Gutes Beispiel für eine Customice DialogPreference gesucht ..

public class PasswordPreference extends DialogPreference {
    private String  sPassword="";
    private EditText Password =null;


    private int mDialogLayoutResId = R.layout.password_pref_layout;


    public PasswordPreference(Context context){
        this(context, null);
    }


    public PasswordPreference(Context context, AttributeSet attrs) {
        this(context, null,0);
    }


    public PasswordPreference(Context context, AttributeSet attrs,
                          int defStyleAttr) {
        this(context, attrs, defStyleAttr, defStyleAttr);
    }


    public PasswordPreference(Context context, AttributeSet attrs,
                          int defStyleAttr, int defStyleRes) {


        super(context, attrs, defStyleAttr, defStyleRes);
//        setWidgetLayoutResource(mDialogLayoutResId);
        setDialogLayoutResource(mDialogLayoutResId);
        setPositiveButtonText(android.R.string.ok);
        setNegativeButtonText(android.R.string.cancel);
     }


     /*
     * Gets the text from the {@link SharedPreferences}.
     *
     * @return The current preference value.
     */
    public String getText() {
        return sPassword;
    }


     public String getPassword(){
        return sPassword;
     }


     public void setPassword(String sPass){
         sPassword=sPass;
         persistString(sPassword);
     }


    @Override
    public CharSequence getSummary() {
        return super.getSummary();
    }


    @Override
    public void setSummary(CharSequence sSum){


    }


    @Override
    protected Object onGetDefaultValue(TypedArray a, int index) {
        // Default value from attribute. Fallback value is set to 0.
        return a.getString(index);
    }


    @Override
    public int getDialogLayoutResource() {
        return mDialogLayoutResId;
    }
}

public class PasswordPreferenceDialogFragmentCompat extends PreferenceDialogFragmentCompat {
    EditText Password;
    EditText ConfirmPassword;
    EncryptedData encData = null;
    private static final int SALT_BYTES = 8;
    private static final int PBK_ITERATIONS = 1000;
    private static final String ENCRYPTION_ALGORITHM = "AES/CBC/PKCS5Padding";
    private static final String PBE_ALGORITHM = "PBEwithSHA256and128BITAES-CBC-BC";
    private static final String USED_PASSWORD ="ParkPlatzHilfe!1234";


    @Override
    public void onDialogClosed(boolean positiveResult) {
    String sPassword;


        if(positiveResult) {
            sPassword = Password.getText().toString();
            // Get the related Preference and save the value
            DialogPreference preference = getPreference();
            if (preference instanceof PasswordPreference) {
                PasswordPreference passwordPreference =
                        ((PasswordPreference) preference);
                // This allows the client to ignore the user value.
                if (passwordPreference.callChangeListener(
                        sPassword)) {
                    // Save the value
                    passwordPreference.setPassword(sPassword);
                }
            }
        }
    }


    public static PasswordPreferenceDialogFragmentCompat newInstance(
            String key) {
        final PasswordPreferenceDialogFragmentCompat
                fragment = new PasswordPreferenceDialogFragmentCompat();
        final Bundle b = new Bundle(1);
        b.putString(ARG_KEY, key);
        fragment.setArguments(b);


        return fragment;
    }


    @Override
    protected void onBindDialogView(View view) {
        super.onBindDialogView(view);


        Password= view.findViewById(R.id.editPassword);


        // Get the password from the related Preference
        String sPass = null;
        DialogPreference preference = getPreference();
        if (preference instanceof PasswordPreference) {
            sPass=((PasswordPreference) preference).getPassword();
        }
        if(sPass != null){
            Password.setText(sPass);
        }
    }


    /*
         String password = "ParkPlatzHilfe!1234";
         byte[] data = sPassword.getBytes("UTF-8");
         EncryptedData encData = encrypt(password, data);
         byte[] decryptedData = decrypt(password, encData.salt, encData.iv, encData.encryptedData);
         String decDataAsString = new String(decryptedData, "UTF-8");


      */
    private static class EncryptedData {
        public byte[] salt;
        public byte[] iv;
        public byte[] encryptedData;
    }


    private EncryptedData encrypt(String password, byte[] data) throws NoSuchPaddingException,
            NoSuchAlgorithmException,
            InvalidKeySpecException,
            InvalidKeyException,
            BadPaddingException,
            IllegalBlockSizeException,
            InvalidAlgorithmParameterException {
        EncryptedData encData = new EncryptedData();
        SecureRandom rnd = new SecureRandom();
        encData.salt = new byte[SALT_BYTES];
        encData.iv = new byte[16]; // AES block size
        rnd.nextBytes(encData.salt);
        rnd.nextBytes(encData.iv);


        PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray(), encData.salt, PBK_ITERATIONS);
        SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance(PBE_ALGORITHM);
        Key key = secretKeyFactory.generateSecret(keySpec);
        Cipher cipher = Cipher.getInstance(ENCRYPTION_ALGORITHM);
        IvParameterSpec ivSpec = new IvParameterSpec(encData.iv);
        cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
        encData.encryptedData = cipher.doFinal(data);
        return encData;
    }


    private byte[] decrypt(String password, byte[] salt, byte[] iv, byte[] encryptedData) throws NoSuchAlgorithmException,
            InvalidKeySpecException,
            NoSuchPaddingException,
            InvalidKeyException,
            BadPaddingException,
            IllegalBlockSizeException,
            InvalidAlgorithmParameterException {
        PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, PBK_ITERATIONS);
        SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance(PBE_ALGORITHM);
        Key key = secretKeyFactory.generateSecret(keySpec);
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        IvParameterSpec ivSpec = new IvParameterSpec(iv);
        cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
        return cipher.doFinal(encryptedData);
    }


    //return the password in asterisks
    private String setAsterisks(int length) {
        StringBuilder sb = new StringBuilder();
        for (int s = 0; s < length; s++) {
            sb.append("*");
        }
        return sb.toString();
    }
}