/// <summary>
/// 保证一次请求只创建一个EF上下文
/// </summary>
/// <returns></returns>
public static DbContext CreateDbContext()
{
DbContext dbContext = CallContext.GetData("dbContext") as DbContext;
if (dbContext == null)
{
dbContext = new LotteryEntities();
CallContext.SetData("dbContext", dbContext);
}
return(dbContext);
}