Paging with DataList Control

DataList is a data bound list control that displays items using certain templates defined at the design time.The content of the DataList control is manipulated by using templates sections such as FooterTemplate, HeaderTemplate, ItemTemplate, SelectedItemTemplate ,AlternatingItemTemplate, EditItemTemplate and SeparatorTemplate

PagedDataSource, is a class that encapsulates the paging related properties for data-bound controls such as DataGrid, GridView, DataList, DetailsView.

Now lets take an Example of Displaying Country on Datalist with Paging

Steps.

1. Create Datalist for Country

<asp:DataList ID="dlCountry" runat="server">
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Eval("Country_Code") %>'></asp:Label>
<asp:Label ID="Label2" runat="server" Text='<%# Eval("Country_Name") %>'></asp:Label>
</ItemTemplate>
</asp:DataList>


<asp:DataList ID=" dlPaging" runat="server" OnItemCommand="dlPaging _ItemCommand">
<ItemTemplate>
<asp:LinkButton ID="lnkbtnPaging" runat="server" CommandArgument='<%# Eval("PageIndex") %>' CommandName="lnkbtnPaging" Text='<%# Eval("PageText") %>'></asp:LinkButton>
</ItemTemplate>
</asp:DataList>



2. now on Code Behind write a method to fetch data from the Country’s table.

private void BindGrid()
{
string sql = "Select * from Country Order By Country_Name";
SqlDataAdapter da = new SqlDataAdapter(sql, “Yourconnectionstring”);
DataTable dt = new DataTable();
da.Fill(dt);

pds.DataSource = dt.DefaultView;
pds.AllowPaging = true;
pds.PageSize = Convert.ToInt16(ddlPageSize.SelectedValue);
pds.CurrentPageIndex = CurrentPage;
lnkbtnNext.Enabled = !pds.IsLastPage;
lnkbtnPrevious.Enabled = !pds.IsFirstPage;

dlCountry.DataSource = pds;
dlCountry.DataBind();

doPaging();
}



3.Call this BindGrid method in the Page load event.

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGrid();
}
}


4.Declare a PagedDataSource object at page scope.
PagedDataSource pds = new PagedDataSource();

5. create new property call CurrentPage to maintain the latest selected page index.
and pu this code on it.

public int CurrentPage
{

get
{
if (this.ViewState["CurrentPage"] == null)
return 0;
else
return Convert.ToInt16(this.ViewState["CurrentPage"].ToString());
}

set
{
this.ViewState["CurrentPage"] = value;
}

}


6.write a method ‘doPaging’ to create a list of page numbers.

private void doPaging()
{
DataTable dt = new DataTable();
dt.Columns.Add("PageIndex");
dt.Columns.Add("PageText");
for (int i = 0; i < pds.PageCount; i++)
{
DataRow dr = dt.NewRow();
dr[0] = i;
dr[1] = i + 1;
dt.Rows.Add(dr);
}

dlPaging.DataSource = dt;
dlPaging.DataBind();
}


7. create new paging event


protected void dlPaging_ItemCommand(object source, DataListCommandEventArgs e)
{
if (e.CommandName.Equals("lnkbtnPaging"))
{
CurrentPage = Convert.ToInt16(e.CommandArgument.ToString());
BindGrid();
}
}


8. Previous And Next Button Events


protected void lnkbtnPrevious_Click(object sender, EventArgs e)
{
CurrentPage -= 1;
BindGrid();
}

protected void lnkbtnNext_Click(object sender, EventArgs e)
{
CurrentPage += 1;
BindGrid();
}


9.Change PageSize Dynamically

protected void ddlPageSize_SelectedIndexChanged(object sender, EventArgs e)
{
CurrentPage = 0;
BindGrid();
}



10.HighLight Selected Page Number


protected void dlPaging_ItemDataBound(object sender, DataListItemEventArgs e)
{
LinkButton lnkbtnPage = (LinkButton)e.Item.FindControl("lnkbtnPaging");
if (lnkbtnPage.CommandArgument.ToString() == CurrentPage.ToString())
{
lnkbtnPage.Enabled = false;
lnkbtnPage.Font.Bold = true;
}
}



view Demo here