Question

我正在使用共享偏好来存储我的玩家的高分。高分功能有效，高分可以保存，但是当我对代码进行更改时，玩家的高分将重置为0.我很担心这个，因为如果我将来需要更新，它将重新启动我的玩家分数。

public void highscoreSaver() {

    if(finalScore > SharedPrefManager.getHighScore()) {
        SharedPrefManager.SetHighScore(finalScore);             
        SharedPrefManager.StoreToPref();
        }

}

SharedPrefManager.java：

package com.divergent.thumbler;

import android.content.Context;
import android.content.SharedPreferences;

// all methods are static , so we can call from any where in the code
//all member variables are private, so that we can save load with our own fun only
public class SharedPrefManager {
//this is your shared preference file name, in which we will save data
public static final String MY_EMP_PREFS = "MySharedPref";  

//saving the context, so that we can call all 
//shared pref methods from non activity classes. 
//because getSharedPreferences required the context.
//but in activity class we can call without this context
private static Context     mContext; 

// will get user input in below variables, then will store in to shared pref
private static int         HighScore;

public static void Init(Context context)
{
    mContext         = context;
}
public static void LoadFromPref()
{
    SharedPreferences settings     = mContext.getSharedPreferences(MY_EMP_PREFS, 0);
    // Note here the 2nd parameter 0 is the default parameter for private access,
    //Operating mode. Use 0 or MODE_PRIVATE for the default operation,
    settings.getInt("HighScore", HighScore);

}
public static void StoreToPref()
{
    // get the existing preference file
    SharedPreferences settings = mContext.getSharedPreferences(MY_EMP_PREFS, 0); 
    //need an editor to edit and save values
    SharedPreferences.Editor editor = settings.edit();

    editor.putInt("HighScore", HighScore); // Age is the key and mAge is holding the value

    //final step to commit (save)the changes in to the shared pref
    editor.commit(); 
}

public static void DeleteSingleEntryFromPref(String keyName)
{
    SharedPreferences settings = mContext.getSharedPreferences(MY_EMP_PREFS, 0); 
    //need an editor to edit and save values
    SharedPreferences.Editor editor = settings.edit();
    editor.remove(keyName);
    editor.commit();
}

public static void DeleteAllEntriesFromPref()
{
    SharedPreferences settings = mContext.getSharedPreferences(MY_EMP_PREFS, 0); 
    //need an editor to edit and save values
    SharedPreferences.Editor editor = settings.edit();
    editor.clear();
    editor.commit();
}


public static void SetHighScore(int score)
{
    HighScore = score;
}

public static int getHighScore()
{
    return HighScore ;
}
}

Answer 1

您永远不会将HighScore整数设置为值。我想也许你认为这条线正在做一些与实际不同的事情：

settings.getInt("HighScore", HighScore);

这将调用getInt函数，该函数返回在第一个参数中具有键的值。如果该值不存在于共享首选项中，则会返回HighScore。您可能想要的是：

HighScore = settings.getInt("HighScore", 0)

这会将HighScore设置为＆＃34; HighScore＆＃34;下的设置中的值。如果没有值，那么它将返回0.

如果您打算致电LoadFromPref()，请务必致电getHighScore()！

Answer 2

SharedPreferences用于存储应用程序级别值。每当您对代码进行更改并再次运行应用程序时，它都会创建共享首选项作为新文件＆amp;以前的所有数据都会重置

如果您在进行一些代码更改并重新运行应用程序后仍希望得分。最好将分数存储在文件或数据库中，如果设备中已存在，则避免创建文件或副本数据库。因此，您始终可以随时获取该数据。您也可以使用内容提供商。

Answer 3

这是我为共享的prefrences写的一个类。它在我正在进行的简单游戏中运行良好。您只需在活动中使用此单例，您需要设置/获取游戏的高分。我将它用于默认的共享优先级，但如果需要，它也可以用于多个优先级。

 /**
  * 
  *         This class is used for reading / writing data to a single prefrences
  *         file.
  * 
  *         Simply use setHighScore and getHighScore to get the score from a
  *         single prefrences file
  * 
  */
public enum SharedPrefrencesUtil {

UTIL;

private final String HIGH_SCORE = "HighScore";

/**
 * Gets a single shared prefrences file
 */
public SharedPreferences getDefaultSharedPreference(Activity activity) {
    return activity.getPreferences(Context.MODE_PRIVATE);
}

/**
 * Gets a specific shared preferences file if there are multiples in the application 
 */
public SharedPreferences getSharedPreferences(String preferenceFileName,
        Context context) {

    return context.getSharedPreferences(preferenceFileName, Context.MODE_PRIVATE);

}

/**
 * Sets a score into a the default prefrences file
 */
public void setScore(Activity activity, int score){
    activity.getPreferences(Context.MODE_PRIVATE).edit().putInt(HIGH_SCORE, score).commit();
}

/**
 * Gets the score from the default prefrences file
 */
public int getHighScore(Activity activity) {
    return activity.getPreferences(Context.MODE_PRIVATE).getInt(HIGH_SCORE, 0);

}

}

编译代码时不保存共享首选项

3 个答案: