问Android:可发现类型；不能将android.preference.Preference转换为androidx.preference.SeekBarPreference

EN

package com.example.myapplication;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.graphics.Color;
import android.os.Bundle;
import android.preference.EditTextPreference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.Preference;
import android.widget.EditText;

import androidx.preference.SeekBarPreference;

public class MyPreferencesActivity extends PreferenceActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();
    }

    public static class MyPreferenceFragment extends PreferenceFragment
    {
        @Override
        public void onCreate(final Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(R.xml.preferences);

            // Retrieve the EditTextPreference demonstrating the font size
            final EditTextPreference fontSizeEditPreference = (EditTextPreference) findPreference("font_size_edittext");
            // Retrive the EditText component of the EditTextPreference
            final EditText fontSizeEditText = fontSizeEditPreference.getEditText();

            // Attach a listener to the font size seekbar (changes the size of the EditText)
            final SeekBarPreference fontSizeSeekBar = (SeekBarPreference) findPreference("font_size");

        }
    }

}

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <com.kizitonwose.colorpreference.ColorPreference
        android:defaultValue="#FF8983"
        android:title="Addition Highlight Color"
        app:colorChoices="@array/highlight_colors"
        android:key="addition_highlight_color"/>

    <com.kizitonwose.colorpreference.ColorPreference
        android:defaultValue="#99ffcc"
        android:title="Removal Highlight Color"
        app:colorChoices="@array/highlight_colors"
        android:key="removal_highlight_color"/>

    <SeekBarPreference
        android:key="font_size"
        android:title="Font Size"
        android:min="12"
        android:max="32"
        android:defaultValue="14" />

    <EditTextPreference
        android:defaultValue="Default Value"
        android:key="font_size_edittext"
        android:selectAllOnFocus="true"
        android:singleLine="true"
        android:title="A" />
</PreferenceScreen>

implementation 'androidx.preference:preference:1.0.0'