java - Android 开发...应用程序结构新手

Question

我正在实现一个 Android 应用程序。用户将选择一个称为距离的特定参数:

1- kilometers;
2- miles.

因此应用程序将保存此响应以供将来使用。

我该如何实现它？我必须创建原始资源还是必须使用 strings.xml？你能解释一下这种情况下的正确结构吗？

Answer 1

您可以使用SharedPreferences保存它。

引用:

The SharedPreferences class provides a general framework that allows you to save and retrieve persistent key-value pairs of primitive data types. You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings. This data will persist across user sessions (even if your application is killed).

To get a SharedPreferences object for your application, use one of two methods:

getSharedPreferences() - Use this if you need multiple preferences files identified by name, which you specify with the first parameter. getPreferences() - Use this if you need only one preferences file for your Activity. Because this will be the only preferences file for your Activity, you don't supply a name. To write values:

Call edit() to get a SharedPreferences.Editor. Add values with methods such as putBoolean() and putString(). Commit the new values with commit() To read values, use SharedPreferences methods such as getBoolean() and getString().

下面是在计算器中保存静音按键模式首选项的示例:

public class Calc extends Activity {
    public static final String PREFS_NAME = "MyPrefsFile";

    @Override
    protected void onCreate(Bundle state){
       super.onCreate(state);
       . . .

       // Restore preferences
       SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
       boolean silent = settings.getBoolean("silentMode", false);
       setSilent(silent);
    }

    @Override
    protected void onStop(){
       super.onStop();

      // We need an Editor object to make preference changes.
      // All objects are from android.context.Context
      SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
      SharedPreferences.Editor editor = settings.edit();
      editor.putBoolean("silentMode", mSilentMode);

      // Commit the edits!
      editor.commit();
    }
}