调整 ASPxGridView 中的分页按钮自定义输出

对于 ASPxGridView,查看其本身功能,是直接读取整个数据库中的表,进行填充,然后内部计算出页数与分页按钮,对于大数据表如果一次性装载数据到内存,那就完蛋了.
我喜欢只抽取一页数据,然后绑定输出.对于如何进行数据分页,只抽取一页数据这里不做讨论!
不知道9版本的这个库,是不是也是一次性读数据的,我并不知道,因为我用的是8这个版本

我抽取一页数据后,发现输出的分页按钮,就是它内部自动计算好的结果,那只能替换这个HTML输出,便于实现自己的分页按钮!
通过分析,ASPxGridView中的分页对象为[ASPxGridViewPager],其ID为[DXBPager],这个是底部的那个按钮,对于表格顶部的是[DXTPager]

代码实现,首先定义一个对象,继承自 ASPxGridView

public sealed partial class DataGrid2X : ASPxGridView
{
    protected override void CreateChildControls()
    {
        base.CreateChildControls();

        ASPxGridViewPager pager = this.FindControl("DXBPager") as ASPxGridViewPager;
        if (pager != null)
            pager.SetRenderMethodDelegate(this.RenderPager2X_Control); //输出的委托
    }


        void RenderPager2X_Control(HtmlTextWriter output, Control container)
        {
            /*用新的类输出HTML*/
            ASPxGridViewPager2X apage = new ASPxGridViewPager2X(this);
            apage.AllButton.Visible = this.FilterValue.Length > 0;
            apage.EnableViewState = false;
            apage.SetPageCount_2X(/*总页数*/);
            apage.SetPageIndex_2X(/*当前页数*/);
            apage.SetItemCount_2X(/*总的记录数*/);
            apage.RenderControl(output);

            //原来考虑从WebDataControllerProvider继承,可放弃
        }
}

public sealed partial class DataGrid2X : ASPxGridView { protected override void CreateChildControls() { base.CreateChildControls(); ASPxGridViewPager pager = this.FindControl("DXBPager") as ASPxGridViewPager; if (pager != null) pager.SetRenderMethodDelegate(this.RenderPager2X_Control); //输出的委托 } void RenderPager2X_Control(HtmlTextWriter output, Control container) { /*用新的类输出HTML*/ ASPxGridViewPager2X apage = new ASPxGridViewPager2X(this); apage.AllButton.Visible = this.FilterValue.Length > 0; apage.EnableViewState = false; apage.SetPageCount_2X(/*总页数*/); apage.SetPageIndex_2X(/*当前页数*/); apage.SetItemCount_2X(/*总的记录数*/); apage.RenderControl(output); //原来考虑从WebDataControllerProvider继承,可放弃 } }  
 

 

ASPxGridViewPager2X是继承自DX库中的[ASPxGridViewPager]类

public class ASPxGridViewPager2X : ASPxGridViewPager
{
 public ASPxGridViewPager2X(DataGrid2X grid)
  : base(grid)
 {

 }


 public override int PageCount
 {
  get
  {
   return _PageCount;// base.PageCount;
  }
 }int _PageCount;

 internal void SetPageCount_2X(int p)
 {
  this._PageCount = p;
 }

 public override int PageIndex
 {
  get
  {
   return _PageIndex;// base.PageIndex;
  }
 }int _PageIndex;

 internal void SetPageIndex_2X(int p)
 {
  this._PageIndex = p;
 }

 public string JScript
 {
  get { return this.Scripts.GetPagerOnClickFunction(this.ID);  }
 }

 /// <summary>
 /// 总记录数
 /// </summary>
 public override int ItemCount
 {
  get
  {
   return _ItemCount;
  }
 }int _ItemCount;

 internal void SetItemCount_2X(int itemCount)
 {
  this._ItemCount = itemCount;
  if (itemCount == 0)
  {
   this._PageIndex = 0;
   this._PageCount = 0;
  }
 }

 protected override string GetItemElementOnClick(string id)
 {
  /*以下替换成自己的JS代码*/
  string btnIDFlag = id.ToUpper();
  switch (btnIDFlag)
  {
   case "PBF":
    return "g2x_doExecPager(1,0);";
   case "PBP":
    return "g2x_doExecPager(2," + (this.PageIndex + 1).ToString() + ");";
   case "PBN":
    return "g2x_doExecPager(3," + (this.PageIndex + 1).ToString() + ");";
   case "PBL":
    return "g2x_doExecPager(4,"+ this.PageCount.ToString() +");";
   case "PBA":
    return "g2x_cancelResult();"; //"ALL"按钮,显示不过滤的记录,主要考虑查询后,取消条件,显示所有数据
  }

  if (btnIDFlag.StartsWith("PN"))
  {
   string pageIdx = btnIDFlag.Replace("PN", "");
   pageIdx = (Convert.ToInt32(pageIdx) + 1).ToString();
   return "g2x_doExecPager(5," + pageIdx + ");";//  + this.Grid.ClientInstanceName + ".GotoPage(0);";
  }

  return string.Empty;

 }



 //public override DevExpress.Web.ASPxPager.SummaryProperties Summary
 //{
 //    get
 //    {
 //        base.Summary.AllPagesText = "xx";
 //        return base.Summary;
 //    }
 //}

}