Check whether ASP.Net GridView row is selected or not using C# and VB.Net

Hi dorsa,

Put an hiddenfield to verify user has selected any row or not.

Check this example. Now please take its reference and correct your code.

HTML

<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" DataKeyNames="Id"
    DataSourceID="EditCourseDB">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" ReadOnly="True" Visible="false"></asp:BoundField>
        <asp:BoundField DataField="Title" HeaderText="Title"></asp:BoundField>
        <asp:BoundField DataField="Floor" HeaderText="Floor"></asp:BoundField>
        <asp:BoundField DataField="Capacity" HeaderText="Capacity"></asp:BoundField>
        <asp:BoundField DataField="TypeId" HeaderText="TypeId"></asp:BoundField>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:Button ID="Button1" Text="Get Value" runat="server" OnClick="GridView_Button_Click" />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<asp:HiddenField ID="hfSelected" runat="server" />
<asp:SqlDataSource ID="EditCourseDB" runat="server" ConnectionString="<%$ ConnectionStrings:KDUIS-v1ConnectionString %>"
    SelectCommand="SELECT * FROM [EDU_Room]"></asp:SqlDataSource>
<br />
<asp:Button Text="Save" runat="server" OnClick="Save" />

C#

protected void GridView_Button_Click(object sender, EventArgs e)
{
    GridViewRow row = (GridViewRow)(sender as Button).NamingContainer;
    hfSelected.Value = GridView2.DataKeys[row.RowIndex].Values[0].ToString();
    foreach (GridViewRow row1 in GridView2.Rows)
    {
        if (row1.RowIndex == row.RowIndex)
        {
            row1.BackColor = System.Drawing.ColorTranslator.FromHtml("#A1DCF2");
        }
        else
        {
            row1.BackColor = System.Drawing.ColorTranslator.FromHtml("#FFFFFF");
        }
    }
}

protected void Save(object sender, EventArgs e)
{
    if (string.IsNullOrEmpty(hfSelected.Value))
    {
        ScriptManager.RegisterStartupScript(this, this.GetType(), "alert", "alert('Please select any Row');", true);
    }
    else
    {
        // Do your task.
        ScriptManager.RegisterStartupScript(this, this.GetType(), "alert", "alert('Selected id is : " + hfSelected.Value + "');", true);
    }
}

VB.Net

Protected Sub GridView_Button_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim row As GridViewRow = CType((TryCast(sender, Button)).NamingContainer, GridViewRow)
    hfSelected.Value = GridView2.DataKeys(row.RowIndex).Values(0).ToString()
    For Each row1 As GridViewRow In GridView2.Rows
        If row1.RowIndex = row.RowIndex Then
            row1.BackColor = System.Drawing.ColorTranslator.FromHtml("#A1DCF2")
        Else
            row1.BackColor = System.Drawing.ColorTranslator.FromHtml("#FFFFFF")
        End If
    Next
End Sub

Protected Sub Save(ByVal sender As Object, ByVal e As EventArgs)
    If String.IsNullOrEmpty(hfSelected.Value) Then
        ScriptManager.RegisterStartupScript(Me, Me.GetType(), "alert", "alert('Please select any Row');", True)
    Else
        ' Do your task.
        ScriptManager.RegisterStartupScript(Me, Me.GetType(), "alert", "alert('Selected id is : " & hfSelected.Value & "');", True)
    End If
End Sub

Screenshot