Extend the pagination function of the gridview

Using system;
Using system. Collections. Generic;
Using system. collections;
Using system. componentmodel;
Using system. Data;
Using system. text;
Using system. Web;
Using system. Web. UI;
Using system. Web. UI. webcontrols;
Using system. reflection;
Using system. reflection. emit;
Using Microsoft. applicationblocks. Data;

Namespace jdglwebcontrols
{
[Defaultproperty ("selectedvalue")]
[Toolboxdata ("<{0}: supergridview runat = Server> </{0}: supergridview>")]
Public class supergridview: gridview
{
# Region "declaring variables"
Private linkbutton lkfirst;
Private linkbutton lkprev;
Private linkbutton lknext;
Private linkbutton lklast;
Private const string pagerinformation = "Total {0} items total {1} pages current {2} pages per page {3 ";
Private const string pagerinformation2 = "Total {1} current {2} pages per page {3 ";
Private const string not_record_found = "<Div align = center> <B style = color: red;> <br> no record </B> <! -- Design by genson Email: genson_diy # Sina.com --> </div> ";
# Endregion

# Region "Custom Attributes"

/// <Summary>
/// Total number of records
/// </Summary>
[Category ("Custom Attributes")]
[Defaultvalue (-1)]
[Description ("Total number of custom records")]
[Browsable (true)]
Public Virtual int recordcount
{
Get
{
Return viewstate ["recordcount"] = NULL? -1: Convert. toint32 (viewstate ["recordcount"]);
}
Set
{
Viewstate ["recordcount"] = value;
}
}

/// <Summary>
/// The text displayed when the supergridview data is empty
/// </Summary>
Public String emptytext
{
Get
{
Return viewstate ["emptytext"] = NULL? Not_record_found: viewstate ["emptytext"]. tostring ();
}
Set
{
Viewstate ["emptytext"] = value;
}
}

# Endregion

# Region "override method"
Protected override void initializepager (gridviewrow row, int columnspan, pageddatasource)
{

Initializedropdownlist (row, columnspan, pageddatasource );
Createpager (row. cells [0]. Controls );
Getrecordcount ();
Createpagerinformation (row. cells [0]. Controls );

// Base. initializepager (row, columnspan, pageddatasource );
}

Public override object datasource
{
Get
{
Return base. datasource;
}
Set
{
Base. datasource = value;
If (value! = NULL)
{
If (datasource is dataset)
Recordcount = (Dataset) datasource). Tables [0]. Rows. count;
If (datasource is icollection)
Recordcount = (icollection) datasource). count;
If (datasource is datatable)
Recordcount = (datatable) datasource). Rows. count;
If (datasource is dataview)
Recordcount = (dataview) datasource). Table. Rows. count;
}

}
}

Protected override void render (htmltextwriter writer)
{
If (httpcontext. Current! = NULL)
{
If (rows. Count = 0)
Writer. Write (not_record_found );
Else
Base. Render (writer );
}
Else
{
Base. Render (writer );
}
}

# Endregion

# Region "custom method"

# Region "dropdownlist used for page initialization"
Void initializedropdownlist (gridviewrow row, int columnspan, pageddatasource)
{
Dropdownlist DRP = new dropdownlist ();
DRP. autopostback = true;
DRP. selectedindexchanged + = new eventhandler (drp_selectedindexchanged );
Literalcontrol LIC = new literalcontrol ("go ");
For (INT I = 0; I <pageddatasource. pagecount; I ++)
{
Listitem li = new listitem (I + 1). tostring () + "page", I. tostring ());
If (pageindex = I)
Li. Selected = true;
DRP. Items. Add (LI );
}
Tablecell cell = new tablecell ();
Cell. Controls. Add (LIC );
Cell. Controls. Add (DRP );
Cell. columnspan = columnspan;
Row. cells. Add (cell );
}

# Endregion

# Endregion

# Region "Create a paging control"

// Create a paging Control
Public void createpager (controlcollection C)
{

C. Add (New literalcontrol ("& nbsp ;"));
Lkfirst = new linkbutton ();
Lkfirst. ID = "lkfirst ";
Lkfirst. commandname = "page ";
Lkfirst. commandargument = "first ";
Lkfirst. Enabled = true;

Lkfirst. Font. Name = "webdings ";
Lkfirst. Font. size = fontunit. Small;
Lkfirst. forecolor = This. forecolor;
Lkfirst. tooltip = "go to the first page ";
Lkfirst. Text = "7 ";

C. Add (lkfirst );
C. Add (New literalcontrol ("& nbsp ;"));

Lkprev = new linkbutton ();
Lkprev. ID = "lkprev ";
Lkprev. commandname = "page ";
Lkprev. commandargument = "Prev ";
Lkprev. Font. Name = "webdings ";
Lkprev. Font. size = fontunit. Small;
Lkprev. forecolor = This. forecolor;
Lkprev. tooltip = "go to the previous page ";
Lkprev. Text = "3 ";
Lkprev. Enabled = true;
If (this. pageindex = 0) lkprev. Enabled = false;

C. Add (lkprev );
C. Add (New literalcontrol ("& nbsp ;"));

Lknext = new linkbutton ();
Lknext. ID = "lknext ";
Lknext. commandname = "page ";
Lknext. commandargument = "Next ";
Lknext. Font. Name = "webdings ";
Lknext. Font. size = fontunit. Small;
Lknext. forecolor = This. forecolor;
Lknext. tooltip = "go to next page ";
Lknext. Text = "4 ";
Lknext. Enabled = true;
If (pageindex = pagecount-1) lknext. Enabled = false;

C. Add (lknext );
C. Add (New literalcontrol ("& nbsp ;"));

Lklast = new linkbutton ();
Lklast. ID = "lklast ";
Lklast. commandname = "page ";
Lklast. commandargument = "last ";
Lklast. Font. Name = "webdings ";
Lklast. Font. size = fontunit. Small;
Lklast. forecolor = This. forecolor;
Lklast. tooltip = "go to the last page ";
Lklast. Text = "8 ";

C. Add (lklast );
C. Add (New literalcontrol ("& nbsp ;"));

}

# Endregion

# Region ""
Public void gotopage (INT pageindex)
{
Gridviewpageeventargs E = new gridviewpageeventargs (pageindex );
This. pageindex = pageindex;
Onpageindexchanging (E );

}

Private void drp_selectedindexchanged (Object sender, eventargs E)
{
Dropdownlist drppager = (dropdownlist) sender;

Gotopage (Int. parse (drppager. selectedvalue ));
}

# Endregion

# Region "create paging information"

// Format: 13 in total, 1 page, current 1 page
Public void createpagerinformation (controlcollection C)
{
Literalcontrol lc0 = new literalcontrol ("");
C. Add (lc0 );
Literalcontrol lc = new literalcontrol ();
If (recordcount! =-1)
{
LC. Text = string. Format (pagerinformation, recordcount, pagecount, pageindex + 1, pagesize );
}
Else
{
LC. Text = string. Format (pagerinformation2, null, pagecount, pageindex + 1, pagesize );
}

C. Add (LC );
}

# Endregion

# Region "reflection"

Private void getrecordcount ()
{
If (! Allowpaging) return;
If (! String. isnullorempty (performanceid ))
{
Try
{
Control C = This. namingcontainer;
Control datasource = C. findcontrol (performanceid );
If (datasource is performancecontrol)
{
Performancecontrol DSC = datasource as performancecontrol;
If (DSC is sqldatasource)
{
Sqldatasource SDS = DSC as sqldatasource;
Commandtype type = commandtype. storedprocedure;
If (SDS. selectcommandtype = sqlperformancecommandtype. Text)
{
Type = commandtype. text;
}
Datatable dt = sqlhelper. executedataset (SDS. connectionstring, type, SDS. selectcommand). Tables [0];
Recordcount = DT. Rows. count;
}

If (DSC is objectdatasource)
{
// Objectdatasource ODS = DSC as objectdatasource;
// If (ODS. enablepaging)
//{
// Throw new notsupportedexception ("Super does not support pagination with the objectdatasource attribute enablepaging = true ");
//}
// Else
//{
// Type typebll = type. GetType (ODS. typename );
// Typebll. invokemember (ODS. selectmethod, bindingflags. declaredonly | bindingflags. Static
// | Bindingflags. invokemethod | bindingflags. Public, null, null, new object [] {string. Empty });
/// Methodinfo method = typebll. getmethod (ODS. selectmethod );
//}
}
}
}
Catch (exception ex)
{
// Throw ex;
}
}
}
# Endregion
}
}