Android中如何实现指纹验证功能（记录）

如何实现指纹验证？

Android6.0之后就已经开始支持指纹验证了，也就是说Android自带功能。

指纹验证需要哪些注意事项？

（1）Android系统版本大于等于Android6.0；

（2）测试设备是否具有指纹功能。

效果图如下：

步骤如下：

（1）指纹验证对话框布局文件 layout_fingerprint.xml 代码如下：

（2）创建自定义的FragmentDialog对话框来实现相关的监听操作。

public class FingerprintDialogFragment extends DialogFragment {

    private TextView tvErrorInfo, tvCancel;

    private LoginActivity loginActivity;

    private FingerprintManager fingerprintManager;
    private CancellationSignal cancellationSignal;
    private Cipher cipher;

    private boolean isUserCancel;

    public void setCipher(Cipher cipher) {
        this.cipher = cipher;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        loginActivity = (LoginActivity) getActivity();
    }

    @TargetApi(Build.VERSION_CODES.M)
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        fingerprintManager = getContext().getSystemService(FingerprintManager.class);
        setStyle(DialogFragment.STYLE_NORMAL, R.style.Translucent_NoTitle);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.layout_fingerprint, container);
        tvErrorInfo = view.findViewById(R.id.FingerPrint_tvErrorInfo);
        tvCancel = view.findViewById(R.id.FingerPrint_tvCancel);
        tvCancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dismiss();
                stopListener();
            }
        });
        return view;
    }

    @Override
    public void onResume() {
        super.onResume();
        startListener(cipher);
    }

    @Override
    public void onPause() {
        super.onPause();
        stopListener();
    }

    /**
     * 开始指纹认证监听
     *
     * @param mCipher
     */
    @TargetApi(Build.VERSION_CODES.M)
    private void startListener(Cipher mCipher) {
        isUserCancel = false;
        cancellationSignal = new CancellationSignal();
        fingerprintManager.authenticate(new FingerprintManager.CryptoObject(mCipher), cancellationSignal, 0, new FingerprintManager.AuthenticationCallback() {
            @Override
            public void onAuthenticationError(int errorCode, CharSequence errString) {
                if (!isUserCancel) {
                    tvErrorInfo.setText(errString);
                    if (errorCode == FingerprintManager.FINGERPRINT_ERROR_LOCKOUT) {
                        Toast.makeText(loginActivity, errString, Toast.LENGTH_SHORT).show();
                        dismiss();
                    }
                }
            }

            @Override
            public void onAuthenticationHelp(int helpCode, CharSequence helpString) {
                tvErrorInfo.setText(helpString);
            }

            @Override
            public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
                dismiss();
                Toast.makeText(loginActivity, "指纹验证成功", Toast.LENGTH_SHORT).show();
                loginActivity.goMainActivity();
            }

            @Override
            public void onAuthenticationFailed() {
                tvErrorInfo.setText("指纹验证失败，请再试一次");
            }
        }, null);
    }

    /**
     * 停止指纹认证监听
     */
    private void stopListener() {
        if (cancellationSignal != null) {
            cancellationSignal.cancel();
            cancellationSignal = null;
            isUserCancel = true;
        }
    }
}

（3）在相应的Activity界面调用FragmentDialog对话框，相关代码如下：

public class LoginActivity extends AppCompatActivity implements View.OnClickListener {

    private final static String DEFAULT_KEY_NAME = "MyFingerPrint";

    private Context mContext;

    private Button btnConfirm;

    private KeyStore keyStore;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_anotherlogin);

        baseDataInit();
        bindViews();
        viewsAddListener();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
    }

    private void baseDataInit() {
        mContext = this;
    }

    private void bindViews() {
        btnConfirm = findViewById(R.id.AnotherLogin_btnConfirm);
    }

    private void viewsAddListener() {
        btnConfirm.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.AnotherLogin_btnConfirm: {
                if (isSupportFingerPrint()) {
                    keyInit();
                    cipherInit();
                }
                break;
            }
            default:break;
        }
    }

    /**
     * 检查设备是否支持指纹解锁功能
     *
     * @return
     */
    private boolean isSupportFingerPrint() {
        if (Build.VERSION.SDK_INT < 23) {
            Toast.makeText(mContext, "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(mContext, "您的手机不支持指纹功能", Toast.LENGTH_SHORT).show();
                return false;
            } else if (!keyguardManager.isKeyguardSecure()) {
                Toast.makeText(mContext, "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(mContext, "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;
    }

    /**
     * 初始化Keystore
     */
    @TargetApi(Build.VERSION_CODES.M)
    private void keyInit() {
        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);
        }
    }

    /**
     * 初始化密码
     */
    private void cipherInit() {
        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);
        }
    }

    /**
     * 显示指纹验证对话框
     *
     * @param cipher
     */
    private void showFingerPrintDialog(Cipher cipher) {
        FingerprintDialogFragment fragment = new FingerprintDialogFragment();
        fragment.setCipher(cipher);
        fragment.show(getFragmentManager(), "fingerprint");
    }

    /**
     * 进入主界面
     */
    public void goMainActivity() {
        startActivity(new Intent(mContext, MainActivity.class));
    }
}

相应的Demo地址为：https://download.csdn.net/download/lpcrazyboy/11225686