SharedPreferences的用法
1.创建Android工程
Project name:sharedPreferences
BuildTarget:Android2.2
Application name:软件参数设置
Package name:com.com.jbridge.pres.activity
Create Activity:PreferencesActivity
Min SDK Version:8
2.编辑strings.xml：
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, PreferencesActivity!</string>
<string name="app_name">软件参数设置</string>
<string name="tv_name">姓名</string>
<string name="tv_age">年龄</string>
<string name="bt_write">设置</string>
<string name="bt_read">读取</string>
<string name="save_success">保存成功</string>
<string name="save_failed">保存失败</string>
</resources>
3.编辑main.xml
<?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"
>
<RelativeLayout android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/tv_name"
android:id="@+id/tv_name"
android:textSize="30px"
/>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/et_name"
android:layout_toRightOf="@id/tv_name"
android:layout_alignTop="@id/tv_name"
android:layout_marginLeft="30px"
/>
</RelativeLayout>
<RelativeLayout android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/tv_age"
android:id="@+id/tv_age"
android:textSize="30px"
/>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/et_age"
android:layout_toRightOf="@id/tv_age"
android:layout_alignTop="@id/tv_age"
android:layout_marginLeft="30px"
/>
</RelativeLayout>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bt_write"
android:text="@string/bt_write"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bt_read"
android:text="@string/bt_read"
android:layout_toRightOf="@id/bt_write"
android:layout_alignTop="@id/bt_write"
android:layout_marginLeft="30px"
/>
</RelativeLayout>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/tv_show"
/>
</LinearLayout>
4.为按钮添加事件代码
package com.jbridge.pres.activity;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.content.res.Resources.NotFoundException;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class PreferencesActivity extends Activity {
private EditText etName;
private EditText etAge;
private View.OnClickListener onClickListener=new View.OnClickListener() {
public void onClick(View view) {
Button button=(Button) view;
SharedPreferences sharedPreferences=PreferencesActivity.this.getSharedPreferences("zyj", Context.MODE_PRIVATE);
switch (button.getId()) {
case R.id.bt_write:
try {
Editor editor=sharedPreferences.edit();
editor.putString("name", etName.getText().toString());
editor.putInt("age",Integer.valueOf(etAge.getText().toString()) );
editor.commit();
Toast.makeText(PreferencesActivity.this, R.string.save_success, Toast.LENGTH_LONG).show();
} catch (NumberFormatException e) {
Toast.makeText(PreferencesActivity.this, R.string.save_failed, Toast.LENGTH_LONG).show();;
e.printStackTrace();
} catch (NotFoundException e) {
Toast.makeText(PreferencesActivity.this, R.string.save_failed, Toast.LENGTH_LONG).show();;
e.printStackTrace();
}
break;
case R.id.bt_read:
String name=sharedPreferences.getString("name", "no name");
String age=String.valueOf(sharedPreferences.getInt("age", 0));
TextView tvShow=(TextView) PreferencesActivity.this.findViewById(R.id.tv_show);
tvShow.setText("姓名： "+name+" 年龄: "+age);
break;
default:
break;
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SharedPreferences sharedPreferences=PreferencesActivity.this.getSharedPreferences("zyj", Context.MODE_PRIVATE);
etName=(EditText) this.findViewById(R.id.et_name);
etAge=(EditText) this.findViewById(R.id.et_age);
etName.setText(sharedPreferences.getString("name", "no name"));
etAge.setText(String.valueOf(sharedPreferences.getInt("age", 0)));
Button btWrite=(Button) this.findViewById(R.id.bt_write);
Button btRead=(Button) this.findViewById(R.id.bt_read);
btWrite.setOnClickListener(onClickListener);
btRead.setOnClickListener(onClickListener);
}
/*
如果访问其他应用中的Preference，前提条件是：该preference创建时指定了Context.MODE_WORLD_READABLE或者Context.MODE_WORLD_WRITEABLE权限。如：有个<package name>为com.jbridge.pres.activity的应用使用下面语句创建了preference。
getSharedPreferences("zyj", Context.MODE_WORLD_READABLE);
其他应用要访问上面应用的preference，首先需要创建上面应用的Context，然后通过Context 访问preference ，访问preference时会在应用所在包下的shared_prefs目录找到preference ：
Context otherAppsContext = createPackageContext("com.jbridge.pres.activity", Context.CONTEXT_IGNORE_SECURITY);
SharedPreferences sharedPreferences = otherAppsContext.getSharedPreferences("zyj", Context.MODE_WORLD_READABLE);
String name = sharedPreferences.getString("name", "no name");
int age = sharedPreferences.getInt("age", 0);
*/
}
5.运行程序启动模拟器，运行程序。输入名称和年龄，点击保存。我们使用的代码是getSharedPreferences("zyj",Context.MODE_PRIVATE);，当然commit时。它会为我们为”/data/data/com.jbridge.pres.activity/shared_prefszyj.xml”。将 preferences.xml导出，查看它的内容为：
<?xml version=‘1.0‘ encoding=‘utf-8‘ standalone=‘yes‘ ?><map><string name="name">zyj</string><int name="age" value="22" /></map>