ASP.NET2.0 GridView控件两大常见问题解决方案：自定义数据分页，类似DataGrid的VirtualItemCount功能

        GridView是asp.net2.0新推出的控件，用来取代DataGrid。对于很多简单操作，的确方便了不少，例如不写一句代码结合sqldatasource实现增删改、翻页等操作。

        但在很多细粒度的控制方面，反而不如DataGrid，所以大部分时间，笔者依然采用DataGrid，近日重写GridView控件，研究了一下如果通过GridView实现自定义数据分页，成功解决了这个问题。

        GridView分页功能比DataGrid强大了不少，但没有类似dataGrid的VirtualItemCount属性，如何实现自定分页成了难题，翻阅若干资料，终于找到了ObjectDataSource这个对象辅助完成的解决办法，经过改造，成功实现了想要的功能。现把实现思路给大家讲一讲：  

定义适配器类    

     internal class ObjectDataSourceAdapter

 {    

     private object _dt;       

  private int _vic;

        //this is the constructor that takes as parameters a cute little datatable       

  // with the right 10 records, an an integer vic = virtualitemcount      

   public ObjectDataSourceAdapter(object dt, int vic)     

    {

             _dt = dt;         

    _vic = vic;     

    }

        //this returns the datatable (10 records)        

public object GetData()       

  {

            return _dt;  

       }

        //this returns the total number of records in the table (30.000)      

   public int VirtualItemCount()     

    {

             return _vic;  

       }

        //this also returns the datatable (10 records) but the ODS needs it for paging purposes        

 public object GetData(int startRow, int maxRows)  

       {   

          return _dt;  

       }

 }

 

设置ObjectDataSource为数据源

                ObjectDataSource ods = new ObjectDataSource();

                ods.ID = "ods" ;

                ods.EnablePaging = this.AllowPaging; //the paging of ODS depends on the paging of the GridView                

ods.TypeName = "ObjectDataSourceAdapter"; //be sure to prefix the namespace of your application !!! e.g. MyApp.MyTableAdapter                

 ods.SelectMethod = "GetData";                

ods.SelectCountMethod = "VirtualItemCount";               

  ods.StartRowIndexParameterName = "startRow";         

        ods.MaximumRowsParameterName = "maxRows";        

         ods.EnableViewState = false;                

ods.ObjectCreating += new ObjectDataSourceObjectEventHandler(ods_ObjectCreating);

                this.DataSource = ods;              

   this.DataBind();

委托方法

        private void ods_ObjectCreating(object sender, ObjectDataSourceEventArgs e)    

     {          

   e.ObjectInstance = new ObjectDataSourceAdapter(dt, this.RecordCount);

        }

 

这里的dt就是你的分页数据，支持datatable和datareader RecordCount就是VirtualItemCount