SharedPreferences 用法

private void getUserInfoFromPref(){

/*
 * 保存到文件的方法
 *
 *          Constant.user = (User)Constant.readObjectFromFile(Constant.USER_SAVE_PATH);
 */
         //获取到sharepreference 对象， 参数一为xml文件名，参数为文件的可操作模式
        SharedPreferences preferences = this.getSharedPreferences(
                Constant.PREF_FILE_NAME, MODE_APPEND);
        //获取到编辑对象
        String UserId = preferences.getString("UserId","");
        String UserName = preferences.getString("UserName","");
        String UserPho = preferences.getString("UserPho","");
        String UserQRCode = preferences.getString("UserQRCode","");
        String PhotoPath = preferences.getString("PhotoPath","");
        boolean hasLogined = preferences.getBoolean("hasLogined",false);

        Constant.user = new User(UserId,UserName,UserPho,UserQRCode,PhotoPath,hasLogined);
    }

//保存数据 到sharePreference文件
    private void setUserInfoToPref(){
/*
 * 文件的方法
 *
 * File file = new File("/sdcard/myImage/");

        if(!file.exists()){
              file.mkdirs();// 创建文件夹
         }
        Constant.writeObjectToFile(Constant.USER_SAVE_PATH,Constant.user);
        Log.e("user ---",Constant.readObjectFromFile(Constant.USER_SAVE_PATH).toString());
 *
*/

       SharedPreferences preferences = getSharedPreferences(
               Constant.PREF_FILE_NAME, MODE_PRIVATE);
       SharedPreferences.Editor editor = preferences.edit();

       if(Constant.user != null){
           editor.putString("UserId",Constant.user.UserId);
           editor.putString("UserName",Constant.user.UserName);
           editor.putString("UserPho",Constant.user.UserPho);
           editor.putString("UserQRCode",Constant.user.UserQRCode);
           editor.putString("PhotoPath",Constant.user.PhotoPath);
           editor.putBoolean("hasLogined",Constant.user.hasLogined);
       }

       editor.commit();
    }