Android开发之SharedPreferences的封装

对于大部分初学者来说，如果想利用SharedPreferences进行数据存储的话大部分人(包括本人)应该会这样：

存储：

    SharedPreferences sharedPreferences = getSharedPreferences(context.getPackageName(), Context.MODE_PRIVATE);  Editor editor = sharedPreferences.edit();  editor.putString("username", "Tom");  editor.putInt("password", 123456);  editor.commit();  

获取：

    SharedPreferences sharedPreferences = getSharedPreferences(context.getPackageName(), Context.MODE_PRIVATE);  String username = sharedPreferences.getString("username", "");  int password = sharedPreferences.getInt("password", 0);  

虽然这样做代码没多少，如果是对于初学者练习来说无伤大雅。但是如果你是做一个项目开发来说，里面使用了大量的数据存数。每次都将上面的代码一遍一遍的重复，估计能让人崩溃。所以，对于实际项目开发来说，最好能将可以封装的工具类封装就进行封装。

下面是一个封装好的SharedPreferences的工具类，如果你有需要直接引用就OK：

package com.example.utl;import java.util.Map;import android.content.Context;
import android.content.SharedPreferences;/*** 保存信息配置类* * @author admin*/
public class SharedPreferencesHelper {private SharedPreferences sharedPreferences;/** 保存手机里面的名字*/private SharedPreferences.Editor editor;public SharedPreferencesHelper(Context context,String FILE_NAME) {sharedPreferences = context.getSharedPreferences(FILE_NAME,Context.MODE_PRIVATE);editor = sharedPreferences.edit();}/*** 存储*/public void put(String key, Object object) {if (object instanceof String) {editor.putString(key, (String) object);} else if (object instanceof Integer) {editor.putInt(key, (Integer) object);} else if (object instanceof Boolean) {editor.putBoolean(key, (Boolean) object);} else if (object instanceof Float) {editor.putFloat(key, (Float) object);} else if (object instanceof Long) {editor.putLong(key, (Long) object);} else {editor.putString(key, object.toString());}editor.commit();}/*** 获取保存的数据*/public Object getSharedPreference(String key, Object defaultObject) {if (defaultObject instanceof String) {return sharedPreferences.getString(key, (String) defaultObject);} else if (defaultObject instanceof Integer) {return sharedPreferences.getInt(key, (Integer) defaultObject);} else if (defaultObject instanceof Boolean) {return sharedPreferences.getBoolean(key, (Boolean) defaultObject);} else if (defaultObject instanceof Float) {return sharedPreferences.getFloat(key, (Float) defaultObject);} else if (defaultObject instanceof Long) {return sharedPreferences.getLong(key, (Long) defaultObject);} else {return sharedPreferences.getString(key, null);}}/*** 移除某个key值已经对应的值*/public void remove(String key) {editor.remove(key);editor.commit();}/*** 清除所有数据*/public void clear() {editor.clear();editor.commit();}/*** 查询某个key是否存在*/public Boolean contain(String key) {return sharedPreferences.contains(key);}/*** 返回所有的键值对*/public Map<String, ?> getAll() {return sharedPreferences.getAll();}
}

登录界面：

 Activity中应用：

/*** 登录界面* * @author admin* */
public class LoginActivity extends Activity implements OnClickListener {private EditText username;private EditText password;private Button login;// 登录按钮private CheckBox holdPwd;// 保存用户和密码private MyDialog mydialog;// 自定义对话框private SharedPreferencesHelper sharedPreferencesHelper;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.activity_login);init();}/*** 初始化界面*/private void init() {sharedPreferencesHelper = new SharedPreferencesHelper(LoginActivity.this, "anhua");username = (EditText) findViewById(R.id.username);password = (EditText) findViewById(R.id.password);holdPwd = (CheckBox) findViewById(R.id.login_hold);holdPwd.setChecked(true);
　　　　 //取出存储的值在登陆界面中显示username.setText(sharedPreferencesHelper.getSharedPreference("username", "").toString().trim());password.setText(sharedPreferencesHelper.getSharedPreference("password", "").toString().trim());
login = (Button) findViewById(R.id.login);login.setOnClickListener(this);}
@Overridepublic void onClick(View v) {// TODO Auto-generated method stubswitch (v.getId()) {case R.id.login:login();break;default:break;}}private void login() {String name = username.getText().toString().trim();String pwd = password.getText().toString().trim();
　　　　　//如果复选框被选中则存储账户和密码if (holdPwd.isChecked()) {sharedPreferencesHelper.put("username", name);sharedPreferencesHelper.put("password", pwd);sharedPreferencesHelper.put("isremember", holdPwd.isChecked());} else {
　　　　　　　//如果复选框未被选中则清除记录的账号和密码sharedPreferencesHelper.remove("username");sharedPreferencesHelper.remove("password");sharedPreferencesHelper.remove("isremember");}login.setBackgroundResource(R.drawable.bg_login_submit);login.setTextColor(getResources().getColor(R.color.white));Intent intent = new Intent(LoginActivity.this, MainActivity.class);startActivity(intent);finish();}
}