Try this:
public List<Model.Skill> GetSkillsOfProject(int ProjectId)
{
List<Model.Skill> skllist = new List<Model.Skill>();
con.Open();
SqlDataAdapter sda = new SqlDataAdapter("GetSkillsOfProject", con);
sda.SelectCommand.CommandType = CommandType.StoredProcedure;
sda.SelectCommand.Parameters.AddWithValue("@ProjectId", ProjectId);
sda.Fill(dt);
for (int i = 0; i < dt.Rows.Count; i++)
{
Model.Skill skl = new Model.Skill();
skl.Name = dt.Rows[i]["Name"].ToString();
skllist.Add(skl);
}
return skllist;
}