Java Android studio，关闭应用程序时记住输入

我们这学期一直在做这个啤酒应用程序，你可以添加饮料作为标准，然后按下按钮，它会计算啤酒并为你添加一笔金额

我们遇到的一个问题是，当我们按下按钮时，计数被汇总。当我们在模拟器上关闭应用程序时，它不会记住输入。有办法解决这个问题吗

基本上，我们希望它记住Msum和Mcount，即使在应用程序关闭或重新打开之后

代码是：

一个文件

public class ResourceManager {
    private static ResourceManager singleton = new ResourceManager();
    private ResourceManager() {}

    public static ResourceManager getInstance() {
        return singleton;
    }

    protected static int cost_beer = 0;
    protected static int cost_drink = 0;
    protected static int count = 0;
    protected static int sum = 0;
}

主文件：

countButton.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        ResourceManager.getInstance().count++;
        ResourceManager.getInstance().sum += ResourceManager.getInstance().cost_beer;
        countTextView.setText("Du har drukket " + ResourceManager.getInstance().count + " enheter!");
        sumTextView.setText("Sum:" + ResourceManager.getInstance().sum + "!");
    }
});
drinkButton.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        ResourceManager.getInstance().count++;
        ResourceManager.getInstance().sum += ResourceManager.getInstance().cost_drink;
        countTextView.setText("You have been drinking " + ResourceManager.getInstance().count + " units!");
        sumTextView.setText("Sum:" + ResourceManager.getInstance().sum + "!");
    }
});
resetButton.setOnClickListener(new View.OnClickListener() {
    public void onClick (View view) {
        ResourceManager.getInstance().sum = 0;
        ResourceManager.getInstance().count = 0;
        countTextView.setText("You have been drinking " + ResourceManager.getInstance().count + " units!");
        sumTextView.setText("Sum:" + ResourceManager.getInstance().sum + "!");
    }
});

---

查看

SharedReferences

。这可能对你有帮助。它以键值对的形式存储数据

有关示例，请参见StackOverflow链接

要保存数据，请执行以下操作：

// MY_PREFS_NAME - a static String variable like:  
//public static final String MY_PREFS_NAME = "MyPrefsFile"; 
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME,  MODE_PRIVATE).edit();
editor.putString("name", "Elena");
editor.putInt("idName", 12);
editor.commit();

要检索：

SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE); 
String restoredText = prefs.getString("text", null);
if (restoredText != null) {
  String name = prefs.getString("name", "No name defined");//"No name defined" is the default value.
  int idName = prefs.getInt("idName", 0); //0 is the default value.
} 

以下是官方文件：

---

另外还有一个示例，帮助您查看

共享参考资料
。这可能对你有帮助。它以键值对的形式存储数据

有关示例，请参见StackOverflow链接

要保存数据，请执行以下操作：

// MY_PREFS_NAME - a static String variable like:  
//public static final String MY_PREFS_NAME = "MyPrefsFile"; 
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME,  MODE_PRIVATE).edit();
editor.putString("name", "Elena");
editor.putInt("idName", 12);
editor.commit();

要检索：

SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE); 
String restoredText = prefs.getString("text", null);
if (restoredText != null) {
  String name = prefs.getString("name", "No name defined");//"No name defined" is the default value.
  int idName = prefs.getInt("idName", 0); //0 is the default value.
} 

以下是官方文件：

另一个示例帮助您使用SharedReferences。使用SharedReferences。