Android使用SharedPreference存储数据

SharedPreference存储数据和文件存储更加方便的一点是可以按照一定的数据类型进行存储，同时取数据时也能够获取到相应的数据类型。它是按照map的方式来存储和读取数据的。

MainActivity.java

package org.elvalad.sharedpreferencetest;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    private Button saveButton;
    private Button restoreButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        saveButton = (Button) findViewById(R.id.save_data);
        saveButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPreferences.Editor editor = getSharedPreferences("data", MODE_PRIVATE).edit();
                editor.putString("name", "elvald");
                editor.putInt("age", 25);
                editor.putBoolean("married", true);
                editor.commit();
            }
        });

        restoreButton = (Button) findViewById(R.id.restore_data);
        restoreButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPreferences pref = getSharedPreferences("data", MODE_PRIVATE);
                String name = pref.getString("name", "");
                int age = pref.getInt("age", 0);
                Boolean married = pref.getBoolean("married", false);
                Log.d("MainActivity", "name is " + name);
                Log.d("MainActivity", "age is " + age);
                Log.d("MainActivity", "married is " + married);
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <Button
        android:id="@+id/save_data"
        android:text="Save_data"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

   <Button
       android:id="@+id/restore_data"
       android:text="Restore_data"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content" />

</LinearLayout>