3.7

我见周四多妩媚，料周四见我应如是

学习内容：

package com.dongnaoedu.chapter06.util;

import android.content.Context;

import android.content.SharedPreferences;

public class SharedUtil {

    private static SharedUtil mUtil;

    private SharedPreferences preferences;

    public static SharedUtil getInstance(Context ctx) {

        if (mUtil == null) {

            mUtil = new SharedUtil();

            mUtil.preferences = ctx.getSharedPreferences("shopping", Context.MODE_PRIVATE);

        }

        return mUtil;

    }

    public void writeBoolean(String key, boolean value) {

        SharedPreferences.Editor editor = preferences.edit();

        editor.putBoolean(key, value);

        editor.commit();

    }

    public boolean readBoolean(String key, boolean defaultValue) {

        return preferences.getBoolean(key, defaultValue);

    }

}