Android应用程序中的计数器按钮与SharedPreferences无法正常工作

Question

我遇到了一个有关保存由Button修改的整数的问题。按下Button时，整数值上升;但是，当我关闭并重新打开应用程序时，整数不会被保存。我将不胜感激任何帮助。

public class MyActivity extends Activity implements View.OnClickListener {

public static final String PREFS_NAME = "MyPrefsFile";

Button btn1;
Button btn2;
Button btn3;
Button btn4;
Button save;
TextView textTitle;
EditText scoreText;
EditText scoreText2;
int counter = 0;

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

    btn1 = (Button) findViewById(R.id.add);
    btn2 = (Button) findViewById((R.id.sub));

    scoreText = (EditText) findViewById(R.id.intro);

    btn1.setOnClickListener(this);
    btn2.setOnClickListener(this);


    final SharedPreferences prefs = PreferenceManager
        .getDefaultSharedPreferences(this);

    scoreText.setText(prefs.getString("autosave" , ""));

    scoreText.addTextChangedListener(new TextWatcher() {

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            // Do nothing

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

            // Do nothing

        }

       @Override
       public void afterTextChanged(Editable s) {

           prefs.edit().putString("autosave", s.toString()).commit();

        }

    });

    @Override
    public void onClick(View v) {

        if (v == btn1) {

            counter++;
            scoreText.setText(Integer.toString(counter));

        } else if (v == btn2) {

        counter--;
        scoreText.setText(Integer.toString(counter));

        }

    }

}

Answer 1

首先，尝试将commit（）行移动到onTextChanged（）回调并添加一个Log.d（）调用以帮助您进行调试。

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {

    Log.d("onTextChanged", s.toString());

    prefs.edit().putString("autosave", s.toString()).commit();

}

修改文本时检查日志以确保触发回调。

如果这不起作用，我建议将commit（）行移动到onClick（）回调。

@Override
public void onClick(View v) {

    if (v == btn1) {

        counter++;
        scoreText.setText(Integer.toString(counter));
        prefs.edit().putString("autosave", scoreText.getText()).commit();


    } else if (v == btn2) {

        counter--;
        scoreText.setText(Integer.toString(counter));
        prefs.edit().putString("autosave", scoreText.getText()).commit();

    }

}