[SOLVED] Dropdownlist SelectedIndexChanged (OnSelectedIndexChanged) From GridView

You may want to implement some functionality on changing index of a drop down list which is provided within a grid for multi records. I too had to do the same and searched over internet for some suitable solution. Though there are more than one solutions but the solution I am providing is most easy of them and requires no tricks.
The Solution
Note the RED BOLD code of HTML view, which means you will have to set EnableViewState="false" for the griview and also you will have to set AutoPostBack="true" for the dropdownlist.

Here is your GridView code (The HTML)


<asp:GridView runat="server" ID="gvTest" Width="50%" AutoGenerateColumns="false" EnableViewState="false">
            <Columns>
                <asp:BoundField DataField="Gender" HeaderText="Gender" HeaderStyle-HorizontalAlign="Left" />
                <asp:TemplateField >
                    <ItemTemplate>
                        <asp:DropDownList ID="ddlTest" AutoPostBack="true" runat="server" OnSelectedIndexChanged="ddlTest_SelectedIndexChanged">
                            <asp:ListItem Value="Male">Male</asp:ListItem>
                            <asp:ListItem Value="Female">Female</asp:ListItem>
                        </asp:DropDownList>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>


And here is Code behind 
1. C#

protected void Page_Load(object sender, System.EventArgs e)

{

       try {

              FillGridView();

       } catch (Exception ex) {

              Response.Write(ex.Message);

       }

}

private void FillGridView()

{

       try {

              DataTable dt = new DataTable();

              dt.Columns.Add("Gender");

              DataRow dr = null;

              dr = dt.NewRow();

              dr["Gender"] = "I am a ";

              dt.Rows.Add(dr);

              gvTest.DataSource = dt;

              gvTest.DataBind();

       } catch (Exception ex) {

              Response.Write(ex.Message);

       }

}

protected void ddlTest_SelectedIndexChanged(object sender, System.EventArgs e)

{

       try {

              Response.Write("You selected " + ((DropDownList)sender).SelectedItem.Value);

       } catch (Exception ex) {

              Response.Write(ex.Message);

       }

}

2. VB.Net

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load

        Try

            FillGridView()

        Catch ex As Exception

            Response.Write(ex.Message)

        End Try

    End Sub

    Private Sub FillGridView()

        Try

            Dim dt As New DataTable

            dt.Columns.Add("Gender")

            Dim dr As DataRow

            dr = dt.NewRow

            dr("Gender") = "I am a "

            dt.Rows.Add(dr)

            gvTest.DataSource = dt

            gvTest.DataBind()

        Catch ex As Exception

            Response.Write(ex.Message)

        End Try

    End Sub

    Protected Sub ddlTest_SelectedIndexChanged(sender As Object, e As System.EventArgs)

        Try

            Response.Write("You selected " & CType(sender, DropDownList).SelectedItem.Value)

        Catch ex As Exception

            Response.Write(ex.Message)

        End Try

    End Sub