如何将分数保存到SharedPreferences然后更新它？ [英] How to save score to SharedPreferences then update it?

问题描述

我有一个应用程序，它将MainActivity中明星的总收入显示为textview。如果应用程序第一次运行，我想做的是输入0。然后，当我完成一个级别并获得一些星级（如currentScore + 50 = newScore）后，它将使用newScore textView重定向到MainActivity。

I have an app which shows the total earnings of stars in the MainActivity as textview. I want to do is input 0 if the app is run for the first time. Then afterwards as I finish a level and earn some stars (like currentScore + 50 = newScore) it will be redirected to MainActivity with the newScore textView.

这是我的MainActivity，其中textview显示分数

This is my MainActivity where the the textview shows the score

public class MainActivity extends Activity {

  private static TextView txt_stars;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    updateStars();
  }

    public void updateStars() {
    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putInt("Stars", 0);
    editor.commit();
    txt_stars = (TextView) findViewById(R.id.txtStars);
    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        //the key is "Stars" don't forget to type it as you created the Sp
    String stars = String.valueOf(sharedPreferences.getInt("Stars", 0));
    txt_stars.setText(stars);
}
}

对于我读取当前分数的活动，添加50然后更新

And for the activity where I read the current score then add 50 to it then update

public void onClick(DialogInterface dialog, int whichButton) {

     SharedPreferences sharedPreferences = 
     PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
     Integer newstars = sharedPreferences.getInt("Stars", 0);
     Integer totalStars = newstars + 50;
     SharedPreferences.Editor editor = sharedPreferences.edit();
     editor.putInt("Stars", totalStars);
     editor.commit();

  //please help me improve my code here

    Intent nextForm = new Intent(.MainActivity");
    startActivity(nextForm);

  }

还可以在不同的活动中使用SharedPreferences吗？就像我只保存一个分数一样来自ActivityOne，可以在ActivityTwo中阅读吗？

And also can a SharedPreferences be use in different activities? Like I just save a score from ActivityOne and can be read in ActivityTwo?

非常感谢！

推荐答案

好吧，你应该先阅读 SharedPreferences文档 ，然后按照我的步骤使用 SharedPreferences

Well, you should first read the SharedPreferences documentation, and then follow my steps to save values with SharedPreferences

您的 UpdateStars（）方法应如下所示：

public class updateStars() {
txt_stars = (TextView) findViewById(R.id.txtStars);
sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
//the key is "Stars" don't forget to type it as you created the Sp
String stars = String.valueOf(sharedPreferences.getInt("Stars", 0));
txt_stars.setText(stars);
}

每次你想保留用户 Stars 你必须使用 putInt（）：

And everytime you want to keep the users Stars you'll have to use the putInt() :

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt("Stars", YOUR_INT_VALUE); //Here you save the stars of the user
editor.commit();

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