ViewState in GridView ASP.Net

Question

I have a gridview that is connected to a datasource in the aspx code. The selected gridview row is hidden on clcik on button. I want to hide the row permenantly, even if user logs off and logs in the hidden row should not be shown. I have tried using ViewState but it doesnt work. Anyone have any idea on how to accomplish this.

My gridview:

edit Select Approve data1 data2 data3

when the user clicks select and the approve button the row is hidden. I want all rows to be called except the one that is clicked, the clicked row should not be displayed at all. I did some research and found out the ViewState is the best but do not know how to accomplish it.

My Behind Code:

SqlConnection con = new SqlConnection("Data Source=User-PC\\User;Initial Catalog=Subject Registration System;Integrated Security=True");

protected void Page_Load(object sender, EventArgs e)

{

if (Session["username"] != null)

{

Label1.Text = Session["username"].ToString();

}

con.Open();

SqlCommand cmd = new SqlCommand("SELECT FullName FROM [Programme Leader] WHERE Username= '" + Label1.Text + "'", con);

SqlDataReader reader = cmd.ExecuteReader();

reader.Read();

Label1.Text = reader["FullName"].ToString();

reader.Close();

con.Close();

if (!Page.IsPostBack)

{

string gd;

gd = (string)ViewState["Gridview"];

}

Panel2.Visible=true;

Panel3.Visible = false;

}

protected void DDL1_SelectedIndexChanged(object sender, EventArgs e)

{

Panel2.Visible = true;

}

protected void GridView2_RowEditing(object sender, GridViewEditEventArgs e)

{

Panel2.Visible = true;

GridView2.DataBind();

}

protected void GridView2_RowUpdated(object sender, GridViewUpdatedEventArgs e)

{

Panel2.Visible = true;

GridView2.DataBind();

}

protected void Button1_Click(object sender, EventArgs e)

{

GridView1.SelectedRow.Visible = false;

ViewState["gridview"]=GridView1;

}

protected void Button2_Click(object sender, EventArgs e)

{

Response.Redirect("~/Programme Leader Front Page.aspx");

}

}

}

 

Thank you