C# 工厂单例

public class BusinessFactory
{
private static BusinessFactory instance = null;
private static readonly object syncObj = new object();

/// <summary>
/// 业务逻辑创建工厂实例
/// </summary>
public static BusinessFactory Instance
{
get
{
if (instance == null)
{
lock (syncObj)
{
if (instance == null)
{
instance = new BusinessFactory();
}
}
}

return instance;
}
}

//下边定义方法来产生你的业务逻辑实体

#region"个人事务--大事记管理"
/// <summary>
/// 个人事务
/// 公司大记事
/// </summary>
/// <returns></returns>
public ICompanyBigEventBLL CreateCompanyBigEvent()
{
return new CompanyBigEventBLL();
}