为自定义首选项夸大类别的错误

Question

我正在尝试使用一些由hidron编写的首选项类。我将SpinnerPrefence类添加到preference.xml，但是我运行该应用程序，它给了我InflateException错误。问题是为什么我会收到此错误！我在xml文件中检查了程序包名称，可以。我进行了搜索以找到解决方案，并在SpinnerPreference类中添加了完整的构造函数，但找不到问题。有什么解决办法吗？

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.payachip.automatedgreenhouse, PID: 14777
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.payachip.automatedgreenhouse/com.payachip.automatedgreenhouse.Activities.ActivitySettings}: android.view.InflateException: Binary XML file line #12: Error inflating class com.payachip.automatedgreenhouse.Preferences.SpinnerPreference
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
                      at android.app.ActivityThread.-wrap11(Unknown Source:0)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
                      at android.os.Handler.dispatchMessage(Handler.java:106)
                      at android.os.Looper.loop(Looper.java:164)
                      at android.app.ActivityThread.main(ActivityThread.java:6494)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
                   Caused by: android.view.InflateException: Binary XML file line #12: Error inflating class com.payachip.automatedgreenhouse.Preferences.SpinnerPreference
                      at android.support.v7.preference.PreferenceInflater.createItem(PreferenceInflater.java:258)
                      at android.support.v7.preference.PreferenceInflater.createItemFromTag(PreferenceInflater.java:287)
                      at android.support.v7.preference.PreferenceInflater.rInflate(PreferenceInflater.java:354)
                      at android.support.v7.preference.PreferenceInflater.rInflate(PreferenceInflater.java:356)
                      at android.support.v7.preference.PreferenceInflater.inflate(PreferenceInflater.java:162)
                      at android.support.v7.preference.PreferenceInflater.inflate(PreferenceInflater.java:112)
                      at android.support.v7.preference.PreferenceManager.inflateFromResource(PreferenceManager.java:137)
                      at android.support.v7.preference.PreferenceFragmentCompat.addPreferencesFromResource(PreferenceFragmentCompat.java:432)
                      at com.payachip.automatedgreenhouse.Fragments.FragmentPreference.onCreatePreferences(FragmentPreference.java:35)
                      at android.support.v7.preference.PreferenceFragmentCompat.onCreate(PreferenceFragmentCompat.java:224)
                      at com.payachip.automatedgreenhouse.Fragments.FragmentPreference.onCreate(FragmentPreference.java:29)
                      at android.support.v4.app.Fragment.performCreate(Fragment.java:2331)
                      at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1386)
                      at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1188)
                      at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:1071)
                      at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:115)
                      at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2380)
                      at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2338)
                      at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2245)
                      at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3248)
                      at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:3200)
                      at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:195)
                      at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:597)
                      at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:177)
                      at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1334)
                      at android.app.Activity.performStart(Activity.java:7029)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2741)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
                      at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
                      at android.os.Handler.dispatchMessage(Handler.java:106) 
                      at android.os.Looper.loop(Looper.java:164) 
                      at android.app.ActivityThread.main(ActivityThread.java:6494) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
                   Caused by: java.lang.InstantiationException: Can't instantiate abstract class com.payachip.automatedgreenhouse.Preferences.SpinnerPreference
                      at java.lang.reflect.Constructor.newInstance0(Native Method)
                      at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
                      at android.support.v7.preference.PreferenceInflater.createItem(PreferenceInflater.java:251)
                        ... 35 more

SpinnerPreference.java

package com.payachip.automatedgreenhouse.Preferences;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.support.v7.preference.Preference;
import android.support.v7.preference.PreferenceViewHolder;
import android.util.AttributeSet;

import com.payachip.automatedgreenhouse.R;

public abstract class SpinnerPreference extends Preference {

    protected String[] mEntries = new String[0];
    protected String[] mEntryValues = new String[0];
    private int mSelection = 0;

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public SpinnerPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs);
    }

    public SpinnerPreference(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    public SpinnerPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public SpinnerPreference(Context context) {
        super(context);
        init(context, null);
    }

    private void init(Context context, AttributeSet attrs) {
        setWidgetLayoutResource(R.layout.preference_spinner);
        TypedArray ta;
        if(attrs != null){
            ta = context.obtainStyledAttributes(attrs, R.styleable.SpinnerPreference);
        }else {
            ta = context.obtainStyledAttributes(R.styleable.SpinnerPreference);
        }
        int entriesResId = ta.getResourceId(R.styleable.SpinnerPreference_entries, 0);
        if (entriesResId != 0) {
            mEntries = context.getResources().getStringArray(entriesResId);
        }
        int valuesResId = ta.getResourceId(R.styleable.SpinnerPreference_entryValues, 0);
        if (valuesResId != 0) {
            mEntryValues = context.getResources().getStringArray(valuesResId);
        }
        ta.recycle();
    }
}

这是我的preference.xml

<android.support.v7.preference.PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.preference.PreferenceCategory
        android:title="General">

        <com.payachip.automatedgreenhouse.Preferences.SpinnerPreference
            android:key="LANGUAGE_KEY"
            android:title="@string/pref_language_title"
            android:defaultValue="0"
            app:entries="@array/pref_language_type_options"
            app:entryValues="@array/pref_language_type_values" />

    </android.support.v7.preference.PreferenceCategory>
</android.support.v7.preference.PreferenceScreen>

ActivitySetting.java

public class ActivitySettings extends AppCompatActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_setting);
        if (savedInstanceState == null) {
            // Display the fragment as the main content.
            FragmentPreference fragmentPreference = FragmentPreference.newInstance();
            fragmentPreference.setArguments(this.getIntent().getExtras());
            this.getSupportFragmentManager().beginTransaction().replace(R.id.content, fragmentPreference).commit();
        }
    }
}

FragmentPreference.java

public class FragmentPreference  extends PreferenceFragmentCompat {

    public static FragmentPreference newInstance(){
        FragmentPreference fr = new FragmentPreference();
        return fr;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public void onCreatePreferences(Bundle bundle, String s) {
        addPreferencesFromResource(R.xml.preference);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }
}

谢谢。