提问人:Muhammad Maqsoodur Rehman 提问时间:9/2/2010 最后编辑:Igor TyulkanovMuhammad Maqsoodur Rehman 更新时间:6/27/2020 访问量:750296
如何在 Android 中使用 SharedPreferences 来存储、获取和编辑值 [已关闭]
How to use SharedPreferences in Android to store, fetch and edit values [closed]
问:
我想存储一个时间值,需要检索和编辑它。我该如何用它来做到这一点?SharedPreferences
答:
编辑数据sharedpreference
SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();
editor.putString("text", mSaved.getText().toString());
editor.putInt("selection-start", mSaved.getSelectionStart());
editor.putInt("selection-end", mSaved.getSelectionEnd());
editor.apply();
从中检索数据sharedpreference
SharedPreferences prefs = getPreferences(MODE_PRIVATE);
String restoredText = prefs.getString("text", null);
if (restoredText != null)
{
//mSaved.setText(restoredText, TextView.BufferType.EDITABLE);
int selectionStart = prefs.getInt("selection-start", -1);
int selectionEnd = prefs.getInt("selection-end", -1);
/*if (selectionStart != -1 && selectionEnd != -1)
{
mSaved.setSelection(selectionStart, selectionEnd);
}*/
}
编辑
我从 API 演示示例中获取了这个片段。它有一个盒子。在这种情况下,它不是必需的。我在评论同样的内容.EditText
context
评论
若要获取共享首选项,请使用以下方法 在您的活动中:
SharedPreferences prefs = this.getSharedPreferences(
"com.example.app", Context.MODE_PRIVATE);
要读取首选项:
String dateTimeKey = "com.example.app.datetime";
// use a default value using new Date()
long l = prefs.getLong(dateTimeKey, new Date().getTime());
编辑和保存首选项
Date dt = getSomeDate();
prefs.edit().putLong(dateTimeKey, dt.getTime()).apply();
android sdk 的示例目录包含检索和存储共享首选项的示例。它位于:
<android-sdk-home>/samples/android-<platformversion>/ApiDemos directory
编辑==>
我注意到,在这里写出 和 之间的区别也很重要。commit()
apply()
commit()
如果值保存成功,则返回,否则。它将值同步保存到 SharedPreferences。true
false
apply()
是在 2.3 中添加的,在成功或失败时不返回任何值。它会立即将值保存到 SharedPreferences,但会启动异步提交。
更多细节在这里。
评论
this.getSharedPreferences
给我以下错误:The method getSharedPreferences(String, int) is undefined for the type MyActivity
最简单的方法:
要保存:
getPreferences(MODE_PRIVATE).edit().putString("Name of variable",value).commit();
要检索:
your_variable = getPreferences(MODE_PRIVATE).getString("Name of variable",default value);
评论
要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();
要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*/
}
评论
Map<DateTime, Integer>
如何通过 存储登录值的简单解决方案。SharedPreferences
您可以扩展类或其他类,您将在其中存储“要保留的东西的值”。将其放入 writer 和 reader 类中:MainActivity
public static final String GAME_PREFERENCES_LOGIN = "Login";
这里分别是输入类和输出类。InputClass
OutputClass
// This is a storage, put this in a class which you can extend or in both classes:
//(input and output)
public static final String GAME_PREFERENCES_LOGIN = "Login";
// String from the text input (can be from anywhere)
String login = inputLogin.getText().toString();
// then to add a value in InputCalss "SAVE",
SharedPreferences example = getSharedPreferences(GAME_PREFERENCES_LOGIN, 0);
Editor editor = example.edit();
editor.putString("value", login);
editor.commit();
现在你可以在其他地方使用它,就像其他类一样。以下是 .OutputClass
SharedPreferences example = getSharedPreferences(GAME_PREFERENCES_LOGIN, 0);
String userString = example.getString("value", "defValue");
// the following will print it out in console
Logger.getLogger("Name of a OutputClass".class.getName()).log(Level.INFO, userString);
editor.putString("text", mSaved.getText().toString());
在这里,可以是任何,也可以是我们可以从哪里提取字符串。您可以简单地指定一个字符串。这里 text 将是保存从 ( 或 ) 获得的值的键。mSaved
TextView
EditText
mSaved
TextView
EditText
SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
此外,无需使用包名称(即“com.example.app”)保存首选项文件。您可以提及自己喜欢的名字。希望这有帮助!
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", "");
评论
在任何应用程序中,都有可以通过实例及其相关方法访问的默认首选项。PreferenceManager
getDefaultSharedPreferences(Context)
使用该实例,可以使用 getInt(String key, int defVal) 检索任何首选项的 int 值。在这种情况下,我们感兴趣的偏好是 反 .SharedPreference
在我们的例子中,我们可以使用 edit() 修改实例,并使用 我们增加了超出应用程序的应用程序的计数并相应地显示。SharedPreference
putInt(String key, int newVal)
为了进一步演示这一点,重新启动并再次使用应用程序,您会注意到每次重新启动应用程序时计数都会增加。
首选项演示.java
法典:
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
法典:
<?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>
存储信息
SharedPreferences preferences = getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("username", username.getText().toString());
editor.putString("password", password.getText().toString());
editor.putString("logged", "logged");
editor.commit();
重置首选项
SharedPreferences.Editor editor = preferences.edit();
editor.clear();
editor.commit();
使用这个简单的库,下面介绍如何调用 SharedPreferences。
TinyDB tinydb = new TinyDB(context);
tinydb.putInt("clickCount", 2);
tinydb.putString("userName", "john");
tinydb.putBoolean("isUserMale", true);
tinydb.putList("MyUsers", mUsersArray);
tinydb.putImagePNG("DropBox/WorkImages", "MeAtlunch.png", lunchBitmap);
//These plus the corresponding get methods are all Included
如果您正在与团队中的其他开发人员一起制作大型应用程序,并且打算在没有分散代码或不同的 SharedPreferences 实例的情况下将所有内容组织得井井有条,则可以执行以下操作:
//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 Activity 中,您可以通过以下方式保存 SharedPreferences
//saving a boolean into prefs
SharedPrefs.savePref(this, SharedPrefs.KEY_MY_SHARED_BOOLEAN, booleanVar);
您可以通过这种方式检索您的 SharedPreferences
//getting a boolean from prefs
booleanVar = SharedPrefs.getBoolean(this, SharedPrefs.KEY_MY_SHARED_BOOLEAN);
SharedPreferences 的基本思想是将内容存储在 XML 文件上。
声明 xml 文件路径。(如果您没有此文件,Android 将创建它。如果您有此文件,Android 将访问它。
SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
将值写入共享首选项
prefs.edit().putLong("preference_file_key", 1010101).apply();
是共享首选项文件的名称。这是您需要存储的值。
preference_file_key
1010101
apply()
最后是保存更改。如果收到错误,请将其更改为 。所以这个替代句是apply()
commit()
prefs.edit().putLong("preference_file_key", 1010101).commit();
从“共享偏好设置”中读取
SharedPreferences sp = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE); long lsp = sp.getLong("preference_file_key", -1);
lsp
如果没有值,则为如果“preference_file_key”有一个值,它将返回这个值。-1
preference_file_key
编写的整个代码是
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.
读取的代码是
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
评论
我想在这里补充一点,在使用 SharedPreferences 时,这个问题的大多数片段都会有类似 MODE_PRIVATE 的东西。好吧,MODE_PRIVATE意味着您写入此共享首选项的任何内容都只能由您的应用程序读取。
无论您将哪个键传递给 getSharedPreferences() 方法,android 都会创建一个具有该名称的文件,并将首选项数据存储到其中。 还要记住,当您打算为应用程序设置多个首选项文件时,应该使用 getSharedPreferences()。如果您打算使用单个首选项文件并将所有键值对存储到其中,请使用 getSharedPreference() 方法。奇怪的是,为什么每个人(包括我自己)都只是使用 getSharedPreferences() 风格,甚至不了解上述两者之间的区别。
以下视频教程应该对 https://www.youtube.com/watch?v=2PcAQ1NBy98 有所帮助
保存
PreferenceManager.getDefaultSharedPreferences(this).edit().putString("VarName","your value").apply();
检索 :
String name = PreferenceManager.getDefaultSharedPreferences(this).getString("VarName","defaultValue");
默认值为 :如果此首选项不存在,则要返回的值。
您可以使用 getActivity() 或 getApplicationContext() 更改 “this” 部分案例
评论
人们可以通过多种方式推荐如何使用 SharedPreferences。我在这里做了一个演示项目。示例中的关键点是使用 ApplicationContext 和单个 sharedpreferences 对象。这演示了如何将 SharedPreferences 与以下功能一起使用:-
- 使用 singelton 类访问/更新 SharedPreferences
- 无需始终为读/写 SharedPreferences 传递上下文
- 它使用 apply() 而不是 commit()
- apply() 是异步保存,不返回任何内容,它首先更新内存中的值,然后将更改写入磁盘 异步。
- commit() 是同步保存,它根据结果返回 true/false。更改将同步写入磁盘
- 适用于 Android 2.3+ 版本
使用示例如下:-
MyAppPreference.getInstance().setSampleStringKey("some_value");
String value= MyAppPreference.getInstance().getSampleStringKey();
在此处获取源代码,详细的 API 可以在 developer.android.com 上找到
评论
存储在 SharedPreferences 中
SharedPreferences preferences = getSharedPreferences("temp", getApplicationContext().MODE_PRIVATE);
Editor editor = preferences.edit();
editor.putString("name", name);
editor.commit();
在 SharedPreferences 中获取
SharedPreferences preferences=getSharedPreferences("temp", getApplicationContext().MODE_PRIVATE);
String name=preferences.getString("name",null);
注意:“temp”是共享首选项名称,“name”是输入值。如果 value 未退出,则返回 null
评论
您可以使用以下方法节省价值:
public void savePreferencesForReasonCode(Context context,
String key, String value) {
SharedPreferences sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(key, value);
editor.commit();
}
使用此方法,您可以从 SharedPreferences 中获取值:
public String getPreferences(Context context, String prefKey) {
SharedPreferences sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(context);
return sharedPreferences.getString(prefKey, "");
}
这是您用于保存特定值的密钥。谢谢。prefKey
评论
有史以来的最佳实践
创建以 PreferenceManager 命名的接口:
// 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);
}
如何与 Activity / Fragment 一起使用:
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:将 SharedPreference 的密钥替换为 SP_TITLE。
例子:
在 shareperence 中存储字符串:
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。
评论
简单无忧 :: “Android-SharedPreferences-Helper” 库
迟到总比没有好:我创建了“Android-SharedPreferences-Helper”库,以帮助降低使用 .它还提供了一些扩展功能。它提供的几件事如下:SharedPreferences
- 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
- 每个数据类型的预定义(数据类型默认值)和可自定义(您可以选择)默认值
- 只需一个额外的参数即可为单次使用设置不同的默认值
- 您可以注册和注销 OnSharedPreferenceChangeListener,就像注册和注销默认类一样
dependencies {
...
...
compile(group: 'com.viralypatel.sharedpreferenceshelper', name: 'library', version: '1.1.0', ext: 'aar')
}
SharedPreferencesHelper 对象的声明:(在类中推荐) 水平)
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
将值放入共享首选项中
相当简单!与默认方式(使用 SharedPreferences 类时)不同,您不需要调用任何时间。.edit()
.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,只需使用键名称进行一次简单的方法调用。
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");
它还有许多其他扩展功能
在 GitHub 存储库页面上查看扩展功能、用法和安装说明等的详细信息。
评论
在这里,我创建了一个 Helper 类来使用 android 中的首选项。
这是帮助程序类:
public class PrefsUtil {
public static SharedPreferences getPreference() {
return PreferenceManager.getDefaultSharedPreferences(Applicatoin.getAppContext());
}
public static void putBoolean(String key, boolean value) {
getPreference().edit().putBoolean(key, value)
.apply();
}
public static boolean getBoolean(String key) {
return getPreference().getBoolean(key, false);
}
public static void putInt(String key, int value) {
getPreference().edit().putInt(key, value).apply();
}
public static void delKey(String key) {
getPreference().edit().remove(key).apply();
}
}
以函数方式存储和检索全局变量。
若要进行测试,请确保页面上有 Textview 项,取消对代码中的两行的注释,然后运行。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。
在要使用它的每个类中,在末尾添加这两个例程。 我希望这个例程是全局例程,但不知道如何。这行得通。
variabels 随处可见。 它将变量存储在“MyFile”中。你可以用自己的方式改变它。
你用
storeSession("username","frans");
storeSession("password","!2#4%");***
变量 username 将填充“frans”,密码将填充为“!2#4%”。即使在重新启动后,它们也可用。
然后你使用
password.setText(getSession(("password")));
usernames.setText(getSession(("username")));
在我的网格.java的整个代码下面
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","[email protected]");
//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;
}
}
在下面找到 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" />
Singleton Shared Preferences 类。 它可能会在未来对其他人有所帮助。
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
public class SharedPref
{
private static SharedPreferences mSharedPref;
public static final String NAME = "NAME";
public static final String AGE = "AGE";
public static final String IS_SELECT = "IS_SELECT";
private SharedPref()
{
}
public static void init(Context context)
{
if(mSharedPref == null)
mSharedPref = context.getSharedPreferences(context.getPackageName(), Activity.MODE_PRIVATE);
}
public static String read(String key, String defValue) {
return mSharedPref.getString(key, defValue);
}
public static void write(String key, String value) {
SharedPreferences.Editor prefsEditor = mSharedPref.edit();
prefsEditor.putString(key, value);
prefsEditor.commit();
}
public static boolean read(String key, boolean defValue) {
return mSharedPref.getBoolean(key, defValue);
}
public static void write(String key, boolean value) {
SharedPreferences.Editor prefsEditor = mSharedPref.edit();
prefsEditor.putBoolean(key, value);
prefsEditor.commit();
}
public static Integer read(String key, int defValue) {
return mSharedPref.getInt(key, defValue);
}
public static void write(String key, Integer value) {
SharedPreferences.Editor prefsEditor = mSharedPref.edit();
prefsEditor.putInt(key, value).commit();
}
}
只需拨打一次电话SharedPref.init()
MainActivity
SharedPref.init(getApplicationContext());
写入数据
SharedPref.write(SharedPref.NAME, "XXXX");//save string in shared preference.
SharedPref.write(SharedPref.AGE, 25);//save int in shared preference.
SharedPref.write(SharedPref.IS_SELECT, true);//save boolean in shared preference.
读取数据
String name = SharedPref.read(SharedPref.NAME, null);//read string in shared preference.
int age = SharedPref.read(SharedPref.AGE, 0);//read int in shared preference.
boolean isSelect = SharedPref.read(SharedPref.IS_SELECT, false);//read boolean in shared preference.
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我为 sharedpreferences 编写了一个辅助类:
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;
}
}
我创建了一个 Helper 类来让我的生活变得轻松。这是一个通用类,具有许多常用的方法,例如共享首选项、电子邮件有效性、日期时间格式等应用程序。在代码中复制此类,并在需要时随时访问其方法。
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;
}
}
编辑
SharedPreferences pref = getSharedPreferences("YourPref", MODE_PRIVATE);
SharedPreferences.Editor editor = pref.edit();
editor.putString("yourValue", value);
editor.commit();
读
SharedPreferences pref = getSharedPreferences("YourPref", MODE_PRIVATE);
value= pref.getString("yourValue", "");
要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();
要从共享首选项中检索值:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
String name = sp.getString("Name", "");
使用这个例子简单明了,并检查了
<?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();
}
});
}
}
SharedPreferences.Editor editor = getSharedPreferences("identifier",
MODE_PRIVATE).edit();
//identifier is the unique to fetch data from your SharedPreference.
editor.putInt("keyword", 0);
// saved value place with 0.
//use this "keyword" to fetch saved value again.
editor.commit();//important line without this line your value is not stored in preference
// fetch the stored data using ....
SharedPreferences prefs = getSharedPreferences("identifier", MODE_PRIVATE);
// here both identifier will same
int fetchvalue = prefs.getInt("keyword", 0);
// here keyword will same as used above.
// 0 is default value when you nothing save in preference that time fetch value is 0.
您需要在 AdapterClass 或任何其他 AdapterClass 中使用 SharedPreferences。 那个时候只需使用此声明并使用上面相同的屁股。
SharedPreferences.Editor editor = context.getSharedPreferences("idetifier",
Context.MODE_PRIVATE).edit();
SharedPreferences prefs = context.getSharedPreferences("identifier", Context.MODE_PRIVATE);
//here context is your application context
对于字符串或布尔值
editor.putString("stringkeyword", "your string");
editor.putBoolean("booleankeyword","your boolean value");
editor.commit();
获取数据与上述相同
String fetchvalue = prefs.getString("keyword", "");
Boolean fetchvalue = prefs.getBoolean("keyword", "");
要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();
要从共享首选项中检索值:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
String name = sp.getString("Name", ""); // Second parameter is the default value.
2.用于共享存储
SharedPreferences.Editor editor =
getSharedPreferences("DeviceToken",MODE_PRIVATE).edit();
editor.putString("DeviceTokenkey","ABABABABABABABB12345");
editor.apply();
2.用于检索相同的用途
SharedPreferences prefs = getSharedPreferences("DeviceToken",
MODE_PRIVATE);
String deviceToken = prefs.getString("DeviceTokenkey", null);
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