webp]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/06551233a2ad4e43b9fbf8ced40eeced.png
[img 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/c3cd1f13209949d8bcf93bede517a60a.png
[Link 2]: https://link.juejin.cn/?target=https%3A%2F%2Fdownload.csdn.net%2Fdownload%2Fsinyu890807%2F10616306
[Android_API]: https://juejin.cn/post/6965444489984868389
[Android]: https://www.mianshigee.com/note/detail/71092tin/
[Android 1]: https://juejin.cn/post/7210220134601572410#heading-4
[Google]: https://github.com/googlearchive/android-FingerprintDialog/blob/master/Application/src/main/java/com/example/android/fingerprintdialog/MainActivity.java
[kt]: https://github.com/kongxiaoan/FingerprintDemo/blob/master/app/src/main/java/com/kpa/fingerprintdemo/FingerprintDialog.kt
[DialogFragment]: https://blog.csdn.net/chengcanyue/article/details/88551405