Pass Multiple Values from a GridView to Another Page using ASP.NET

Step 1: Create a new ASP.NET website. Drag and drop a SqlDataSource Control to the page and use the wizard to connect to the Northwind database. Select the CustomerId, CompanyName, ContactName, Address and City from the Customers table. The wizard will also prompt you to save the connection string in the web.config file. Choose to do so
SelectCommand="SELECT [CustomerID], [CompanyName], [ContactName], [Address], [City] FROM [Customers]">
An entry will be added to the web.config file as shown below:
connectionStrings
add name="NorthwindConnectionString" connectionString="Data Source=(local);Initial Catalog=Northwind;Integrated Security=True"providerName="System.Data.SqlClient"

Step 2: Now add a GridView control to the page and using the smart tag, select the DataSource to be SqlDataSource1 in the GridView tasks panel. Using the same panel, click on the Enable Paging and Enable Sorting checkboxes. The source will look similar to the following. Observe that the DataKeyNames is set to ‘CustomerId’, that is the primary key of the Customers table.
asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="CustomerID" DataSourceID="SqlDataSource1" AllowPaging="True" AllowSorting="True"
Columns
asp:BoundField DataField="CustomerID" HeaderText="CustomerID" ReadOnly="True" SortExpression="CustomerID"
asp:BoundField DataField="CompanyName" HeaderText="CompanyName" SortExpression="CompanyName"
asp:BoundField DataField="ContactName" HeaderText="ContactName" SortExpression="ContactName"
asp:BoundField DataField="Address" HeaderText="Address" SortExpression="Address"
asp:BoundField DataField="City" HeaderText="City" SortExpression="City"
Columns
asp:GridView

Step 3: We will now add another page in our project. In the Solution Explorer, right click the project > Add New Item > Web Form > Rename it to ‘CustomerDetails.aspx’.

Step 4: Go back to Default.aspx and add two hyperlink fields. We will see how to pass a single value as well as multiple values using the two hyperlink fields.
Single Value:
Add the following hyperlink control after the tag in the GridView as shown below:
Columns
asp:HyperLinkField DataNavigateUrlFields="CustomerID" DataNavigateUrlFormatString="CustomerDetails.aspx?CID={0}" Text="Pass Single Value"
Multiple Values:
Just below the first hyperlink field, add another hyperlink field as shown below:
asp:HyperLinkField DataNavigateUrlFields="CustomerID, CompanyName, ContactName, Address, City" DataNavigateUrlFormatString="CustomerDetails.aspx?CID={0}&CName={1}&ContactName={2}&Addr={3}&City={4}" Text="Pass Multiple Values"

In the source code shown above, we are using the hyperlink field and setting some properties that will make it extremely easy to pass values to a different page. The 'DataNavigateUrlFields' sets the names of the fields, that is to be used to construct the URL in the HyperLinkField. In the first hyperlink, since we are passing only a single value, the DataNavigateUrlFields contains only CustomerID. However in the second hyperlink, since there are multiple values to be passed, DataNavigateUrlFields contains all the names of the fields that are to be passed as query string to CustomerDetails.aspx
Similarly, the 'DataNavigateUrlFormatString' sets the string that specifies the format in which the URL is to be created. The 'Text' property represents the text that will be displayed to the user. The entire source code will look similar to the following:
SelectCommand="SELECT [CustomerID], [CompanyName], [ContactName], [Address], [City] FROM [Customers]"
asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="CustomerID" DataSourceID="SqlDataSource1" AllowPaging="True" AllowSorting="True"
Columns
asp:HyperLinkField DataNavigateUrlFields="CustomerID"
DataNavigateUrlFormatString="CustomerDetails.aspx?CID={0}"
Text="Pass Single Value"
asp:HyperLinkField DataNavigateUrlFields="CustomerID, CompanyName, ContactName, Address, City"
DataNavigateUrlFormatString="CustomerDetails.aspx?CID={0}&CName={1}&ContactName={2}&Addr={3}&City={4}"
Text="Pass Multiple Values"
asp:BoundField DataField="CustomerID" HeaderText="CustomerID" ReadOnly="True" SortExpression="CustomerID"
asp:BoundField DataField="CompanyName" HeaderText="CompanyName" SortExpression="CompanyName"
asp:BoundField DataField="ContactName" HeaderText="ContactName" SortExpression="ContactName"
asp:BoundField DataField="Address" HeaderText="Address" SortExpression="Address"
asp:BoundField DataField="City" HeaderText="City" SortExpression="City"
Columns
asp:GridView

Step 5: The last step is to retrieve the query string variables from the URL in the CustomerDetails.aspx page. Add the following code for that:
C#
protected void Page_Load(object sender, EventArgs e)
{
string cid = Request.QueryString["CID"];
string cname = Request.QueryString["CName"];
string contactName = Request.QueryString["ContactName"];
string address = Request.QueryString["Addr"];
string city = Request.QueryString["City"];
}
VB.NET
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
Dim cid As String = Request.QueryString("CID")
Dim cname As String = Request.QueryString("CName")
Dim contactName As String = Request.QueryString("ContactName")
Dim address As String = Request.QueryString("Addr")
Dim city As String = Request.QueryString("City")
End Sub
Set a breakpoint at the Page_Load method of the CustomerDetails.aspx. Run the application and click on either the ‘Pass Single Value’ or ‘Pass Multiple Values’ hyperlink to pass values to the CustomerDetails.aspx page. Using the breakpoint, observe the values of the selected row being passed to the CustomerDetails page.