Populate a TreeView from a SELF-JOINED table

• Download source code - 10.4 Kb

Introduction

This very simple example provides a demonstration of how one can populate a TreeView from a self-joined database table. In this example I have used a DataSet containing one DataTable that is populated with virtual XML data.

Core

The SimpleDataSet class provides a DataTable populated with self-joined data. The SimpleTreeView the actual data consumer object.

Sample of how the TreeView is populated

public void CreateNodesOfParent(int iParent,TreeNode pNode) {
            
    DataView dvwData = new DataView(sdsData.Tables[0]);

    dvwData.RowFilter =  "[PARENT] = " + iParent;
    
    foreach(DataRowView Row in dvwData) {
                

        // Call Stack !
        if(pNode == null) {
            TreeNode zNode = this.Nodes.Add(Row["Caption"].ToString());
            CreateNodesOfParent(Int32.Parse(Row["ID"].ToString()),zNode);
        } else {
            TreeNode zNode =  pNode.Nodes.Add(Row["Caption"].ToString());
            CreateNodesOfParent(Int32.Parse(Row["ID"].ToString()),zNode);    
        }
                        
    }            
}        

Sample of how the DataTable is populated

private void CreateDummyData() {
            
    //DataRow objRow;
    // Creating columns
    prvTable = new DataTable("tblTreeView");
    prvTable.Columns.Add("ID",typeof(Int32));
    prvTable.Columns.Add("PARENT",typeof(Int32));
    prvTable.Columns.Add("CAPTION",typeof(String));
            
    // Adding Table to DataSet
    this.Tables.Add(prvTable);
            
                
    prvTable.Rows.Add(new Object[] {1,0,"Countries"});
        prvTable.Rows.Add(new Object[] {2,1,"Netherlands"});
            prvTable.Rows.Add(new Object[] {3,2,"Cities"});            
            prvTable.Rows.Add(new Object[] {4,3,"The Hague"});
            prvTable.Rows.Add(new Object[] {5,3,"Amsterdam"});
            prvTable.Rows.Add(new Object[] {6,3,"Rotterdam"});
    ......
    ......            
}

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here