DBDriverDB的驱动，通过反射获得SQLiteHelper

2017-02-21 22:44:48 访问(1462) 赞(0) 踩(0)

using System;
using System.Collections.Generic;
using System.Text;
using SlowX.IDALDBHelper;
using System.Configuration;
using System.Reflection;
using System.IO;

namespace SlowX.DAL.DLLDriver
{
    /// <summary>
    /// DB的驱动，通过反射获得SQLiteHelper
    /// </summary>
    public class DBDriver
    {

        /// <summary>
        /// 获得DLL的根目录
        /// </summary>
        /// <returns></returns>
        private static string GetRootPath()
        {
            Assembly ass = typeof(DBDriver).Assembly;

            FileInfo theInfo = new FileInfo(ass.Location);

            string theResult = theInfo.Directory.FullName;

            theInfo = null;

            return theResult;
        }

        /// <summary>
        /// 通过反射创建类对象
        /// </summary>
        protected static IDataBaseHelper m_SQLiteHelper = SQLiteHelperCreate();

        /// <summary>
        /// 通过反射创建类对象
        /// </summary>
        /// <returns></returns>
        private static IDataBaseHelper SQLiteHelperCreate()
        {
            // 比如
            // ~/SlowX.SQLiteX86Helper.dll
            string strDLL = ConfigurationManager.AppSettings["SlowX.DAL.DLLDriver.DBDriver.SQLiteHelper.DLL"];

            // SlowX.SQLiteX86Helper.DBHelper
            string TypeName = ConfigurationManager.AppSettings["SlowX.DAL.DLLDriver.DBDriver.SQLiteHelper.TypeName"];

            if (strDLL == null || strDLL.Length == 0)
                return null;

            if(TypeName==null||TypeName.Length ==0)
                return null;

            if (strDLL.StartsWith("~/"))
                strDLL = GetRootPath() + "\\" + strDLL.Substring(2);

            if (!File.Exists(strDLL))
            {

                throw new Exception
                    (
                        "方法："
                        + MethodBase.GetCurrentMethod().ReflectedType.FullName
                        + " "
                        + MethodBase.GetCurrentMethod().ToString()
                        + " 发生异常："
                        + "文件（" + strDLL + "）不存在。"

                    );
            }

            Assembly ass = Assembly.LoadFile(strDLL);

            Type theType = ass.GetType(TypeName);

            if (theType == null)
            {
                throw new Exception
                    (
                        "方法："
                        + MethodBase.GetCurrentMethod().ReflectedType.FullName
                        + " "
                        + MethodBase.GetCurrentMethod().ToString()
                        + " 发生异常："
                        + "反射没有找到类（" + TypeName + "）"

                    );
            }

            return ass.CreateInstance(theType.FullName) as IDataBaseHelper;

        }

        /// <summary>
        /// 设置SQLiteHelper
        /// </summary>
        /// <param name="theValue"></param>
        public static void SQLiteHelperSet(IDataBaseHelper theValue)
        {
            m_SQLiteHelper = theValue;
        }

        /// <summary>
        /// 
        /// </summary>
        public static IDataBaseHelper SQLiteHelper
        {
            get
            {
                return m_SQLiteHelper;
            }
        }

        /// <summary>
        /// 
        /// </summary>
        public DBDriver()
        {

        }
    }
}