Question

I save a user’s username and passwords the first time he opens the app and store it in a SharedPreferences object. I check for the data the second time he enters and if its not null, then I got into the app. Here is how I’m doing this:

private SharedPreferences dhj;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    dhj = this.getSharedPreferences("DHJ", MODE_WORLD_READABLE);
    if(dhj.getString("username", null) != null) {
        setContentView(R.layout.main);
            // do some stuff...
    }
    else {
            setContentView(R.layout.login);
            username = (EditText) findViewById(R.id.username);
            password = (EditText) findViewById(R.id.password);
                    loginButton = (Button) findViewById(R.id.loginButton);

            loginButton.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    SharedPreferences.Editor dhjEditor = dhj.edit();
                    dhjEditor.putString("username", username.getText().toString());
                    dhjEditor.putString("password", password.getText().toString());
                    setContentView(R.layout.main);
                }
            }); 
                    // do some other stuff...
    }
}

But each time I open the app, I am being asked to enter the username and password.
What am I doing wrong? How can I achieve the desired functionality?
Thank you.

Answer 1

You need to call the Editor’s commit method after making any change to preferences. This will save the preferences file:

SharedPreferences.Editor dhjEditor = dhj.edit();
dhjEditor.putString("username", username.getText().toString());
dhjEditor.putString("password", password.getText().toString());
dhjEditor.commit();