This tutorial explains the concept of creating Alphabetical Paging Control in Asp.Net.

Most web applications, which are displaying contents in a grid or list style, includes the Paging Technique, otherwise, the Pager, to reduce the length of the list displayed in a page.On tehcnical aspect it reduces the time taken to load the page in the internet.rom the user perspective, user got the freedom to look at any page, by just click on the desired page numbers to view its content. This tutorial is going to show you, how to create an alphabetic paging control in Asp.Net applications by using a Stored Procedure.

Open an aspx page in your Visual Studio, add a DataList and a GridView control into it. The DataList control is the Pager control, used to display the Page Numbers, in our terms Paging Alphabets and the GridView control is used to display the list of customers from the SQL Server database. First, in the Item Template section of the DataList, add a LinkButton and name it as lnkbtnPaging. Bind the Text and CommandArgument property of the LinkButton with the value as PageText and PageIndex respectively. PageText and PageIndex are the two columns from the DataTable, which we are going to create in the code-behind section to bind with this DataList. This DataTable will have values used for paging. Note that both PageText and PageIndex will have the same value. Then design the GridView control to display columns from the Customer table. For the purpose of this article, we are going to display the Customer Name, Age, Gender and Email Id along with their some date. So the aspx page is ready, now we are going to move on the code-behind section.

In this tutorial, we are going to show you three different methods of creating a Paging control. Lets go one by one.

The first method is to create an alphabetical paging control with alphabets from A to Z. For this we have to loop through 65 to 90, and convert the value to its equivalent character, which is from A to Z. Then store each value into a DataTable row and bind it with the DataList control. The code for this method is given below

private void CreateAlphaPagings()
{
DataTable dt = new DataTable(); 
dt.Columns.Add("PageIndex"); 
dt.Columns.Add("PageText"); 
if (this.ViewState["Paging"] == null) 
{ 
for (int i = 65; i <= 90; i++) 
{ 
DataRow dr = dt.NewRow(); 
dr[0] = Char.ConvertFromUtf32(i); 
dr[1] = Char.ConvertFromUtf32(i); 
dt.Rows.Add(dr); 
} 
DataRow drNew = dt.NewRow(); 
drNew["PageIndex"] = "All"; 
drNew["PageText"] = "All"; 
dt.Rows.Add(drNew); 
this.ViewState["Paging"] = dt; 
}
else 
dt = (DataTable)this.ViewState["Paging"]; 
DataList1.DataSource = dt; 
DataList1.DataBind();
}

The above method creates a DataTable with two columns PageIndex and PageText. We loop through 65 to 90, whose ASCII character equivalent is from A to Z. We are using Char.ConvertFromUtf32 method to convert the number to alphabets. After conversion we assign the value to the PageIndex and PageText columns of the DataTable. Sometimes, the user needs to view all the data in a single page. To provide this option we have added another DataRow with value “All”. We have also used a ViewState variable in this method, in order to avoid the for-loop being executed every time this method is called. So for the first time, when the page loads, the ViewState is empty or null, thus execute the for-loop to create the rows for the DataTable, then the DataTable created will be stored in the ViewState called “Paging”. When this method is called subsequently, the ViewState “Paging” it will supply the alphabetical paging DataTable rows. Finally we bind the DataList is bind with the paging DataTable.

To display the Customer information in a GridView control, we create a method called BindGrid, which takes a parameter called StartAlpha. This parameter is responsible to filter the customer records before binding it with the GridView control. If the parameter value is “All”, then all records will be displayed in the GridView control. The BindGrid method is given below.

private void BindGrid(string StartAlpha)
{
string sql = ""; 
if (StartAlpha == "All") 
sql = "Select * from Customers Order By Cus_Code Desc"; 
else 
sql = "Select * from Customers Where Cus_Name Like '" + StartAlpha 
+ "%' Order By Cus_Code Desc "; 

SqlDataAdapter da = new SqlDataAdapter(sql, "YourConnectionString"); 
DataTable dtSelect = new DataTable(); 
da.Fill(dtSelect); 
GridView1.DataSource = dtSelect; 
GridView1.DataBind();
}

In the page load event, we have to display the pager in the DataList and the Customer information in the GridView control.