reflection.cs

C#代码查看Sqlserver等不同数据库的源代码

//=====================================================================================
// 作者：二十四画生
// Email：mailto:[e-mail]
// Blog：http://esshs.cnblogs.com
//=====================================================================================

using System;
using Esshs.Common.Utilities;

namespace Esshs.Common.Framework
{
	/// <summary>
	/// 利用反射动态的创建对象
	/// </summary>
	public class Reflection
	{

		/// <summary>
		/// 根据Provider类型创建对象实例
		/// </summary>
		/// <param name="ObjectProviderType"></param>
		/// <returns></returns>
		public static object CreateObject(string ObjectProviderType)
		{
			return CreateObject(ObjectProviderType, "", "");
		}

		/// <summary>
		/// 根据Provider类型和指定的命名空间和程序集名称创建对象实例
		/// </summary>
		/// <param name="ObjectProviderType"></param>
		/// <param name="ObjectNamespace"></param>
		/// <param name="ObjectAssemblyName"></param>
		/// <returns></returns>
		public static object CreateObject(string ObjectProviderType , string ObjectNamespace, string ObjectAssemblyName)
		{
			string TypeName = "";
			string CacheKey = "";
			ProviderConfiguration objProviderConfiguration = ProviderConfiguration.GetProviderConfiguration(ObjectProviderType);
			if (ObjectNamespace != "" && ObjectAssemblyName != "")
			{
				TypeName = ObjectNamespace + "." + objProviderConfiguration.DefaultProvider + ", " + ObjectAssemblyName + "." + objProviderConfiguration.DefaultProvider;
				CacheKey = ObjectNamespace + "." + ObjectProviderType + "provider";
			}
			else
			{
				TypeName = ((Provider)objProviderConfiguration.Providers[objProviderConfiguration.DefaultProvider]).Type;
				CacheKey = ObjectProviderType + "provider";
			}
			return CreateObject(TypeName, CacheKey);
		}

		/// <summary>
		/// 利用反射动态构建指定TypeName的对象实例，并将创建的对象存到缓存中（利用缓存可减轻由于反射引起的性能损耗）
		/// </summary>
		/// <param name="TypeName"></param>
		/// <param name="CacheKey"></param>
		/// <returns></returns>
		public static object CreateObject(string TypeName, string CacheKey)
		{
			if (CacheKey == "")
			{
				CacheKey = TypeName;
			}

			// 先从缓存中获取该类型
			Type objType = (Type)DataCache.GetCache(CacheKey);

			if (objType == null)
			{
				try
				{
					objType = Type.GetType(TypeName, true);
					// 写入缓存
					DataCache.SetCache(CacheKey, objType);
				}
				catch
				{
					// 记录错误日志
				}
			}

			// 使用与指定参数匹配程度最高的构造函数来创建指定类型的实例
			return Activator.CreateInstance(objType);
		}
	}
}