update data in gridview control

Question

hello friends... 

 

this is my code

 

protected void update(object sender, GridViewUpdateEventArgs e)

{

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["dbconnectionstr"].ConnectionString);

int id = int.Parse(GridView1.DataKeys[e.RowIndex].Value.ToString());

string qry = "update City_tbl set State=@State,City=@City where id=" + id + "";

SqlCommand cmd = new SqlCommand(qry, con);

cmd.Parameters.AddWithValue("@State", SqlDbType.NVarChar).Value = state.Text.Trim();

cmd.Parameters.AddWithValue("@City", SqlDbType.NVarChar).Value = TextBox1.Text.Trim();

// cmd.Parameters.AddWithValue("@State", ((DropDownList)GridView1.Rows[e.RowIndex].Cells[3].Controls[0]).SelectedItem.Value.ToString());

//cmd.Parameters.AddWithValue("@City", ((TextBox)GridView1.Rows[e.RowIndex].Cells[4].Controls[0]).Text.ToString());

con.Open();

cmd.ExecuteNonQuery();

con.Close();

GridView1.EditIndex = -1;

BindData();

}

 

here state is dropdown control and city is textbox control.. when click update button then value got null value .. plase someone help me.. thankyou