Android共享首选项示例

Question

我想在应用程序中检索用户输入以供以后使用.

例如,系统会提示用户输入一周中的所有7天,并在editText框中键入"星期一","星期二"等.然后在应用程序中稍后会出现一个问题,询问您最喜欢的一天是什么时候？微调器将显示他们输入的日期的下拉列表供用户选择.

我想共享偏好对此有用,但我找不到一个很好的例子来给我一个起点.任何帮助,将不胜感激.

Answer 1

在偏好中设置值:

// MY_PREFS_NAME - a static String variable like: 
//public static final String MY_PREFS_NAME = "MyPrefsFile";
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
 editor.putString("name", "Elena");
 editor.putInt("idName", 12);
 editor.apply();

从首选项中检索数据:

SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE); 
String name = prefs.getString("name", "No name defined");//"No name defined" is the default value.
int idName = prefs.getInt("idName", 0); //0 is the default value.

更多信息:

使用共享首选项

共享首选项

Answer 2

创建SharedPreferences

SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", MODE_PRIVATE); 
Editor editor = pref.edit();

将数据存储为KEY/VALUE对

editor.putBoolean("key_name1", true);           // Saving boolean - true/false
editor.putInt("key_name2", "int value");        // Saving integer
editor.putFloat("key_name3", "float value");    // Saving float
editor.putLong("key_name4", "long value");      // Saving long
editor.putString("key_name5", "string value");  // Saving string

// Save the changes in SharedPreferences
editor.apply(); // commit changes

获取SharedPreferences数据

//如果key的值不存在则返回第二个参数值 - 在这种情况下为null

boolean userFirstLogin= pref.getBoolean("key_name1", true);  // getting boolean
int pageNumber=pref.getInt("key_name2", 0);             // getting Integer
float amount=pref.getFloat("key_name3", null);          // getting Float
long distance=pref.getLong("key_name4", null);          // getting Long
String email=pref.getString("key_name5", null);         // getting String

从SharedPreferences中删除键值

editor.remove("key_name3"); // will delete key key_name3
editor.remove("key_name4"); // will delete key key_name4

// Save the changes in SharedPreferences
editor.apply(); // commit changes

清除SharedPreferences中的所有数据

 editor.clear();
 editor.apply(); // commit changes

Answer 3

如何初学？

// 0 - for private mode`
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", 0); 

Editor editor = pref.edit();

如何在共享首选项中存储数据？

editor.putString("key_name", "string value"); // Storing string

要么

editor.putInt("key_name", "int value"); //Storing integer

并且不要忘记申请:

editor.apply();

如何从共享首选项中检索数据？

pref.getString("key_name", null); // getting String

pref.getInt("key_name", 0); // getting Integer

希望这会帮助你:)

Answer 4

您可以创建自定义SharedPreference类

public class YourPreference {   
    private static YourPreference yourPreference;
    private SharedPreferences sharedPreferences;

    public static YourPreference getInstance(Context context) {
        if (yourPreference == null) {
            yourPreference = new YourPreference(context);
        }
        return yourPreference;
    }

    private YourPreference(Context context) {
        sharedPreferences = context.getSharedPreferences("YourCustomNamedPreference",Context.MODE_PRIVATE);
    }

    public void saveData(String key,String value) {
        SharedPreferences.Editor prefsEditor = sharedPreferences.edit();
        prefsEditor .putString(key, value);
        prefsEditor.commit();           
    }

    public String getData(String key) {
        if (sharedPreferences!= null) {
           return sharedPreferences.getString(key, "");
        }
        return "";         
    }
}

你可以得到YourPrefrence实例,如:

YourPreference yourPrefrence = YourPreference.getInstance(context);
yourPreference.saveData(YOUR_KEY,YOUR_VALUE);

String value = yourPreference.getData(YOUR_KEY);

Answer 5

我刚刚发现以上所有例子都太混乱了,所以我写了自己的.如果你知道你在做什么,代码碎片就没问题了,但是像我这样的人却没有？

想要一个切割粘贴解决方案吗？好吧,这是!

创建一个新的java文件并将其命名为Keystore.然后粘贴此代码:

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Log;

public class Keystore { //Did you remember to vote up my example?
    private static Keystore store;
    private SharedPreferences SP;
    private static String filename="Keys";

private Keystore(Context context) {
    SP = context.getApplicationContext().getSharedPreferences(filename,0);
}

public static Keystore getInstance(Context context) {
    if (store == null) {
        Log.v("Keystore","NEW STORE");
        store = new Keystore(context);
    }
    return store;
}

public void put(String key, String value) {//Log.v("Keystore","PUT "+key+" "+value);
    Editor editor = SP.edit();
    editor.putString(key, value);
    editor.commit(); // Stop everything and do an immediate save!
    // editor.apply();//Keep going and save when you are not busy - Available only in APIs 9 and above.  This is the preferred way of saving.
}

public String get(String key) {//Log.v("Keystore","GET from "+key);
    return SP.getString(key, null);

}

public int getInt(String key) {//Log.v("Keystore","GET INT from "+key);
    return SP.getInt(key, 0);
}

public void putInt(String key, int num) {//Log.v("Keystore","PUT INT "+key+" "+String.valueOf(num));
    Editor editor = SP.edit();

    editor.putInt(key, num);
    editor.commit();
}


public void clear(){ // Delete all shared preferences
    Editor editor = SP.edit();

    editor.clear();
    editor.commit();
}

public void remove(){ // Delete only the shared preference that you want
    Editor editor = SP.edit();

    editor.remove(filename);
    editor.commit();
}
}

现在保存该文件并忘记它.你完成了它.现在回到你的活动中并像这样使用它:

public class YourClass extends Activity{

private Keystore store;//Holds our key pairs

public YourSub(Context context){
    store = Keystore.getInstance(context);//Creates or Gets our key pairs.  You MUST have access to current context!

    int= store.getInt("key name to get int value");
    string = store.get("key name to get string value");

    store.putInt("key name to store int value",int_var);
    store.put("key name to store string value",string_var);
    }
}

Answer 6

Shared Preferences是用于将私有原始数据存储在键值对中的XML文件.数据类型包括布尔值,浮点数,整数,长整数和字符串.

当我们想要保存一些可在整个应用程序中访问的数据时,一种方法是将其保存在全局变量中.但是一旦申请被关闭,它就会消失.另一种推荐的方法是保存SharedPreference.保存在SharedPreferences文件中的数据可在整个应用程序中访问,并且即使在应用程序关闭或重新启动后仍会保留.

SharedPreferences将数据保存在键值对中,并且可以以相同的方式访问.

您可以SharedPreferences使用两种方法创建Object ,

1).getSharedPreferences():使用此方法,您可以创建多个SharedPreferences.and它的第一个参数名称SharedPreferences.

2).getPreferences():使用此方法可以创建Single SharedPreferences.

存储数据

添加变量声明/创建首选项文件

public static final String PREFERENCES_FILE_NAME = "MyAppPreferences";

检索文件名的句柄(使用getSharedPreferences)

SharedPreferences settingsfile= getSharedPreferences(PREFERENCES_FILE_NAME,0);

打开编辑器和添加键值对

SharedPreferences.Editor myeditor = settingsfile.edit(); 
myeditor.putBoolean("IITAMIYO", true); 
myeditor.putFloat("VOLUME", 0.7)
myeditor.putInt("BORDER", 2)
myeditor.putLong("SIZE", 12345678910L)
myeditor.putString("Name", "Amiyo")
myeditor.apply(); 

不要忘记使用myeditor.apply()如上所示的使用/保存.

检索数据

 SharedPreferences mysettings= getSharedPreferences(PREFERENCES_FILE_NAME, 0);
IITAMIYO = mysettings.getBoolean("IITAMIYO", false); 
//returns value for the given key. 
//second parameter gives the default value if no user preference found
// (set to false in above case)
VOLUME = mysettings.getFloat("VOLUME", 0.5) 
//0.5 being the default value if no volume preferences found
// and similarly there are get methods for other data types

Answer 7

public class Preferences {

public static final String PREF_NAME = "your preferences name";

@SuppressWarnings("deprecation")
public static final int MODE = Context.MODE_WORLD_WRITEABLE;

public static final String USER_ID = "USER_ID_NEW";
public static final String USER_NAME = "USER_NAME";

public static final String NAME = "NAME";
public static final String EMAIL = "EMAIL";
public static final String PHONE = "PHONE";
public static final String address = "address";

public static void writeBoolean(Context context, String key, boolean value) {
    getEditor(context).putBoolean(key, value).commit();
}

public static boolean readBoolean(Context context, String key,
        boolean defValue) {
    return getPreferences(context).getBoolean(key, defValue);
}

public static void writeInteger(Context context, String key, int value) {
    getEditor(context).putInt(key, value).commit();

}

public static int readInteger(Context context, String key, int defValue) {
    return getPreferences(context).getInt(key, defValue);
}

public static void writeString(Context context, String key, String value) {
    getEditor(context).putString(key, value).commit();

}

public static String readString(Context context, String key, String defValue) {
    return getPreferences(context).getString(key, defValue);
}

public static void writeFloat(Context context, String key, float value) {
    getEditor(context).putFloat(key, value).commit();
}

public static float readFloat(Context context, String key, float defValue) {
    return getPreferences(context).getFloat(key, defValue);
}

public static void writeLong(Context context, String key, long value) {
    getEditor(context).putLong(key, value).commit();
}

public static long readLong(Context context, String key, long defValue) {
    return getPreferences(context).getLong(key, defValue);
}

public static SharedPreferences getPreferences(Context context) {
    return context.getSharedPreferences(PREF_NAME, MODE);
}

public static Editor getEditor(Context context) {
    return getPreferences(context).edit();
}

}

****使用首选项写入值使用: - ****

Preferences.writeString(getApplicationContext(),
                    Preferences.NAME, "dev");

****使用首选项读取值: - ****

Preferences.readString(getApplicationContext(), Preferences.NAME,
                    "");

Answer 8

创建SharedPreference和供全球使用的最佳方法是，您需要创建一个如下所示的类：

public class PreferenceHelperDemo {
    private final SharedPreferences mPrefs;

    public PreferenceHelperDemo(Context context) {
        mPrefs = PreferenceManager.getDefaultSharedPreferences(context);
    }

    private String PREF_Key= "Key";

    public String getKey() {
        String str = mPrefs.getString(PREF_Key, "");
        return str;
    }

    public void setKey(String pREF_Key) {
        Editor mEditor = mPrefs.edit();
        mEditor.putString(PREF_Key, pREF_Key);
        mEditor.apply();
    }

}

Answer 9

SharedPreferences mPref;
SharedPreferences.Editor editor;

public SharedPrefrences(Context mContext) {
    mPref = mContext.getSharedPreferences(Constant.SharedPreferences, Context.MODE_PRIVATE);
    editor=mPref.edit();
}

public void setLocation(String latitude, String longitude) {
    SharedPreferences.Editor editor = mPref.edit();
    editor.putString("latitude", latitude);
    editor.putString("longitude", longitude);
    editor.apply();
}

public String getLatitude() {
    return mPref.getString("latitude", "");
}

public String getLongitude() {
    return mPref.getString("longitude", "");
}

public void setGCM(String gcm_id, String device_id) {
     editor.putString("gcm_id", gcm_id);
    editor.putString("device_id", device_id);
    editor.apply();
}

public String getGCMId() {
    return mPref.getString("gcm_id", "");
}

public String getDeviceId() {
    return mPref.getString("device_id", "");
}


public void setUserData(User user){

    Gson gson = new Gson();
    String json = gson.toJson(user);
    editor.putString("user", json);
    editor.apply();
}
public User getUserData(){
    Gson gson = new Gson();
    String json = mPref.getString("user", "");
    User user = gson.fromJson(json, User.class);
    return user;
}

public void setSocialMediaStatus(SocialMedialStatus status){

    Gson gson = new Gson();
    String json = gson.toJson(status);
    editor.putString("status", json);
    editor.apply();
}
public SocialMedialStatus getSocialMediaStatus(){
    Gson gson = new Gson();
    String json = mPref.getString("status", "");
    SocialMedialStatus status = gson.fromJson(json, SocialMedialStatus.class);
    return status;
}