我想使用像素2背面的指纹传感器在点击应用时按下应用中的按钮。
我在文档中为它找到了一些东西，但是看起来它只报告滑动输入而没有输入输入：https://developer.android.com/reference/android/accessibilityservice/FingerprintGestureController.html
答案 0 :(得分：0)
是的。迈克尔·多德（Michael Dodd）讲的是什么。我们可以像指纹识别事件那样成功地获取各种事件，例如指纹成功，失败或被快速删除。敲击事件更有可能快速去除指纹。我没有找到用于获取点击事件的任何直接API。而是使用身份验证来获得自定义活动中的点击。实现以下代码，并找到各种适当的事件来处理tap事件。
@TargetApi(Build.VERSION_CODES.M)
public class FingerprintUiHelper extends FingerprintManager.AuthenticationCallback {
/**
* The timeout for the error to be displayed. Returns to the normal UI after this.
*/
private static final long ERROR_TIMEOUT_MILLIS = 1600;
/**
* The timeout for the success to be displayed. Calls {@link Callback#onAuthenticated()} after this.
*/
private static final long SUCCESS_DELAY_MILLIS = 1300;
/**
* Alias for our key in the Android Key Store
**/
private static final String KEY_NAME = "my_key";
/**
* The {@link Cipher} used to init {@link FingerprintManager}
*/
private Cipher mCipher;
/**
* The {@link KeyStore} used to initiliaze the key {@link #KEY_NAME}
*/
private KeyStore mKeyStore;
/**
* The {@link KeyGenerator} used to generate the key {@link #KEY_NAME}
*/
private KeyGenerator mKeyGenerator;
/**
* The {@link android.hardware.fingerprint.FingerprintManager.CryptoObject}
*/
private final FingerprintManager mFingerprintManager;
/**
* The {@link ImageView} that is used to show the authent state
*/
private final ImageView mIcon;
/**
* The {@link TextView} that is used to show the authent state
*/
private final TextView mErrorTextView;
private final Callback mCallback;
/**
* The {@link CancellationSignal} used after an error happens
*/
private CancellationSignal mCancellationSignal;
/**
* Used if the user cancelled the authentication by himself
*/
private boolean mSelfCancelled;
/**
* Builder class for {@link FingerprintUiHelper} in which injected fields from Dagger
* holds its fields and takes other arguments in the {@link #build} method.
*/
public static class FingerprintUiHelperBuilder {
private final FingerprintManager mFingerPrintManager;
public FingerprintUiHelperBuilder(FingerprintManager fingerprintManager) {
mFingerPrintManager = fingerprintManager;
}
public FingerprintUiHelper build(ImageView icon, TextView errorTextView, Callback callback) {
return new FingerprintUiHelper(mFingerPrintManager, icon, errorTextView,
callback);
}
}
/**
* Constructor for {@link FingerprintUiHelper}. This method is expected to be called from
* only the {@link FingerprintUiHelperBuilder} class.
*/
private FingerprintUiHelper(FingerprintManager fingerprintManager,
ImageView icon, TextView errorTextView, Callback callback) {
mFingerprintManager = fingerprintManager;
mIcon = icon;
mErrorTextView = errorTextView;
mCallback = callback;
}
/**
* Starts listening to {@link FingerprintManager}
*
* @throws SecurityException If the hardware is not available, or the permission are not set
*/
public void startListening() throws SecurityException {
if (initCipher()) {
FingerprintManager.CryptoObject cryptoObject = new FingerprintManager.CryptoObject(mCipher);
if (!isFingerprintAuthAvailable()) {
return;
}
mCancellationSignal = new CancellationSignal();
mSelfCancelled = false;
mFingerprintManager.authenticate(cryptoObject, mCancellationSignal, 0 /* flags */, this, null);
mIcon.setImageResource(R.drawable.ic_fp_40px);
}
}
/**
* Stops listening to {@link FingerprintManager}
*/
public void stopListening() {
if (mCancellationSignal != null) {
mSelfCancelled = true;
mCancellationSignal.cancel();
mCancellationSignal = null;
}
}
/**
* Called by {@link FingerprintManager} if the authentication threw an error.
*/
@Override
public void onAuthenticationError(int errMsgId, CharSequence errString) {
if (!mSelfCancelled) {
showError(errString);
mIcon.postDelayed(new Runnable() {
@Override
public void run() {
mCallback.onError();
}
}, ERROR_TIMEOUT_MILLIS);
}
}
/**
* Called by {@link FingerprintManager} if the user asked for help.
*/
@Override
public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
showError(helpString);
}
/**
* Called by {@link FingerprintManager} if the authentication failed (bad finger etc...).
*/
@Override
public void onAuthenticationFailed() {
showError(mIcon.getResources().getString(
R.string.pin_code_fingerprint_not_recognized));
}
/**
* Called by {@link FingerprintManager} if the authentication succeeded.
*/
@Override
public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
mErrorTextView.removeCallbacks(mResetErrorTextRunnable);
mIcon.setImageResource(R.drawable.ic_fingerprint_success);
mErrorTextView.setTextColor(
mErrorTextView.getResources().getColor(R.color.success_color, null));
mErrorTextView.setText(
mErrorTextView.getResources().getString(R.string.pin_code_fingerprint_success));
mIcon.postDelayed(new Runnable() {
@Override
public void run() {
mCallback.onAuthenticated();
}
}, SUCCESS_DELAY_MILLIS);
}
/**
* Tells if the {@link FingerprintManager#isHardwareDetected()}, {@link FingerprintManager#hasEnrolledFingerprints()},
* and {@link KeyguardManager#isDeviceSecure()}
*
* @return true if yes, false otherwise
* @throws SecurityException If the hardware is not available, or the permission are not set
*/
public boolean isFingerprintAuthAvailable() throws SecurityException {
return mFingerprintManager.isHardwareDetected()
&& mFingerprintManager.hasEnrolledFingerprints()
&& ((KeyguardManager) mIcon.getContext().getSystemService(Context.KEYGUARD_SERVICE)).isDeviceSecure();
}
/**
* Initialize the {@link Cipher} instance with the created key in the {@link #createKey()}
* method.
*
* @return {@code true} if initialization is successful, {@code false} if the lock screen has
* been disabled or reset after the key was generated, or if a fingerprint got enrolled after
* the key was generated.
*/
private boolean initCipher() {
try {
if (mKeyStore == null) {
mKeyStore = KeyStore.getInstance("AndroidKeyStore");
}
createKey();
mKeyStore.load(null);
SecretKey key = (SecretKey) mKeyStore.getKey(KEY_NAME, null);
mCipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
mCipher.init(Cipher.ENCRYPT_MODE, key);
return true;
} catch (NoSuchPaddingException | KeyStoreException | CertificateException | UnrecoverableKeyException | IOException
| NoSuchAlgorithmException | InvalidKeyException e) {
return false;
}
}
/**
* Creates a symmetric key in the Android Key Store which can only be used after the user has
* authenticated with fingerprint.
*/
public void createKey() {
// The enrolling flow for fingerprint. This is where you ask the user to set up fingerprint
// for your flow. Use of keys is necessary if you need to know if the set of
// enrolled fingerprints has changed.
try {
// Set the alias of the entry in Android KeyStore where the key will appear
// and the constrains (purposes) in the constructor of the Builder
mKeyGenerator = KeyGenerator.getInstance(
KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
mKeyGenerator.init(new KeyGenParameterSpec.Builder(KEY_NAME,
KeyProperties.PURPOSE_ENCRYPT |
KeyProperties.PURPOSE_DECRYPT)
.setBlockModes(KeyProperties.BLOCK_MODE_CBC)
// Require the user to authenticate with a fingerprint to authorize every use
// of the key
.setUserAuthenticationRequired(true)
.setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7)
.build());
mKeyGenerator.generateKey();
} catch (NoSuchProviderException | NoSuchAlgorithmException | InvalidAlgorithmParameterException e) {
throw new RuntimeException(e);
}
}
/**
* Show an error on the UI using {@link #mIcon} and {@link #mErrorTextView}
*/
private void showError(CharSequence error) {
mIcon.setImageResource(R.drawable.ic_fingerprint_error);
mErrorTextView.setText(error);
mErrorTextView.setTextColor(
mErrorTextView.getResources().getColor(R.color.warning_color, null));
mErrorTextView.removeCallbacks(mResetErrorTextRunnable);
mErrorTextView.postDelayed(mResetErrorTextRunnable, ERROR_TIMEOUT_MILLIS);
}
/**
* Run by {@link #showError(CharSequence)} with delay to reset the original UI after an error.
*/
Runnable mResetErrorTextRunnable = new Runnable() {
@Override
public void run() {
mErrorTextView.setTextColor(
mErrorTextView.getResources().getColor(R.color.hint_color, null));
mErrorTextView.setText(
mErrorTextView.getResources().getString(R.string.pin_code_fingerprint_text));
mIcon.setImageResource(R.drawable.ic_fp_40px);
}
};
/**
* The interface used to call the original Activity/Fragment... that uses this helper.
*/
public interface Callback {
void onAuthenticated();
void onError();
}