MasterSwitchPreference的使用

com.android.settings.widget.MasterSwitchPreference

首先 和 SwitchPreference的区别是：switch和preference 事件分离

MasterSwitchPreference

SwitchPreference

使用

<com.android.settings.widget.MasterSwitchPreference
        android:order="90"
        android:key="app_lock_settings"
        android:title="@string/app_lock_title"
        settings:controller="com.android.settings.security.AppLockPreferenceController"/>

代码 

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.settings.security;
import android.content.Context;
import android.provider.Settings;
import android.app.Activity;
import com.android.settings.R;
import com.android.settings.core.BasePreferenceController;
import androidx.preference.Preference;
import androidx.preference.SwitchPreference;
import android.util.Log;
import java.util.Arrays;
import java.util.List;
import android.text.TextUtils;
import java.util.ArrayList;
import android.view.LayoutInflater;
import android.widget.EditText;
import android.app..CustomerManager;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import android.widget.Toast;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.provider.SearchIndexableResource;
import android.provider.Settings;
import android.widget.Switch;
import android.util.Log;
import androidx.appcompat.app.AlertDialog;
import android.view.View;
import android.widget.TextView;
import android.widget.Button;
import android.widget.LinearLayout;
import android.view.Gravity;
import androidx.preference.PreferenceScreen;
import android.os.SystemProperties;
import com.android.settings.widget.MasterSwitchPreference;
public class AppLockPreferenceController extends BasePreferenceController implements Preference.OnPreferenceChangeListener,Preference.OnPreferenceClickListener{
    private static final String KEY_APP_LOCK = "app_lock_settings";
    public static final String _APP_LOCK = "_app_lock";
    public static final String _SETTINGS_APP_LOCK = "persist.sys.settings.lock";
    private CustomerManager mCustomerManager;
    String oldPassword;
    EditText old_edit_text;
    EditText new_edit_text;
    TextView tip;
    public static final int TYPE_TIP = 0;
    public static final int TYPE_PASSWORD = 1;
    MasterSwitchPreference mPreference;
    public AppLockPreferenceController(Context context) {
        super(context, KEY_APP_LOCK);
        mCustomerManager = (CustomerManager) mContext.getSystemService("_customer");
    }
    @Override
    public int getAvailabilityStatus() {
        return AVAILABLE;
    }
    @Override
    public CharSequence getSummary() {
        return SystemProperties.get(_SETTINGS_APP_LOCK, "0").equals("1")
                ? mContext.getText(R.string.switch_on_text)
                : mContext.getText(R.string.switch_off_text);
    }
    
    @Override
    public void displayPreference(PreferenceScreen screen) {
        super.displayPreference(screen);
        mPreference = screen.findPreference(KEY_APP_LOCK);
        mPreference.setOnPreferenceClickListener(this);
        mPreference.setChecked(SystemProperties.get(_SETTINGS_APP_LOCK, "0").equals("1"));
    }
    
    @Override
    public boolean onPreferenceClick(Preference preference) {
        showCustomizeDialog(TYPE_PASSWORD);
        return true;
    }
    
    @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {
        boolean result = true;
        if (!preference.getKey().equals(KEY_APP_LOCK)) {
            return false;
        }
        mPreference = (MasterSwitchPreference)preference;
        boolean setting = (Boolean)newValue;
        if (setting) {
            showCustomizeDialog(TYPE_PASSWORD);
        } else {
            showCustomizeDialog(TYPE_TIP);
        }
        return true;
    }
    
    
}