最好的实践

创建命名为PreferenceManager的接口:

// Interface to save values in shared preferences and also for retrieve values from shared preferences
public interface PreferenceManager {

    SharedPreferences getPreferences();
    Editor editPreferences();

    void setString(String key, String value);
    String getString(String key);

    void setBoolean(String key, boolean value);
    boolean getBoolean(String key);

    void setInteger(String key, int value);
    int getInteger(String key);

    void setFloat(String key, float value);
    float getFloat(String key);

}

如何使用活动/片段:

public class HomeActivity extends AppCompatActivity implements PreferenceManager{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout_activity_home);
    }

    @Override
    public SharedPreferences getPreferences(){
        return getSharedPreferences("SP_TITLE", Context.MODE_PRIVATE);
    }

    @Override
    public SharedPreferences.Editor editPreferences(){
        return getPreferences().edit();
    }

    @Override
    public void setString(String key, String value) {
        editPreferences().putString(key, value).commit();
    }

    @Override
    public String getString(String key) {
        return getPreferences().getString(key, "");
    }

    @Override
    public void setBoolean(String key, boolean value) {
        editPreferences().putBoolean(key, value).commit();
    }

    @Override
    public boolean getBoolean(String key) {
        return  getPreferences().getBoolean(key, false);
    }

    @Override
    public void setInteger(String key, int value) {
        editPreferences().putInt(key, value).commit();
    }

    @Override
    public int getInteger(String key) {
        return getPreferences().getInt(key, 0);
    }

    @Override
    public void setFloat(String key, float value) {
        editPreferences().putFloat(key, value).commit();
    }

    @Override
    public float getFloat(String key) {
        return getPreferences().getFloat(key, 0);
    }
}

注意:用SP_TITLE替换你的SharedPreference键。

例子:

存储字符串在shareperence:

setString("my_key", "my_value");

从shareperence获取字符串:

String strValue = getString("my_key");

希望这对你有所帮助。

我想在这里补充一点，当使用SharedPreferences时，这个问题的大多数代码片段都有类似MODE_PRIVATE的东西。MODE_PRIVATE意味着无论您写入这个共享首选项的是什么，都只能由您的应用程序读取。

Whatever key you pass to getSharedPreferences() method, android creates a file with that name and stores the preference data into it. Also remember that getSharedPreferences() is supposed to be used when you intend to have multiple preference files for your application. If you intend to use single preference file and store all key-value pairs into it then use the getSharedPreference() method. Its weird why everyone (including myself) simply uses getSharedPreferences() flavor without even understanding the difference between the above two.

下面的视频教程应该会有所帮助 https://www.youtube.com/watch?v=2PcAQ1NBy98

简单和无麻烦::"Android-SharedPreferences-Helper"库

迟到总比不到好:我创建了“Android-SharedPreferences-Helper”库来帮助降低使用SharedPreferences的复杂性和工作量。它还提供了一些扩展功能。它提供的一些东西如下:

一行初始化和设置 轻松选择是使用默认首选项还是自定义首选项文件 每种数据类型的预定义(默认数据类型)和自定义(您可以选择的)默认值 能力设置不同的默认值为单一使用，只是一个额外的参数 你可以注册和取消注册OnSharedPreferenceChangeListener，因为你做的默认类

dependencies {
    ...
    ...
    compile(group: 'com.viralypatel.sharedpreferenceshelper', name: 'library', version: '1.1.0', ext: 'aar')
}

SharedPreferencesHelper对象的声明:(建议在类中 级)

SharedPreferencesHelper sph; 

SharedPreferencesHelper对象的实例化:(建议在 onCreate()方法)

// use one of the following ways to instantiate
sph = new SharedPreferencesHelper(this); //this will use default shared preferences
sph = new SharedPreferencesHelper(this, "myappprefs"); // this will create a named shared preference file
sph = new SharedPreferencesHelper(this, "myappprefs", 0); // this will allow you to specify a mode

将价值观融入到共同的偏好中

非常简单!不像默认的方式(当使用SharedPreferences类时)，你不需要调用.edit()和.commit()。

sph.putBoolean("boolKey", true);
sph.putInt("intKey", 123);
sph.putString("stringKey", "string value");
sph.putLong("longKey", 456876451);
sph.putFloat("floatKey", 1.51f);

// putStringSet is supported only for android versions above HONEYCOMB
Set name = new HashSet();
name.add("Viral");
name.add("Patel");
sph.putStringSet("name", name);

就是这样!您的值存储在共享首选项中。

从共享首选项中获取值

同样，这只是一个使用键名的简单方法调用。

sph.getBoolean("boolKey");
sph.getInt("intKey");
sph.getString("stringKey");
sph.getLong("longKey");
sph.getFloat("floatKey");

// getStringSet is supported only for android versions above HONEYCOMB
sph.getStringSet("name");

它还有很多其他扩展功能

在GitHub知识库页面上查看扩展功能的详细信息，使用和安装说明等。

我为sharedpreferences写了一个helper类:

import android.content.Context;
import android.content.SharedPreferences;

/**
 * Created by mete_ on 23.12.2016.
 */
public class HelperSharedPref {

Context mContext;

public HelperSharedPref(Context mContext) {
    this.mContext = mContext;
}

/**
 *
 * @param key Constant RC
 * @param value Only String, Integer, Long, Float, Boolean types
 */
public void saveToSharedPref(String key, Object value) throws Exception {
    SharedPreferences.Editor editor = mContext.getSharedPreferences(key, Context.MODE_PRIVATE).edit();
    if (value instanceof String) {
        editor.putString(key, (String) value);
    } else if (value instanceof Integer) {
        editor.putInt(key, (Integer) value);
    } else if (value instanceof Long) {
        editor.putLong(key, (Long) value);
    } else if (value instanceof Float) {
        editor.putFloat(key, (Float) value);
    } else if (value instanceof Boolean) {
        editor.putBoolean(key, (Boolean) value);
    } else {
        throw new Exception("Unacceptable object type");
    }

    editor.commit();
}

/**
 * Return String
 * @param key
 * @return null default is null
 */
public String loadStringFromSharedPref(String key) throws Exception {
    SharedPreferences prefs = mContext.getSharedPreferences(key, Context.MODE_PRIVATE);
    String restoredText = prefs.getString(key, null);

    return restoredText;
}

/**
 * Return int
 * @param key
 * @return null default is -1
 */
public Integer loadIntegerFromSharedPref(String key) throws Exception {
    SharedPreferences prefs = mContext.getSharedPreferences(key, Context.MODE_PRIVATE);
    Integer restoredText = prefs.getInt(key, -1);

    return restoredText;
}

/**
 * Return float
 * @param key
 * @return null default is -1
 */
public Float loadFloatFromSharedPref(String key) throws Exception {
    SharedPreferences prefs = mContext.getSharedPreferences(key, Context.MODE_PRIVATE);
    Float restoredText = prefs.getFloat(key, -1);

    return restoredText;
}

/**
 * Return long
 * @param key
 * @return null default is -1
 */
public Long loadLongFromSharedPref(String key) throws Exception {
    SharedPreferences prefs = mContext.getSharedPreferences(key, Context.MODE_PRIVATE);
    Long restoredText = prefs.getLong(key, -1);

    return restoredText;
}

/**
 * Return boolean
 * @param key
 * @return null default is false
 */
public Boolean loadBooleanFromSharedPref(String key) throws Exception {
    SharedPreferences prefs = mContext.getSharedPreferences(key, Context.MODE_PRIVATE);
    Boolean restoredText = prefs.getBoolean(key, false);

    return restoredText;
}

}

以函数的方式存储和检索全局变量。 要测试，请确保页面上有Textview项，取消代码中的两行注释并运行。然后再次注释这两行，然后运行。 这里TextView的id是用户名和密码。

在你想要使用它的每个Class中，在最后添加这两个例程。 我想这个例行程序是全球例行程序，但不知道如何。这个作品。

这些变量随处可见。 它将变量存储在“MyFile”中。你可以按自己的方式改变。

你称之为使用

 storeSession("username","frans");
 storeSession("password","!2#4%");***

变量username将用“frans”填充，密码为“!2#4%”。即使在重新启动后，它们仍然可用。

你用

 password.setText(getSession(("password")));
 usernames.setText(getSession(("username")));

下面是我的grid.java的全部代码

    package nl.yentel.yenteldb2;
    import android.content.SharedPreferences;
    import android.os.Bundle;
    import android.support.design.widget.FloatingActionButton;
    import android.support.design.widget.Snackbar;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;
    import android.view.View;
    import android.widget.EditText;
    import android.widget.TextView;

    public class Grid extends AppCompatActivity {
    private TextView usernames;
    private TextView password;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_grid);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

      ***//  storeSession("username","frans.eilering@gmail.com");
        //storeSession("password","mijn wachtwoord");***
        password = (TextView) findViewById(R.id.password);
        password.setText(getSession(("password")));
        usernames=(TextView) findViewById(R.id.username);
        usernames.setText(getSession(("username")));
    }

    public void storeSession(String key, String waarde) { 
        SharedPreferences pref = getApplicationContext().getSharedPreferences("MyFile", MODE_PRIVATE);
        SharedPreferences.Editor editor = pref.edit();
        editor.putString(key, waarde);
        editor.commit();
    }

    public String getSession(String key) {
//http://androidexample.com/Android_SharedPreferences_Basics/index.php?view=article_discription&aid=126&aaid=146
        SharedPreferences pref = getApplicationContext().getSharedPreferences("MyFile", MODE_PRIVATE);
        SharedPreferences.Editor editor = pref.edit();
        String output = pref.getString(key, null);
        return output;
    }

    }

下面是textview项

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="usernames"
    android:id="@+id/username"
    android:layout_below="@+id/textView"
    android:layout_alignParentStart="true"
    android:layout_marginTop="39dp"
    android:hint="hier komt de username" />

 <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="password"
    android:id="@+id/password"
    android:layout_below="@+id/user"
    android:layout_alignParentStart="true"
    android:hint="hier komt het wachtwoord" />

在共享首选项中存储值:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("Name","Harneet");
editor.apply();

从共享首选项中检索值:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
String name = preferences.getString("Name", "");
if(!name.equalsIgnoreCase(""))
{
    name = name + "  Sethi";  /* Edit the value here*/
}