pathnavigator.cs

this is a good book for the visual c#

      this.Text = "PathNavigator";
      this.navigateBox.ResumeLayout(false);
      this.locateBox.ResumeLayout(false);
      this.ResumeLayout(false);

   }
      #endregion

   [STAThread]
   static void Main() 
   {
      Application.Run( new PathNavigator() );
   }

   // traverse to first child
   private void firstChildButton_Click( object sender, 
      System.EventArgs e )
   {
      TreeNode newTreeNode;

      // move to first child
      if ( xpath.MoveToFirstChild() )
      {
         newTreeNode = new TreeNode(); // create new node
         
         // set node's Text property to either 
         // navigator's name or value
         DetermineType( newTreeNode, xpath );

         // add node to TreeNode node list
         tree.Nodes.Add( newTreeNode ); 
         tree = newTreeNode; // assign tree newTreeNode
            
         // update TreeView control
         pathTreeViewer.ExpandAll();
         pathTreeViewer.Refresh();
         pathTreeViewer.SelectedNode = tree;
      }
      else // node has no children
         MessageBox.Show( "Current Node has no children.", 
            "", MessageBoxButtons.OK,
            MessageBoxIcon.Information );
   }

   // traverse to node's parent on parentButton click event
   private void parentButton_Click( object sender, 
      System.EventArgs e )
   {
      // move to parent
      if ( xpath.MoveToParent() ) 
      {
         tree = tree.Parent;

         // get number of child nodes, not including sub trees
         int count = tree.GetNodeCount( false );
         
         // remove all children
         tree.Nodes.Clear();

         // update TreeView control
         pathTreeViewer.ExpandAll();
         pathTreeViewer.Refresh();
         pathTreeViewer.SelectedNode = tree;
      }
      else // if node has no parent (root node)
         MessageBox.Show( "Current node has no parent.", "",
            MessageBoxButtons.OK,
            MessageBoxIcon.Information );
   }

   // find next sibling on nextButton click event
   private void nextButton_Click( object sender, 
      System.EventArgs e )
   {
      TreeNode newTreeNode = null, newNode = null;

      // move to next sibling
      if ( xpath.MoveToNext() ) 
      {
         newTreeNode = tree.Parent; // get parent node
         
         newNode = new TreeNode(); // create new node
         DetermineType( newNode, xpath );
         newTreeNode.Nodes.Add( newNode );

         // set current position for display
         tree = newNode;

         // update TreeView control
         pathTreeViewer.ExpandAll();
         pathTreeViewer.Refresh();
         pathTreeViewer.SelectedNode = tree;
      }
      else // node has no additional siblings
         MessageBox.Show( "Current node is last sibling.", 
            "", MessageBoxButtons.OK,
            MessageBoxIcon.Information );
   } // end nextButton_Click

   // get previous sibling on previousButton click
   private void previousButton_Click( object sender, 
      System.EventArgs e )
   {
      TreeNode parentTreeNode = null;

      // move to previous sibling
      if ( xpath.MoveToPrevious() )
      {
         parentTreeNode = tree.Parent; // get parent node
            
         // delete current node           
         parentTreeNode.Nodes.Remove( tree );
           
         // move to previous node
         tree = parentTreeNode.LastNode;
            
         // update TreeView control
         pathTreeViewer.ExpandAll();
         pathTreeViewer.Refresh();
         pathTreeViewer.SelectedNode = tree;
      }
      else // if current node has no previous siblings
         MessageBox.Show( "Current node is first sibling.",
            "", MessageBoxButtons.OK,
            MessageBoxIcon.Information );
   } // end previousButton_Click

   // process selectButton click event
   private void selectButton_Click( object sender, 
      System.EventArgs e )
   {
      XPathNodeIterator iterator; // enables node iteration

      // get specified node from ComboBox
      try
      {
         iterator = xpath.Select( selectComboBox.Text );
         DisplayIterator( iterator ); // print selection
      }

         // catch invalid expressions
      catch ( System.ArgumentException argumentException ) 
      {
         MessageBox.Show( argumentException.Message, 
            "Error", MessageBoxButtons.OK,
            MessageBoxIcon.Error );
      }
   } // end selectButton_Click

   // print values for XPathNodeIterator
   private void DisplayIterator( XPathNodeIterator iterator ) 
   {
      selectTreeViewer.Text = "";

      // prints selected node's values
      while ( iterator.MoveNext() )
         selectTreeViewer.Text += 
            iterator.Current.Value.Trim()
            + "\r\n";
   } // end DisplayIterator
      
   // determine if TreeNode should display current node 
   // name or value
   private void DetermineType( TreeNode node, 
      XPathNavigator xPath ) 
   {
      // determine NodeType
      switch ( xPath.NodeType ) 
      {
            // if Element, get its name
         case XPathNodeType.Element: 

            // get current node name, and remove whitespace
            node.Text = xPath.Name.Trim();
            break;
      
            // obtain node values
         default: 

            // get current node value and remove whitespace
            node.Text = xPath.Value.Trim();
            break;

      } // end switch
   } // end DetermineType
} // end PathNavigator


/*
 **************************************************************************
 * (C) Copyright 2002 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors and publisher of this book have used their     *
 * best efforts in preparing the book. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these books. The authors *
 * and publisher shall not be liable in any event for incidental or       *
 * consequential damages in connection with, or arising out of, the       *
 * furnishing, performance, or use of these programs.                     *
 **************************************************************************
*/