public ActionResult Index(string k, string c = "", int page = 1, int pageSize = 15)
{
int count;
count = 0;
//使用缓存搜索
var query = new CRL.ExpressionJoin <Product>(BLL.ProductManage.Instance.AllCache, b => b.ProductStatus == CRL.Package.Product.ProductStatus.已上架);
if (!string.IsNullOrEmpty(k))
{
query.And(b => b.ProductName.Contains(k));
}
if (!string.IsNullOrEmpty(c))
{
query.And(b => b.CategoryCode.StartsWith(c));
}
var products = query.ToList().OrderByDescending(b => b.Id);
count = products.Count();
var result = products.Skip((page - 1) * pageSize).Take(pageSize).ToList();
var pageObj = new PageObj <Product>(result, page, count, pageSize);
return(View(pageObj));
}
protected void Button3_Click(object sender, EventArgs e)
{
var list = Code.ProductDataManage.Instance.AllCache;//指定一个数据源
#region 常规查找 多次计算和内存操作,增加成本
var list2 = list.Where(b => b.Id > 0);//执行一次内存查找
bool a = false;
if (a)
{
list2 = list.Where(b => b.Number > 10);//执行第二次内存查找
}
#endregion
#region 优化后查找 只需一次
var query = new CRL.ExpressionJoin <Code.ProductData>(list, b => b.Id > 0);
if (a)
{
query.And(b => b.Number > 10); //and 一个查询条件
}
list2 = query.ToList(); //返回查询结果 只作一次内存查找
#endregion
}