How to add Like/Unlike functionality in GridView?

Question

If I enter the values manually in database for like then I can view it on the wall but I do not know how to insert value programatically on clicking 'like'. The query which i would like to get fired on clicking 'like' (which is in every row below msg) is "insert into tbl_like (ScrapId,FromId,LikeStatus) values(A*,sessionUserID,1)";

A* = this must be the Scrapid of that particular row in which like was clicked.

Database Table: Scrap_Table: ScrapId | FromId | ToId | msg

Like_table:

LikeId | ScrapId | FromId | LikeStatus

Source Code:

   <asp:GridView ID="GridViewUserScraps" ItemStyle-VerticalAlign="Top" AutoGenerateColumns="False"
                GridLines="None" Width="100%" ShowHeader="False" runat="server" AlternatingRowStyle-BackColor="#A5A5A5"
                CellPadding="4" ForeColor="#333333" DataKeyNames="ScrapId" 
                OnItemCommand="CommandLinkClicked">
                <Columns>
                    <asp:TemplateField>
                        <ItemTemplate>
                            <table align="left" cellpadding="1" cellspacing="2">
                                <tr>
                                    <td>
                                        <a href='<%#getUserHREF(Container.DataItem)%>'>
                                            <img align="middle" src='<%#getSRC(Container.DataItem)%>' border="0" width="50px" /></a>
                                    </td>
                                    <td>
                                        &nbsp;</td>
                                </tr>
                            </table>
                            <div align="justify">
                                <%#DataBinder.Eval(Container.DataItem, "Message")%>
                                <br />
                                <br />
                            </div>
                            <span class="SmallBlackText">Posted On: &nbsp;</span>
                            <asp:Label ID="lblSendDate" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"SendDate")%>'></asp:Label>
                            </span>
                            <br />
                           <%-- <asp:LinkButton ID="lnklike" runat="server" 
                                CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" 
                                CommandName="LikeCmd">Like</asp:LinkButton>
                            &nbsp;&nbsp;&nbsp;
                            <asp:LinkButton ID="lnkunlike" runat="server">unlike</asp:LinkButton>--%>

                            <asp:LinkButton ID="lnklike" runat="server" CommandName="like" CommandArgument='<%# Eval("ScrapId")%>'>Like</asp:LinkButton>
    <asp:LinkButton ID="lnkunlike" runat="server"  CommandName="unlike" CommandArgument='<%# Eval("ScrapId")%>'>unlike</asp:LinkButton>



                            &nbsp;&nbsp;
                            <asp:Label ID="lbllike" runat="server" Text="likes:"></asp:Label>
                           <%-- <asp:Label ID="lbllikecount" runat="server" Text="0"></asp:Label>--%>


                        <asp:Label ID="Label1" runat="server" Text='<%# Controls_GetUserScraps.abc((int)Eval("ScrapId")) %>' />
                          <%--<asp:Label ID="Label1" runat="server" Text='<%# WebPageName.StaticMethodName((int)Eval("ScrapId")) %>' />--%>

                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
                <RowStyle BackColor="#EFF3FB" />
                <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
                <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
                <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                <EditRowStyle BackColor="#2461BF" />
                <AlternatingRowStyle BackColor="White" />
            </asp:GridView>

Code Behind:

DataBaseClass dbClass = new DataBaseClass();
public DataTable dt;

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {

        GetUserScraps(int.Parse(Request.QueryString["Id"].ToString()));
    }
}
public void GetUserScraps(int Id)
{

    string getUserScraps = "SELECT u.Id as UserId,u.firstname,u.ImageName,s.FromId,s.ToId,s.Message,s.SendDate,s.ID as ScrapId FROM [User] as u, Scrap as s WHERE u.Id=s.FromId AND s.ToId='" + Request.QueryString["Id"].ToString() + "'";
  //string getlikes = "select COUNT(*) from tbl_like inner join Scrap on tbl_like.scrapid=Scrap.Id where tbl_like.likestatus=1 and tbl_like.scrapid='"+<%#DataBinder.Eval(Container.DataItem,"ScrapId")%>+"'";
  //  <%#DataBinder.Eval(Container.DataItem,"ScrapId")%>


    dt = dbClass.ConnectDataBaseReturnDT(getUserScraps);
    if (dt.Rows.Count > 0)
    {
        GridViewUserScraps.DataSource = dt;
        GridViewUserScraps.DataBind();
    }
}

public string getUserHREF(object sURL)
{
    DataRowView dRView = (DataRowView)sURL;
    string Id = dRView["UserId"].ToString();
    return ResolveUrl("~/UserDetails.aspx?Id=" + Id);
}

public string getSRC(object imgSRC)
{
    DataRowView dRView = (DataRowView)imgSRC;
    string ImageName = dRView["ImageName"].ToString();
    if (ImageName == "NoImage")
    {
        return ResolveUrl(@"~/Site_Images/image_missing.jpg");
    }
    else
    {
        return ResolveUrl("~/UserImage/" + dRView["ImageName"].ToString());
    }
}

public static int abc(int scrpid)
{

    string getlikes = "select COUNT(*) from tbl_like inner join Scrap on tbl_like.scrapid=Scrap.Id where tbl_like.likestatus=1 and tbl_like.scrapid='"+scrpid+"'";

    dboperation dbo = new dboperation();
    int a = dbo.GetLikesMethod(getlikes);

    return a;
}


protected void CommandLinkClicked(object sender, DataGridCommandEventArgs e)
{
    var scrapId = Int32.Parse(e.CommandArgument.ToString());
    switch (e.CommandName)
    {
        case "like":
            var con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["constr"].ConnectionString); //your connection string
            var cmd = new SqlCommand("insert into tbl_like (ScrapId,FromId,LikeStatus) values(@scrapId,@sessionUser,1)");
            cmd.Parameters.AddWithValue("@scrapId", scrapId);
            cmd.Parameters.AddWithValue("@sessionUser", Session["UserId"]);
            cmd.Connection = con;
            con.Open();
            cmd.ExecuteNonQuery();
            break;
        case "unlike":
            //do stuff
            break;
    }
}

}

Answer 1

You have to add OnItemCommand event to your grid to handle clicks on link buttons. Also both of link buttons must have CommandName and CommandArgument set.

Change yours html as follows:

<asp:GridView .... OnRowCommand="GridViewRowCommand">

    <asp:LinkButton ID="lnklike" runat="server" CommandName="like" CommandArgument='<%# Eval("ScrapId")%>'>Like</asp:LinkButton>
    <asp:LinkButton ID="lnkunlike" runat="server"  CommandName="unlike" CommandArgument='<%# Eval("ScrapId")%>'>unlike</asp:LinkButton>

</asp:GridView>

And this is event in code behind:

protected void GridViewRowCommand(Object sender, GridViewCommandEventArgs e)
{
    var scrapId = Int32.Parse(e.CommandArgument.ToString());
    switch (e.CommandName)
    {
        case "like" : 
                using (var con = new SqlConnection("connection_string")) //your connection string
                {
                   var cmd = new SqlCommand("insert into tbl_like (ScrapId,FromId,LikeStatus) values(@scrapId,@sessionUser,1)");
                   cmd.Parameters.AddWithValue("@scrapId", scrapId);
                   cmd.Parameters.AddWithValue("@sessionUser", Session[User]); 
                   cmd.Connection = con;
                   con.Open();
                   cmd.ExecuteNonQuery();
                }
                break;
        case "unlike" : 
                //do stuff
                break;
    }
}