我想存储一个时间值,需要检索和编辑它。我如何使用SharedPreferences来做到这一点?


当前回答

您可以使用以下方法保存值:

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();
    }

使用这个方法,你可以从SharedPreferences中获取值:

public String getPreferences(Context context, String prefKey) {
  SharedPreferences sharedPreferences = PreferenceManager
 .getDefaultSharedPreferences(context);
 return sharedPreferences.getString(prefKey, "");
}

这里prefKey是用来保存特定值的键。谢谢。

其他回答

您可以使用以下方法保存值:

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();
    }

使用这个方法,你可以从SharedPreferences中获取值:

public String getPreferences(Context context, String prefKey) {
  SharedPreferences sharedPreferences = PreferenceManager
 .getDefaultSharedPreferences(context);
 return sharedPreferences.getString(prefKey, "");
}

这里prefKey是用来保存特定值的键。谢谢。

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。

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.

你需要在AdapterClass或任何其他类中使用SharedPreferences。 那一次只是使用这个声明和使用相同的屁股上面。

SharedPreferences.Editor editor = context.getSharedPreferences("idetifier", 
Context.MODE_PRIVATE).edit();
SharedPreferences prefs = context.getSharedPreferences("identifier", Context.MODE_PRIVATE);

//here context is your application context

用于字符串或布尔值

editor.putString("stringkeyword", "your string"); 
editor.putBoolean("booleankeyword","your boolean value");
editor.commit();

取数据与上面相同

String fetchvalue = prefs.getString("keyword", "");
Boolean fetchvalue = prefs.getBoolean("keyword", "");

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();
         }
      });
   }

}

在这里,我创建了一个Helper类来使用android中的首选项。

这是helper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();

}

}