How to populate a treeview from a dataset

Question

Hi!

I am very new to C#. I need to create a Windows form that will read a SQL table and populate a treeview. I can connect to the <acronym style="border-style:initial;border-color:initial;cursor:help;">DB</acronym>, create the dataadapter, populate a data set. The problem is how to use the dataset to populate a treeview.  

I have looked at a few examples but none use a dataset, or the data structure was different and I could not modify to work with my data or the examples were more than I needed and too complex for a beginner.

I have a sql server containing the fields:   ID, Date, Name

01-Mar-2012

          |----A

          |----B

          |----C

02-Mar-2012

          |----D

          |----E

          |----F

I want to populate the data like above.

I would really appreciate the help.

Thank you.

---

Apurba Doley

Answer 1

Hi Apurba,
Iterate through the DataTable and add Node to the TreeView, see 

DataSet ds = new DataSet();
DataTable dt = new DataTable();
private void Form1_Load(object sender, EventArgs e)
{
    dt.TableName = "YourTableName";
    dt.Columns.Add("ID");
    dt.Columns.Add("Date",typeof(DateTime));
    dt.Columns.Add("Name");

    dt.Rows.Add("1", DateTime.Parse("01-Mar-2012"),"A");
    dt.Rows.Add("2", DateTime.Parse("01-Mar-2012"), "B");
    dt.Rows.Add("3", DateTime.Parse("01-Mar-2012"), "C");
    dt.Rows.Add("4", DateTime.Parse("02-Mar-2012"), "D");
    dt.Rows.Add("5", DateTime.Parse("02-Mar-2012"), "E");
    dt.Rows.Add("6", DateTime.Parse("02-Mar-2012"), "F");
    ds.Tables.Add(dt);

    foreach (DataRow dr in ds.Tables["YourTableName"].Rows)
    {
        TreeNode tn;
        TreeNode tn2 = new TreeNode(dr["Name"].ToString());
        string drDate = ((DateTime)dr["Date"]).ToString("dd-MMM-yyyy");
        if (treeView1.Nodes.IndexOfKey(drDate) == -1)
        {
            tn = new TreeNode(drDate);
            tn.Name = drDate;
            tn.Nodes.Add(tn2);
            treeView1.Nodes.Add(tn);
        }
        else
        {
            tn = treeView1.Nodes[treeView1.Nodes.IndexOfKey(drDate)];
            tn.Nodes.Add(tn2);
        }
    }
}

If you still have any doubt about this issue, please let me know.
Best Regards,

---

Bob Wu [MSFT]
MSDN Community Support | Feedback to us

Answer 2

Hi Bob! Thanks for your code. It helped me a lot. I need to populate dynamically from the database. For you kind information i have one table consisting fields: ID, Date, Name.

Example:

ID Date         Name
1       01/03/2012      A
2       01/03/2012      B
3       01/03/2012      C
4       01/03/2012      D
5       02/03/2012      E
6       02/03/2012      F
7       02/03/2012      G
8       02/03/2012      H

So i need to display all names for a particular date accordingly. How do i do please suggest. Thank you.

---

Apurba Doley

Answer 3

It’s similar just compare the particular date and the data in current row.

treeView1.Nodes.Clear();
string particularDate = "02-Mar-2012";
foreach (DataRow dr in ds.Tables["YourTableName"].Rows)
{
    TreeNode tn;
    TreeNode tn2 = new TreeNode(dr["Name"].ToString());
    //string drDate = ((DateTime)dr["Date"]).ToString("dd-MMM-yyyy");
    string drDate = particularDate;
    if(!string.Equals(drDate,((DateTime)dr["Date"]).ToString("dd-MMM-yyyy"),StringComparison.OrdinalIgnoreCase))
    {
        continue;
    }
    if (treeView1.Nodes.IndexOfKey(drDate) == -1)
    {
        tn = new TreeNode(drDate);
        tn.Name = drDate;
        tn.Nodes.Add(tn2);
        treeView1.Nodes.Add(tn);
    }
    else
    {
        tn = treeView1.Nodes[treeView1.Nodes.IndexOfKey(drDate)];
        tn.Nodes.Add(tn2);
    }
}

Best Regards,

---

Bob Wu [MSFT]
MSDN Community Support | Feedback to us