在共享首选项中存储值:

SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sp.edit();
editor.putString("Name","Jayesh");
editor.commit();

从共享首选项中检索值:

SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
String name = sp.getString("Name", "");

简单的方法:

保存:

getPreferences(MODE_PRIVATE).edit().putString("Name of variable",value).commit();

检索:

your_variable = getPreferences(MODE_PRIVATE).getString("Name of variable",default value);

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" />

在任何应用程序中，都有可以通过PreferenceManager实例及其相关方法getDefaultSharedPreferences(Context)访问的默认首选项。

使用SharedPreference实例，可以使用getInt(String key, int defVal)检索任意首选项的int值。在这种情况下，我们更倾向于使用计数器。

在我们的例子中，我们可以使用edit()并使用putInt(String key, int newVal)来修改SharedPreference实例。我们增加了应用程序的计数，这些计数超出了应用程序并相应地显示。

为了进一步演示这一点，再次重新启动应用程序，您将注意到每次重新启动应用程序时计数都会增加。

PreferencesDemo.java

代码:

package org.example.preferences;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.widget.TextView;

public class PreferencesDemo extends Activity {
   /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // Get the app's shared preferences
        SharedPreferences app_preferences = 
        PreferenceManager.getDefaultSharedPreferences(this);

        // Get the value for the run counter
        int counter = app_preferences.getInt("counter", 0);

        // Update the TextView
        TextView text = (TextView) findViewById(R.id.text);
        text.setText("This app has been started " + counter + " times.");

        // Increment the counter
        SharedPreferences.Editor editor = app_preferences.edit();
        editor.putInt("counter", ++counter);
        editor.commit(); // Very important
    }
}

main。xml

代码:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent" >

        <TextView
            android:id="@+id/text"  
            android:layout_width="fill_parent" 
            android:layout_height="wrap_content" 
            android:text="@string/hello" />
</LinearLayout>

如果你正在与团队中的其他开发人员一起开发一个大型应用程序，并打算让所有内容都很好地组织起来，而不是分散的代码或不同的SharedPreferences实例，你可以这样做:

//SharedPreferences manager class
public class SharedPrefs {

    //SharedPreferences file name
    private static String SHARED_PREFS_FILE_NAME = "my_app_shared_prefs";

    //here you can centralize all your shared prefs keys
    public static String KEY_MY_SHARED_BOOLEAN = "my_shared_boolean";
    public static String KEY_MY_SHARED_FOO = "my_shared_foo";

    //get the SharedPreferences object instance
    //create SharedPreferences file if not present


    private static SharedPreferences getPrefs(Context context) {
        return context.getSharedPreferences(SHARED_PREFS_FILE_NAME, Context.MODE_PRIVATE);
    }

    //Save Booleans
    public static void savePref(Context context, String key, boolean value) {
        getPrefs(context).edit().putBoolean(key, value).commit();       
    }

    //Get Booleans
    public static boolean getBoolean(Context context, String key) {
        return getPrefs(context).getBoolean(key, false);
    }

    //Get Booleans if not found return a predefined default value
    public static boolean getBoolean(Context context, String key, boolean defaultValue) {
        return getPrefs(context).getBoolean(key, defaultValue);
    }

    //Strings
    public static void save(Context context, String key, String value) {
        getPrefs(context).edit().putString(key, value).commit();
    }

    public static String getString(Context context, String key) {
        return getPrefs(context).getString(key, "");
    }

    public static String getString(Context context, String key, String defaultValue) {
        return getPrefs(context).getString(key, defaultValue);
    }

    //Integers
    public static void save(Context context, String key, int value) {
        getPrefs(context).edit().putInt(key, value).commit();
    }

    public static int getInt(Context context, String key) {
        return getPrefs(context).getInt(key, 0);
    }

    public static int getInt(Context context, String key, int defaultValue) {
        return getPrefs(context).getInt(key, defaultValue);
    }

    //Floats
    public static void save(Context context, String key, float value) {
        getPrefs(context).edit().putFloat(key, value).commit();
    }

    public static float getFloat(Context context, String key) {
        return getPrefs(context).getFloat(key, 0);
    }

    public static float getFloat(Context context, String key, float defaultValue) {
        return getPrefs(context).getFloat(key, defaultValue);
    }

    //Longs
    public static void save(Context context, String key, long value) {
        getPrefs(context).edit().putLong(key, value).commit();
    }

    public static long getLong(Context context, String key) {
        return getPrefs(context).getLong(key, 0);
    }

    public static long getLong(Context context, String key, long defaultValue) {
        return getPrefs(context).getLong(key, defaultValue);
    }

    //StringSets
    public static void save(Context context, String key, Set<String> value) {
        getPrefs(context).edit().putStringSet(key, value).commit();
    }

    public static Set<String> getStringSet(Context context, String key) {
        return getPrefs(context).getStringSet(key, null);
    }

    public static Set<String> getStringSet(Context context, String key, Set<String> defaultValue) {
        return getPrefs(context).getStringSet(key, defaultValue);
    }
}

在您的活动中，您可以这样保存SharedPreferences

//saving a boolean into prefs
SharedPrefs.savePref(this, SharedPrefs.KEY_MY_SHARED_BOOLEAN, booleanVar);

你可以这样检索你的SharedPreferences

//getting a boolean from prefs
booleanVar = SharedPrefs.getBoolean(this, SharedPrefs.KEY_MY_SHARED_BOOLEAN);

我创建了一个Helper类来简化我的生活。这是一个泛型类，有很多在应用程序中常用的方法，如共享首选项，电子邮件有效性，日期时间格式。在代码中复制这个类，并在任何需要的地方访问它的方法。

 import android.app.AlertDialog;
 import android.app.ProgressDialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.SharedPreferences;
 import android.support.v4.app.FragmentActivity;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.EditText;
 import android.widget.Toast;

 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Random;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;

/**
* Created by Zohaib Hassan on 3/4/2016.
*/
 public class Helper {

private static ProgressDialog pd;

public static void saveData(String key, String value, Context context) {
    SharedPreferences sp = context.getApplicationContext()
            .getSharedPreferences("appData", 0);
    SharedPreferences.Editor editor;
    editor = sp.edit();
    editor.putString(key, value);
    editor.commit();
}

public static void deleteData(String key, Context context){
    SharedPreferences sp = context.getApplicationContext()
            .getSharedPreferences("appData", 0);
    SharedPreferences.Editor editor;
    editor = sp.edit();
    editor.remove(key);
    editor.commit();

}

public static String getSaveData(String key, Context context) {
    SharedPreferences sp = context.getApplicationContext()
            .getSharedPreferences("appData", 0);
    String data = sp.getString(key, "");
    return data;

}




public static long dateToUnix(String dt, String format) {
    SimpleDateFormat formatter;
    Date date = null;
    long unixtime;
    formatter = new SimpleDateFormat(format);
    try {
        date = formatter.parse(dt);
    } catch (Exception ex) {

        ex.printStackTrace();
    }
    unixtime = date.getTime();
    return unixtime;

}

public static String getData(long unixTime, String formate) {

    long unixSeconds = unixTime;
    Date date = new Date(unixSeconds);
    SimpleDateFormat sdf = new SimpleDateFormat(formate);
    String formattedDate = sdf.format(date);
    return formattedDate;
}

public static String getFormattedDate(String date, String currentFormat,
                                      String desiredFormat) {
    return getData(dateToUnix(date, currentFormat), desiredFormat);
}




public static double distance(double lat1, double lon1, double lat2,
                              double lon2, char unit) {
    double theta = lon1 - lon2;
    double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2))
            + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2))
            * Math.cos(deg2rad(theta));
    dist = Math.acos(dist);
    dist = rad2deg(dist);
    dist = dist * 60 * 1.1515;
    if (unit == 'K') {
        dist = dist * 1.609344;
    } else if (unit == 'N') {
        dist = dist * 0.8684;
    }
    return (dist);
}

/* ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: */
/* :: This function converts decimal degrees to radians : */
/* ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: */
private static double deg2rad(double deg) {
    return (deg * Math.PI / 180.0);
}

/* ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: */
/* :: This function converts radians to decimal degrees : */
/* ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: */
private static double rad2deg(double rad) {
    return (rad * 180.0 / Math.PI);
}

public static int getRendNumber() {
    Random r = new Random();
    return r.nextInt(360);
}

public static void hideKeyboard(Context context, EditText editText) {
    InputMethodManager imm = (InputMethodManager) context
            .getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
}

public static void showLoder(Context context, String message) {
    pd = new ProgressDialog(context);

    pd.setCancelable(false);
    pd.setMessage(message);
    pd.show();
}

public static void showLoderImage(Context context, String message) {
    pd = new ProgressDialog(context);
    pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    pd.setCancelable(false);
    pd.setMessage(message);
    pd.show();
}

public static void dismissLoder() {
    pd.dismiss();
}

public static void toast(Context context, String text) {

    Toast.makeText(context, text, Toast.LENGTH_LONG).show();
}
/*
     public static Boolean connection(Context context) {
    ConnectionDetector connection = new ConnectionDetector(context);
    if (!connection.isConnectingToInternet()) {

        Helper.showAlert(context, "No Internet access...!");
        //Helper.toast(context, "No internet access..!");
        return false;
    } else
        return true;
}*/

public static void removeMapFrgment(FragmentActivity fa, int id) {

    android.support.v4.app.Fragment fragment;
    android.support.v4.app.FragmentManager fm;
    android.support.v4.app.FragmentTransaction ft;
    fm = fa.getSupportFragmentManager();
    fragment = fm.findFragmentById(id);
    ft = fa.getSupportFragmentManager().beginTransaction();
    ft.remove(fragment);
    ft.commit();

}

public static AlertDialog showDialog(Context context, String message) {
    AlertDialog.Builder builder = new AlertDialog.Builder(context);
    builder.setMessage(message);

    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int id) {
            // TODO Auto-generated method stub

        }
    });

    return builder.create();
}

public static void showAlert(Context context, String message) {
    AlertDialog.Builder builder = new AlertDialog.Builder(context);
    builder.setTitle("Alert");
    builder.setMessage(message)
            .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    dialog.dismiss();
                }
            }).show();
}

public static boolean isURL(String url) {
    if (url == null)
        return false;

    boolean foundMatch = false;
    try {
        Pattern regex = Pattern
                .compile(
                        "\\b(?:(https?|ftp|file)://|www\\.)?[-A-Z0-9+&#/%?=~_|$!:,.;]*[A-Z0-9+&@#/%=~_|$]\\.[-A-Z0-9+&@#/%?=~_|$!:,.;]*[A-Z0-9+&@#/%=~_|$]",
                        Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE);
        Matcher regexMatcher = regex.matcher(url);
        foundMatch = regexMatcher.matches();
        return foundMatch;
    } catch (PatternSyntaxException ex) {
        // Syntax error in the regular expression
        return false;
    }
}

public static boolean atLeastOneChr(String string) {
    if (string == null)
        return false;

    boolean foundMatch = false;
    try {
        Pattern regex = Pattern.compile("[a-zA-Z0-9]",
                Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE);
        Matcher regexMatcher = regex.matcher(string);
        foundMatch = regexMatcher.matches();
        return foundMatch;
    } catch (PatternSyntaxException ex) {
        // Syntax error in the regular expression
        return false;
    }
}

public static boolean isValidEmail(String email, Context context) {
    String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
    CharSequence inputStr = email;
    Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);
    Matcher matcher = pattern.matcher(inputStr);
    if (matcher.matches()) {
        return true;
    } else {
        // Helper.toast(context, "Email is not valid..!");

        return false;
    }
}

public static boolean isValidUserName(String email, Context context) {
    String expression = "^[0-9a-zA-Z]+$";
    CharSequence inputStr = email;
    Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);
    Matcher matcher = pattern.matcher(inputStr);
    if (matcher.matches()) {
        return true;
    } else {
        Helper.toast(context, "Username is not valid..!");
        return false;
    }
}

public static boolean isValidDateSlash(String inDate) {
    SimpleDateFormat dateFormat = new SimpleDateFormat("dd/mm/yyyy");
    dateFormat.setLenient(false);
    try {
        dateFormat.parse(inDate.trim());
    } catch (ParseException pe) {
        return false;
    }
    return true;
}

public static boolean isValidDateDash(String inDate) {
    SimpleDateFormat dateFormat = new SimpleDateFormat("dd-mm-yyyy");
    dateFormat.setLenient(false);
    try {
        dateFormat.parse(inDate.trim());
    } catch (ParseException pe) {
        return false;
    }
    return true;
}

public static boolean isValidDateDot(String inDate) {
    SimpleDateFormat dateFormat = new SimpleDateFormat("dd.mm.yyyy");
    dateFormat.setLenient(false);
    try {
        dateFormat.parse(inDate.trim());
    } catch (ParseException pe) {
        return false;
    }
    return true;
}

}