Android SharedPreferences Example

问题

I'm trying to learn SharedPreferences, but I'm getting an error.

My layout has one button that reeacts to the method doThis

This is my java:

package com.example.sharedprefs;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {
    int i = 0;

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

    }

    public void doThis (View view){
        i++;
        SharedPreferences sharedPref = getSharedPreferences("FileName",MODE_PRIVATE);
        SharedPreferences.Editor prefEditor = sharedPref.edit();
        prefEditor.putInt("userChoice",i);
        prefEditor.commit();
        int number = sharedPref.getInt("userChoice", 0);
        Toast.makeText(getApplicationContext(), number, Toast.LENGTH_LONG).show();
    }

}

Only thing I can pinpoint in logcat is 10-15 19:28:17.707: E/AndroidRuntime(16657): Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x1

回答1:

Your toast is incorrect. You are passing a number into the toast hoping that it will give a string, instead is thinks it should be looking up a string resource value. Try:

Toast.makeText(getContext(), number + "" , Toast.LENGTH_LONG).show();

Edit, other than that, your code is fine.

回答2:

You can't make a integer type to Toast message.

you can only put String type to the message parameter to Toast.makeText method.

as for solution, you can try these

Toast.makeText(getApplicationContext(), Integer.toString(number), Toast.LENGTH_LONG).show();

Toast.makeText(getApplicationContext(), ""+number, Toast.LENGTH_LONG).show();

and yes, your sharedpreference usage is perfectly fine.

回答3:

The problem here is you are using an integer value as the Toast string. You have to do the following.

String.valueOf(number);

Integer.toString(number);

Your sharedpreferences part is ok. But for more info about SharedPreferences you can visit this post. Android SharedPreferences Example

来源：https://stackoverflow.com/questions/12905456/android-sharedpreferences-example

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java

android

sharedpreferences