It has the value but don't know why still throwing nullRefrenceException.
This is my code for treeView with ChildView.
I want to make a treeView with parent and child from DataSet.
Code:
adp3 = new SqlDataAdapter("select country.CountryId , country.CountryName ,` city.CityId , city.CityName "+
" from Country as country join City as city on city.CountryId = country.CountryId order by cityid ", Program.con);
adp3.Fill(ds,"bb");
this.mtree.Nodes.Clear();
string mdt = "";
string mref = "";
string mtitle = "";
foreach (DataRow row in ds.Tables["bb"].Rows)
{
if (!row["Countryname"].ToString().Equals(mdt.Trim()))
{
TreeNode node = new TreeNode();
node.Name = (string)row["CountryId"].ToString().Trim();
node.Text = row["CountryName"].ToString();
this.mtree.Nodes.Add(node);
mdt = row["CountryName"].ToString().Trim();
mtitle = "";
}
else if (!row["CityName"].ToString().Equals(mtitle.Trim()))
{
TreeNode node2 = new TreeNode();
node2.Name = (string)row["CityId"].ToString().Trim();
node2.Text = row["CityName"].ToString().Trim();
this.mtree.Nodes[mdt.Trim()].Nodes.Add(node2);
mtitle = row["CityName"].ToString().Trim();
}
}