基于数据库的多语言解决方案

1、简介

开发的系统中，有些页面上的文字不同的用户可能想显示的内容不同，还有用户添加的菜单需要多语言支持，微软提供的resource文件不能很好地解决（用户没法根据自己的需要修改文字），所以采用基于数据库的多语言。

2、设计思路

1、数据表结构

      语言表

   1:  CREATE TABLE [dbo].[T_LANGUAGE](

   2:      [VALUE] [varchar](50) NOT NULL,

   3:      [NAME] [varchar](50) NOT NULL,

   4:      [STATUS] [varchar](10) NOT NULL

   5:  ) ON [PRIMARY]

   6:   

   7:  GO

   8:   

   9:  ALTER TABLE [dbo].[T_LANGUAGE] ADD  CONSTRAINT [DF_T_LANGUAGE_Status]  DEFAULT ((1)) FOR [STATUS]

  10:  GO

  11:   

  键值对表

  12:  CREATE TABLE [dbo].[T_KEY_VALUE](

  13:      [KEY] [varchar](50) NOT NULL,

  14:      [LANGUAGE_VALUE] [varchar](50) NOT NULL,

  15:      [SYSTEM_NAME] [varchar](50) NOT NULL,

  16:      [VALUE] [varchar](500) NULL

  17:  ) ON [PRIMARY]

2、工作方式

在程序加载时，把数据库中的多语言键值对同时加载到内存中，用一个字典存储。当需要用到键值对时，直接从字典中获取。

如果键值对发生改变，则重新加载数据库中的所有键值对。

 

3、核心部分代码

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Web;
using FluentData;
namespace SureSoft.Utility
{
    public class LangInstance
    {
        static LangInstance()
        {
            LangInstance.Conifg = new LanguageConfig();
        }
        public static LanguageConfig Conifg { get; set; }
        private static Language _Lang;
        public static Language Lang { get { return _Lang; } }
        public static void Start()
        {
            if (string.IsNullOrWhiteSpace(LangInstance.Conifg.SystemName))
            {
                throw new Exception("系统名称不能为空");
            }
            string systemName = LangInstance.Conifg.SystemName;
            LangInstance.Conifg = ConfigManage.LanguageConfig;
            LangInstance.Conifg.SystemName = systemName;
            if (LangInstance.Conifg.GetLanguage == null)
            {
                LangInstance.Conifg.GetLanguage = () =>
                {
                    if (HttpContext.Current.Session["Language"] == null || string.IsNullOrEmpty(HttpContext.Current.Session["Language"].ToString()))
                    {
                        return HttpContext.Current.Request.UserLanguages[0];
                    }
                    else
                    {
                        return HttpContext.Current.Session["Language"].ToString();
                    }
                };
            }
            _Lang = new Language(LangInstance.Conifg);
        }
        public static void ReStart()
        {
            Start();
        }
        public static void Start(LanguageConfig config)
        {
            LangInstance.Conifg = config;
            Start();
        }
    }
    public class LanguageNameValuePair
    {
        public string Name { get; set; }
        public string Value { get; set; }
    }
    public class Language
    {
        public LanguageConfig Config { get; set; }
        private IDbContext _Db;
        private IDbContext Db
        {
            get
            {
                _Db = new DbContext().ConnectionString(Config.ConnectionString, Config.DbProviderType);
                return _Db;
            }
        }
        private Dictionary<string, Dictionary<string, string>> _KeyValue;
        public Language(LanguageConfig config)
        {
            Config = config;
            _KeyValue = new Dictionary<string, Dictionary<string, string>>();

            //加载多语言资源
            List<string> langs = new List<string>();
            DataTable dt = Db.Sql(string.Format(@"select [key]{0}
                                                    from T_KEY_VALUE
                                                    where SYSTEM_NAME='{1}'
                                                    group by [KEY]", GetLangColumn(ref langs), config.SystemName))
                            .QueryDataTable();
            foreach (DataColumn column in dt.Columns)
            {
                if (column.ColumnName.ToUpper() == "KEY")
                    continue;

                Dictionary<string, string> dic;
                if (!_KeyValue.TryGetValue(column.ColumnName,out dic))
                {
                    dic = new Dictionary<string, string>();
                    _KeyValue.Add(column.ColumnName, dic);
                }
                foreach (DataRow row in dt.Rows)
                {
                    if (dic.ContainsKey(row["key"].ToString()))
                    {
                        dic[row["key"].ToString()] = row[column.ColumnName].ToString();
                    }
                    else
                    {
                        dic.Add(row["key"].ToString(), row[column.ColumnName].ToString());
                    }
                }
            }


        }
        private string GetLangColumn(ref List<string> langs)
        {
            string sql = "";
            DataTable dt = Db.Sql("select * from T_Language where status='1'").QueryDataTable();
            if (dt != null && dt.Rows.Count > 0)
            {
                foreach (DataRow item in dt.Rows)
                {
                    sql += string.Format(",MAX(case LANGUAGE_VALUE when '{0}' then VALUE else '' end) as '{0}'",item["value"]);
                    langs.Add(item["value"].ToString());
                }
            }
            return sql;
        }
        public List<LanguageNameValuePair> GetLanguageList()
        {
            List<LanguageNameValuePair> list = null;
            DataTable dt = Db.Sql("select * from T_Language where status='1'").QueryDataTable();
            if (dt != null && dt.Rows.Count > 0)
            {
                list = new List<LanguageNameValuePair>();
                foreach (DataRow item in dt.Rows)
                {
                    list.Add(new LanguageNameValuePair() { Name = item["name"].ToString(), Value = item["value"].ToString() });
                }
            }
            return list;
        }
        public string this[string key]
        {
            get
            {
                return _KeyValue[Config.GetLanguage().ToUpper()][key];
            }
        }
    }
}

4、使用说明

开启服务端：

LangInstance.Start(new LanguageConfig() { SystemName = "a", ConnectionString = "Data Source=.;Initial Catalog=test;User ID=sa;Password=123456", DbProviderType = FluentData.DbProviderTypes.SqlServer, GetLanguage = null });
LangInstance.Start();

客户端调用：

//添加按钮上的文字显示
btnAdd.Text = LangInstance.Lang["add"];