How to save a string in sharedPreferences

问题

I have an application where I need to save a string in a sharedpreferences so that the user has already opened the application once and registered his email he does not have to go through the same screen again and instead go to the home screen directly.

My Class PreferencesHelpers

public class PreferencesHelpers {

private static final String SHARED_PREFS = "sharedPrefs";
private static final String TEXT = "ahhsaushhuuashu"; //I want to save this string

public String text;


public static void saveData(Context context) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();

    editor.putString("", TEXT);

}

public static String loadData(Context context) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
    String text = sharedPreferences.getString("ahhsaushhuuashu", "");
    return text;
   }

}

MyLogic in MainActivity to save and retrieve sharedPreferences value

  if (!preferencesHelpers.loadData(getApplicationContext()).contains("ahhsaushhuuashu")) {
                webView.loadUrl(URL_);
                preferencesHelpers.saveData(getApplicationContext());
            } else {
                switch (urlMessage) {
                    case "REDR":
                        webView.loadUrl(URL + "cira");
                        break;
                    default:
                        webView.loadUrl(URL + "?UDI=" + getInstance().getRegistrationManager().getSystemToken() + "&dev=" + getInstance().getRegistrationManager().getDeviceId() + "&source=app");
                }
            }

I looked for an answer that fit my condition but I did not find and forgive me for my English

回答1:

You need a fixed key to save and read your preference and you forgot to apply the modifications of the SharedPreference.

You need to do like this:

private static final String SHARED_PREFS = "sharedPrefs";
private static final String TEXT = "ahhsaushhuuashu";
private static final String KEY = "myKey";

public static void saveData(Context context) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putString(KEY, TEXT);
    editor.apply();
}

public static String loadData(Context context) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
    String text = sharedPreferences.getString(KEY, "");
    return text;
}

回答2:

As mentioned by others in the comments you need Keys for storing a value, but also I see that you are not saving the value in the saveData method.

You need to type in this line:

editor.apply()

after

editor.putString("", TEXT);

in the saveData method

来源：https://stackoverflow.com/questions/54075490/how-to-save-a-string-in-sharedpreferences

标签

java

android

sharedpreferences