SharedPreferences for Android Storage

SharedPreferences is a lightweight storage class on the Android platform. It mainly stores some common configurations, such as window status. Generally, reload the window status onSaveInstanceState in the Activity and save it using SharedPreferences, it stores Long integer, Int integer, and String types on the Android platform. The information is saved in the/data/PACKAGE_NAME/shared_prefs directory as an XML file.

SharedPreferencespre = getSharedPreferences ("soft", Context. MODE_WORLD_READABLE );

Here we can call the method provided by activity. This method has two parameters:

1). file name. Pay special attention here. In Android, it has been confirmed that SharedPreferences are saved in the xm l format. Therefore, when entering the file name parameter, do not specify the suffix ". xml". android will automatically add it. It stores parameters in the form of key-value pairs. When you need to obtain a parameter value, you can index it according to the key of the parameter.

2). The second one can be understood as the creation mode is the same as the previous file storage mode.

Context. MODE_PRIVATE

Context. MODE_APPEND

Context. MODE_WORLD_READABLE

Context. MODE_WORLD_WRITEABLE

 

Lab procedure

Interface:

 

1. Resources

<String name = "name_text"> name </string>
<String name = "age_text"> age </string>
<String name = "save_text"> submit </string>
<String name = "name_text"> name </string>
<String name = "age_text"> age </string>
<String name = "save_text"> submit </string>

 

2. Layout

<? Xml version = "1.0" encoding = "UTF-8"?>
<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
Android: layout_width = "fill_parent"
Android: layout_height = "fill_parent"
Android: orientation = "vertical">
 
<LinearLayout
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: orientation = "horizontal">
 
<TextView
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginRight = "30dp"
Android: text = "@ string/name_text"/>
 
<EditText
Android: id = "@ + id/nameEt"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"/>
</LinearLayout>
 
<LinearLayout
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: orientation = "horizontal">
 
<TextView
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginRight = "30dp"
Android: text = "@ string/age_text"/>
 
<EditText
Android: id = "@ + id/ageEt"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"/>
</LinearLayout>
 
<Button
Android: id = "@ + id/saveBtn"
Android: layout_marginTop = "30dp"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: text = "@ string/save_text"/>
</LinearLayout>
<? Xml version = "1.0" encoding = "UTF-8"?>
<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
Android: layout_width = "fill_parent"
Android: layout_height = "fill_parent"
Android: orientation = "vertical">

<LinearLayout
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: orientation = "horizontal">

<TextView
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginRight = "30dp"
Android: text = "@ string/name_text"/>

<EditText
Android: id = "@ + id/nameEt"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"/>
</LinearLayout>

<LinearLayout
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: orientation = "horizontal">

<TextView
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginRight = "30dp"
Android: text = "@ string/age_text"/>

<EditText
Android: id = "@ + id/ageEt"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"/>
</LinearLayout>

<Button
Android: id = "@ + id/saveBtn"
Android: layout_marginTop = "30dp"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: text = "@ string/save_text"/>
</LinearLayout>

3. Save

Private void findViews (){
NameEt = (EditText) this. findViewById (R. id. nameEt );
AgeEt = (EditText) this. findViewById (R. id. ageEt );
SaveBtn = (Button) this. findViewById (R. id. saveBtn );
 
SaveBtn. setOnClickListener (new View. OnClickListener (){
 
Public void onClick (View v ){

String name = nameEt. getText (). toString (). trim ();
Int age =
Integer. valueOf (ageEt. getText (). toString (). trim ());

SharedPreferences sharedPreferences =
SharedpreferencesTestActivity. this
. GetSharedPreferences ("myOption", MODE_PRIVATE );
Editor editor = sharedPreferences. edit ();
Editor. putString ("name", name );
Editor. putInt ("age", age );

Editor. commit ();
}
});
}
Private void findViews (){
NameEt = (EditText) this. findViewById (R. id. nameEt );
AgeEt = (EditText) this. findViewById (R. id. ageEt );
SaveBtn = (Button) this. findViewById (R. id. saveBtn );

SaveBtn. setOnClickListener (new View. OnClickListener (){

Public void onClick (View v ){
 
String name = nameEt. getText (). toString (). trim ();
Int age =
Integer. valueOf (ageEt. getText (). toString (). trim ());

SharedPreferences sharedPreferences =
SharedpreferencesTestActivity. this
. GetSharedPreferences ("myOption", MODE_PRIVATE );
Editor editor = sharedPreferences. edit ();
Editor. putString ("name", name );
Editor. putInt ("age", age );

Editor. commit ();
}
});
}

4. added the READ function.

 

Add Resource

<String name = "read_text"> Read </string>
<String name = "read_text"> Read </string>

Change layout

<TableLayout
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: layout_margin = "15dp"
Android: stretchColumns = "*">
 
<TableRow>
<Button
Android: id = "@ + id/saveBtn"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginTop = "30dp"
Android: text = "@ string/save_text"/>
 
<Button
Android: id = "@ + id/readBtn"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginTop = "30dp"
Android: text = "@ string/read_text"/>
</TableRow>
</TableLayout>
<TableLayout
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: layout_margin = "15dp"
Android: stretchColumns = "*">

<TableRow>
<Button
Android: id = "@ + id/saveBtn"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginTop = "30dp"
Android: text = "@ string/save_text"/>

<Button
Android: id = "@ + id/readBtn"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginTop = "30dp"
Android: text = "@ string/read_text"/>
</TableRow>
</TableLayout>
 
Code

Public void onClick (View v ){
SharedPreferences sp = getSharedPreferences ("myOption ",
MODE_PRIVATE );
String name = "anonymous ";
Int age =-1;

Switch (v. getId ()){
Case R. id. saveBtn:
Name = nameEt. getText (). toString (). trim ();
Age = Integer. valueOf (ageEt. getText (). toString (). trim ());
 
Editor editor = sp. edit ();
Editor. putString ("name", name );
Editor. putInt ("age", age );
 
Editor. commit ();
Break;
Case R. id. readBtn:
Name = sp. getString ("name", "anonymous ");
Age = sp. getInt ("age",-1 );
Toast. makeText (this,
"Name:" + name + "age:" + String. valueOf (age ),
Toast. LENGTH_SHORT). show ();
Break;
}
}
Public void onClick (View v ){
SharedPreferences sp = getSharedPreferences ("myOption ",
MODE_PRIVATE );
String name = "anonymous ";
Int age =-1;
 
Switch (v. getId ()){
Case R. id. saveBtn:
Name = nameEt. getText (). toString (). trim ();
Age = Integer. valueOf (ageEt. getText (). toString (). trim ());

Editor editor = sp. edit ();
Editor. putString ("name", name );
Editor. putInt ("age", age );

Editor. commit ();
Break;
Case R. id. readBtn:
Name = sp. getString ("name", "anonymous ");
Age = sp. getInt ("age",-1 );
Toast. makeText (this,
"Name:" + name + "age:" + String. valueOf (age ),
Toast. LENGTH_SHORT). show ();
Break;
}
}

Author: jjaze3344