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;
}

}

写:

SharedPreferences preferences = getSharedPreferences("AUTHENTICATION_FILE_NAME", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("Authentication_Id",userid.getText().toString());
editor.putString("Authentication_Password",password.getText().toString());
editor.putString("Authentication_Status","true");
editor.apply();

阅读:

SharedPreferences prfs = getSharedPreferences("AUTHENTICATION_FILE_NAME", Context.MODE_PRIVATE);
String Astatus = prfs.getString("Authentication_Status", "");

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。

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" />

SharedPreferences的基本思想是将内容存储在XML文件中。

Declare your xml file path.(if you don't have this file, Android will create it. If you have this file, Android will access it.) SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE); Write value to Shared Preferences prefs.edit().putLong("preference_file_key", 1010101).apply(); the preference_file_key is the name of shared preference files. And the 1010101 is the value you need to store. apply() at last is to save the changes. If you get error from apply(), change it to commit(). So this alternative sentence is prefs.edit().putLong("preference_file_key", 1010101).commit(); Read from Shared Preferences SharedPreferences sp = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE); long lsp = sp.getLong("preference_file_key", -1); lsp will be -1 if preference_file_key has no value. If 'preference_file_key' has a value, it will return the value of this.

整个代码是

    SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);    // Declare xml file
    prefs.edit().putLong("preference_file_key", 1010101).apply();    // Write the value to key.

阅读的代码是

    SharedPreferences sf = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);    // Declare xml file
    long lsp = sp.getLong("preference_file_key", -1);    // Read the key and store in lsp

使用这个例子简单明了

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.sairamkrishna.myapplication" >

   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" >

      <activity
         android:name=".MainActivity"
         android:label="@string/app_name" >

         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>

      </activity>

   </application>
</manifest>

public class MainActivity extends AppCompatActivity {
   EditText ed1,ed2,ed3;
   Button b1;

   public static final String MyPREFERENCES = "MyPrefs" ;
   public static final String Name = "nameKey";
   public static final String Phone = "phoneKey";
   public static final String Email = "emailKey";

   SharedPreferences sharedpreferences;

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

      ed1=(EditText)findViewById(R.id.editText);
      ed2=(EditText)findViewById(R.id.editText2);
      ed3=(EditText)findViewById(R.id.editText3);

      b1=(Button)findViewById(R.id.button);
      sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);

      b1.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            String n  = ed1.getText().toString();
            String ph  = ed2.getText().toString();
            String e  = ed3.getText().toString();

            SharedPreferences.Editor editor = sharedpreferences.edit();

            editor.putString(Name, n);
            editor.putString(Phone, ph);
            editor.putString(Email, e);
            editor.commit();
            Toast.makeText(MainActivity.this,"Thanks",Toast.LENGTH_LONG).show();
         }
      });
   }

}