Nested GridView Example In Asp.Net With Expand Collapse

This example shows how to create Nested GridView In Asp.Net Using C# And VB.NET With Expand Collapse Functionality.
I have used JavaScript to Create Expandable Collapsible Effect by displaying Plus Minus image buttons.

Customers and Orders Table ofNorthwind Database are used to populate nested GridViews. 

Drag and place SqlDataSource from toolbox on aspx page and configure and choose it as datasource from smart tags 

Go to HTML source of page and add 2 TemplateField in <Columns>, one as first column and one as last column of gridview.

Place another grid in last templateField column.

Markup of page after adding both templatefields will like as shown below. 



HTML SOURCE

---

   1:  <asp:GridView ID="gvMaster" runat="server" 

   2:                AllowPaging="True" 

   3:                AutoGenerateColumns="False" 

   4:                DataKeyNames="CustomerID" 

   5:                DataSourceID="SqlDataSource1" 

   6:                onrowdatabound="gvMaster_RowDataBound">

   7:  <Columns>

   8:  <asp:TemplateField>

   9:      <ItemTemplate>

  10:      <a href="javascript:collapseExpand('customerID-

  11:               <%# Eval("CustomerID") %>');">

  12:      <img id="imagecustomerID-<%# Eval("CustomerID") %>" 

  13:           alt="Click to show/hide orders" 

  14:           border="0" src="plus.png" /></a>

  15:      </ItemTemplate>

  16:  </asp:TemplateField>

  17:  <asp:BoundField DataField="CustomerID" 

  18:                  HeaderText="CustomerID"/>

  19:  <asp:BoundField DataField="CompanyName" 

  20:                  HeaderText="CompanyName"/>

  21:   

  22:  <asp:TemplateField>

  23:  <ItemTemplate>

  24:  <tr><td colspan="100%">

  25:  <div id="customerID-<%# Eval("CustomerID") %>" 

  26:       style="display:none;

  27:       position:relative;left:25px;">

  28:       

  29:  <asp:GridView ID="nestedGridView" runat="server" 

  30:                AutoGenerateColumns="False" 

  31:                DataKeyNames="OrderID">

  32:  <Columns>

  33:  <asp:BoundField DataField="OrderID" HeaderText="OrderID"/>

  34:  <asp:BoundField DataField="OrderDate" HeaderText="OrderDate"/>

  35:  <asp:BoundField DataField="Freight" HeaderText="Freight"/>

  36:  </Columns>

  37:  </asp:GridView>

  38:  </div>

  39:  </td></tr>

  40:  </ItemTemplate>

  41:  </asp:TemplateField>

  42:  </Columns>

  43:  </asp:GridView>

  44:   

  45:  <asp:SqlDataSource ID="SqlDataSource1" runat="server" 

  46:  ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 

  47:  SelectCommand="SELECT [CustomerID], [CompanyName] 

  48:                 FROM [Customers]">

  49:  </asp:SqlDataSource>

Add following JavaScript in head section of page.

---

01<script type="text/javascript">

02function collapseExpand(obj)

03{

04  var gvObject = document.getElementById(obj);

05  var imageID = document.getElementById('image' + obj);

06 

07  if (gvObject.style.display == "none")

08      {

09         gvObject.style.display = "inline";

10         imageID.src = "minus.png";

11      }

12  else

13     {

14         gvObject.style.display = "none";

15         imageID.src = "plus.png";

16     }

17}

18</script>

Write following code in RowDataBound Event of parent Grid to populate nested gridview.

C#

---

01protected void gvMaster_RowDataBound(object sender, GridViewRowEventArgs e)

02    {

03        if (e.Row.RowType == DataControlRowType.DataRow)

04        {

05            string customerID = Convert.ToString(DataBinder.Eval(e.Row.DataItem, "CustomerID"));

06            GridView gvChild = (GridView)e.Row.FindControl("nestedGridView");

07            SqlDataSource gvChildSource = new SqlDataSource();

08            gvChildSource.ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

09            gvChildSource.SelectCommand = "SELECT [OrderID], [OrderDate],[Freight] FROM [Orders] WHERE [CustomerID] = '" + customerID + "'";

10            gvChild.DataSource = gvChildSource;

11            gvChild.DataBind();

12        }

13    }

VB.NET

---

01Protected Sub gvMaster_RowDataBound(sender As Object, e As GridViewRowEventArgs)

02 If e.Row.RowType = DataControlRowType.DataRow Then

03  Dim customerID As String = Convert.ToString(DataBinder.Eval(e.Row.DataItem, "CustomerID"))

04  Dim gvChild As GridView = DirectCast(e.Row.FindControl("nestedGridView"), GridView)

05  Dim gvChildSource As New SqlDataSource()

06  gvChildSource.ConnectionString = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString

07  gvChildSource.SelectCommand = "SELECT [OrderID], [OrderDate],[Freight] FROM [Orders] WHERE [CustomerID] = '" + customerID + "'"

08  gvChild.DataSource = gvChildSource

09  gvChild.DataBind()

10 End If

11End Sub