绑定的GridView有许多记录 [英] Bind GridView with many records

问题描述

我有一个GridView，显示只有50条记录在通过分页的时候。如果我将绑定到一个源说包含150的记录，它的工作原理般的魅力，但是当记录尺寸急剧增加至10,00000，它经历了千百年来加载数据。所以，我想知道的是有刚装50的任何方式在一个时间该可见??记录

  

我想是懒加载或虚拟堆栈的功能
  面板中的WPF。

这就是我如何绑定到GridView -

 私人无效LoadCustomers（）
        {
            如果（高速缓存[CustomersData] == NULL）
            {
                Business.Customers客户= Business.Customers.GetAllCustomer（）;
                缓存[CustomersData] =客户;
            }
            this.customerGridView.DataSource =缓存[CustomersData];
            this.customerGridView.DataBind（）;
        }
 

下面是它获取来自DB-数据的功能。

 公共静态客户GetAllCustomer（INT指数）
        {
            客户的客户=新客户（）;        NShop_SmallEntities数据=新NShop_SmallEntities（）;
        VAR DBCUSTOMERS =（从C在data.Customers
                            选择C）.OrderBy（C =＆GT; c.CustomerId）.Skip（指数* 50）。取（50）;        的foreach（在DBCUSTOMERS VAR dbCustomer）
        {
            customers.Add（Customer.GetCustomer（dbCustomer））;
        }        回报客户;
        }公共静态客户GetCustomer（DAL.Customer dbCustomer）
        {
            返回新客户（）
                {
                    客户ID = dbCustomer.CustomerId，
                    名字= dbCustomer.FirstName，
                    姓氏= dbCustomer.LastName，
                    电子邮件= dbCustomer.Email，
                    DOB = dbCustomer.DOB，
                    市= dbCustomer.City，
                    状态= dbCustomer.State，
                    邮政code = dbCustomer.Postal code，
                    国家= dbCustomer.Country，
                    定单计数= dbCustomer.Orders.Count（）
                };
        }
 

解决方案

下面是，accoring对你的变化，我会怎么做：

 公共静态客户GetAllCustomer（INT的startIndex，诠释nbrOfResults，出总）{
   客户的客户=新客户（）;   NShop_SmallEntities数据=新NShop_SmallEntities（）;
   从data.CustomersÇVAR DBCUSTOMERS =
                     选择C;   // Retreiving客户总数。需要得到
   // ObjectDataSource的工作。
   总= dbCustomers.Count（）;   在DBCUSTOMERS的foreach（VAR dbCustomer
                         .Skip（（的startIndex * nbrOfResults）+1）
                         。取（NumberOfResults）.ToList（）{
      customers.Add（Customer.GetCustomer（dbCustomer））;
   }
   回报客户;
}///＆LT;总结＆gt;
///此方法必须具有比真正的一相同的签名...... exept名称：oP处
///＆LT; /总结＆gt;
公共静态INT GetAllCustomerCount（INT的startIndex，诠释nbrOfResults，出总）{
      返回（从C中选择data.Customers C）.Count之间的（）;
}
 

现在在你的页面;

 ＆LT; ASP：GridView控件ID =gvBulletins=服务器AllowPaging =真
   ObjectDataSourceID =objCustomersDS＆GT;
＆LT; / ASP：GridView的＆GT;＆LT; ASP：ObjectDataSource控件ID =objCustomersDS=服务器
     SelectMethod =GetAllCustomerSelectCountMethod =GetAllCustomerCount
     类型名=的AssemblyNameEnablePaging =真MaximumRowsParameterName =nbrOfResults
     StartRowIndexParameterName =的startIndex＆GT;
    ＆LT; SelectParameters＆GT;
         ＆LT; ASP：参数名称=的startIndexTYPE =的Int32/＆GT;
         ＆LT; ASP：参数名称=nbrOfResultsTYPE =的Int32/＆GT;
         ＆LT; ASP：参数方向=输出NAME =总TYPE =的Int32/＆GT;
    ＆LT; / SelectParameters＆GT;
＆LT; / ASP：ObjectDataSource控件＆GT;
 

I have a GridView which shows only 50 records at a time through paging. If i bind that to a source say containing 150 records, it works like charm but when the record size increases drastically to 10,00000, it took ages to load data.. So, i want to know is there any way of just loading 50 records at a time which are visible??

I want something like Lazy Loading or the feature of Virtualizing Stack Panel in wpf.

This is how i am binding to the GridView -

private void LoadCustomers()
        {            
            if (Cache["CustomersData"] == null)
            {
                Business.Customers customers = Business.Customers.GetAllCustomer();
                Cache["CustomersData"] = customers;
            }
            this.customerGridView.DataSource = Cache["CustomersData"];
            this.customerGridView.DataBind();  
        }

And here's the function which fetch data from DB-

public static Customers GetAllCustomer(int index)
        {
            Customers customers = new Customers();

        NShop_SmallEntities data = new NShop_SmallEntities();
        var dbCustomers = (from c in data.Customers
                            select c).OrderBy(c=> c.CustomerId).Skip(index * 50).Take(50);

        foreach (var dbCustomer in dbCustomers)
        {
            customers.Add(Customer.GetCustomer(dbCustomer));
        }

        return customers;
        }

public static Customer GetCustomer(DAL.Customer dbCustomer)
        {
            return new Customer()
                {
                    CustomerId = dbCustomer.CustomerId,
                    FirstName = dbCustomer.FirstName,
                    LastName = dbCustomer.LastName,
                    Email = dbCustomer.Email,
                    DOB = dbCustomer.DOB,
                    City = dbCustomer.City,
                    State = dbCustomer.State,
                    PostalCode = dbCustomer.PostalCode,
                    Country = dbCustomer.Country,
                    OrderCount = dbCustomer.Orders.Count()
                };
        }

解决方案

Here is, accoring to your change, how I would do that :

public static Customers GetAllCustomer(int startIndex, int nbrOfResults, out total) {
   Customers customers = new Customers();

   NShop_SmallEntities data = new NShop_SmallEntities();
   var dbCustomers = from c in data.Customers
                     select c;

   // Retreiving total number of customers. NEEDED to get 
   // ObjectDataSource working.
   total = dbCustomers.Count();

   foreach (var dbCustomer in dbCustomers
                         .Skip((startIndex * nbrOfResults) + 1)
                         .Take(NumberOfResults).ToList() {
      customers.Add(Customer.GetCustomer(dbCustomer));
   }
   return customers;
}

/// <summary>
/// This methods must have the same signature than the "real" one... exept the name :oP
/// </summary>
public static int GetAllCustomerCount(int startIndex, int nbrOfResults, out total) {
      return (from c in data.Customers select c).Count();
}

And now in your page ;

<asp:GridView ID="gvBulletins" runat="server" AllowPaging="True" 
   ObjectDataSourceID="objCustomersDS">
</asp:GridView>

<asp:ObjectDataSource ID="objCustomersDS" runat="server" 
     SelectMethod="GetAllCustomer" SelectCountMethod="GetAllCustomerCount" 
     TypeName="AssemblyName" EnablePaging="True" MaximumRowsParameterName="nbrOfResults"
     StartRowIndexParameterName="startIndex">
    <SelectParameters>
         <asp:Parameter Name="startIndex" Type="Int32" />
         <asp:Parameter Name="nbrOfResults" Type="Int32" />
         <asp:Parameter Direction="Output" Name="total" Type="Int32" />
    </SelectParameters>
</asp:ObjectDataSource>

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