public DataTable StartPage()
{
if (this.pageCount == 0)
{
return(null);
}
this.statusStackBackWard.Clear();
this.statusStackForward.Clear();
string select = this.ConstructSelectString(true, true, null);
DataSet ds = this.adoBase.DoQuery(select);
PageStatus sta = new PageStatus();
sta.curIDValueEnd = ds.Tables[0].Rows[ds.Tables[0].Rows.Count - 1]["ID"].ToString();
sta.preIDValueHead = ds.Tables[0].Rows[0]["ID"].ToString();
sta.curTable = ds.Tables[0];
this.statusStackForward.Push(sta);
this.curPageIndex = 0;
this.currentPage = sta.curTable;
this.ActivePageIndexChanged(this.curPageIndex);
return(this.currentPage);
}
private string ConstructSelectString(bool first, bool forward, PageStatus curSta)
{
if (this.curParas.Ascending)
{
if (first)
{
return(this.curParas.SelectString);
}
string comp = " >= ";
string curIDValue = curSta.preIDValueHead;
if (forward)
{
comp = " > ";
curIDValue = curSta.curIDValueEnd;
}
if (-1 == this.curParas.SelectString.IndexOf("where"))
{
return(this.curParas.SelectString + string.Format(" where {0} {1} '{2}'", this.curParas.ComplexIDName, comp, curIDValue));
}
return(this.curParas.SelectString + string.Format(" and {0} {1} '{2}'", this.curParas.ComplexIDName, comp, curIDValue));
}
else
{
if (first)
{
return(string.Format(this.curParas.SelectString + " order by {0} desc ", this.curParas.ComplexIDName));
}
string comp = " <= ";
string curIDValue = curSta.preIDValueHead;
if (forward)
{
comp = " < ";
curIDValue = curSta.curIDValueEnd;
}
if (-1 == this.curParas.SelectString.IndexOf("where"))
{
return(this.curParas.SelectString + string.Format(" where {0} {1} '{2}' order by {0} desc", this.curParas.ComplexIDName, comp, curIDValue));
}
return(this.curParas.SelectString + string.Format(" and {0} {1} '{2}' order by {0} desc", this.curParas.ComplexIDName, comp, curIDValue));
}
}
public DataTable PrePage()
{
if (this.curPageIndex < 1)
{
return(null);
}
PageStatus oldSta = (PageStatus)this.statusStackForward.Pop();
this.statusStackBackWard.Push(oldSta);
if (this.preForward)
{
if (this.statusStackForward.Count > 0)
{
oldSta = (PageStatus)this.statusStackForward.Pop();
this.statusStackBackWard.Push(oldSta);
}
}
return(this.ReturnCurrentPage(oldSta.curTable, false));
}
public DataTable NextPage()
{
if (this.curPageIndex >= this.pageCount - 1)
{
return(null);
}
if (this.statusStackBackWard.Count > 0)
{
PageStatus staRes = (PageStatus)this.statusStackBackWard.Pop();
this.statusStackForward.Push(staRes);
if (!this.preForward)
{
if (this.statusStackBackWard.Count > 0)
{
staRes = (PageStatus)this.statusStackBackWard.Pop();
this.statusStackForward.Push(staRes);
}
}
return(this.ReturnCurrentPage(staRes.curTable, true));
}
PageStatus curSta = (PageStatus)this.statusStackForward.Peek();
string select = this.ConstructSelectString(false, true, curSta);
DataSet ds = this.adoBase.DoQuery(select);
PageStatus sta = new PageStatus();
sta.curIDValueEnd = ds.Tables[0].Rows[ds.Tables[0].Rows.Count - 1]["ID"].ToString();
sta.preIDValueHead = curSta.curTable.Rows[0]["ID"].ToString();
sta.curTable = ds.Tables[0];
this.statusStackForward.Push(sta);
return(this.ReturnCurrentPage(sta.curTable, true));
}