TreeView.BeforeExpand
/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace TreeViewDataBinding
{
/// <summary>
/// Summary description for TreeViewDataBinding.
/// </summary>
public class TreeViewDataBinding : System.Windows.Forms.Form
{
internal System.Windows.Forms.Panel Panel2;
internal System.Windows.Forms.Panel Panel3;
internal System.Windows.Forms.Label lblInfo;
internal System.Windows.Forms.Label Label1;
internal System.Windows.Forms.Splitter Splitter1;
internal System.Windows.Forms.TreeView treeDB;
internal System.Windows.Forms.Panel Panel1;
internal System.Windows.Forms.Button cmdClose;
internal System.Windows.Forms.GroupBox GroupBox1;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public TreeViewDataBinding()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Panel2 = new System.Windows.Forms.Panel();
this.Panel3 = new System.Windows.Forms.Panel();
this.lblInfo = new System.Windows.Forms.Label();
this.Label1 = new System.Windows.Forms.Label();
this.Splitter1 = new System.Windows.Forms.Splitter();
this.treeDB = new System.Windows.Forms.TreeView();
this.Panel1 = new System.Windows.Forms.Panel();
this.cmdClose = new System.Windows.Forms.Button();
this.GroupBox1 = new System.Windows.Forms.GroupBox();
this.Panel2.SuspendLayout();
this.Panel3.SuspendLayout();
this.Panel1.SuspendLayout();
this.SuspendLayout();
//
// Panel2
//
this.Panel2.Controls.AddRange(new System.Windows.Forms.Control[] {
this.Panel3,
this.Splitter1,
this.treeDB});
this.Panel2.Dock = System.Windows.Forms.DockStyle.Fill;
this.Panel2.Location = new System.Drawing.Point(5, 5);
this.Panel2.Name = "Panel2";
this.Panel2.Size = new System.Drawing.Size(446, 264);
this.Panel2.TabIndex = 8;
//
// Panel3
//
this.Panel3.Controls.AddRange(new System.Windows.Forms.Control[] {
this.lblInfo,
this.Label1});
this.Panel3.Dock = System.Windows.Forms.DockStyle.Fill;
this.Panel3.Location = new System.Drawing.Point(239, 0);
this.Panel3.Name = "Panel3";
this.Panel3.Size = new System.Drawing.Size(207, 264);
this.Panel3.TabIndex = 7;
//
// lblInfo
//
this.lblInfo.Anchor = (((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.lblInfo.BackColor = System.Drawing.SystemColors.Window;
this.lblInfo.Location = new System.Drawing.Point(16, 12);
this.lblInfo.Name = "lblInfo";
this.lblInfo.Size = new System.Drawing.Size(176, 240);
this.lblInfo.TabIndex = 1;
//
// Label1
//
this.Label1.Anchor = (((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.Label1.BackColor = System.Drawing.SystemColors.Window;
this.Label1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
this.Label1.Location = new System.Drawing.Point(4, 0);
this.Label1.Name = "Label1";
this.Label1.Size = new System.Drawing.Size(200, 264);
this.Label1.TabIndex = 2;
//
// Splitter1
//
this.Splitter1.Location = new System.Drawing.Point(236, 0);
this.Splitter1.Name = "Splitter1";
this.Splitter1.Size = new System.Drawing.Size(3, 264);
this.Splitter1.TabIndex = 6;
this.Splitter1.TabStop = false;
//
// treeDB
//
this.treeDB.Dock = System.Windows.Forms.DockStyle.Left;
this.treeDB.ImageIndex = -1;
this.treeDB.Name = "treeDB";
this.treeDB.SelectedImageIndex = -1;
this.treeDB.Size = new System.Drawing.Size(236, 264);
this.treeDB.TabIndex = 4;
this.treeDB.AfterSelect += new System.Windows.Forms.TreeViewEventHandler(this.treeDB_AfterSelect);
this.treeDB.BeforeExpand += new System.Windows.Forms.TreeViewCancelEventHandler(this.treeDB_BeforeExpand);
//
// Panel1
//
this.Panel1.Controls.AddRange(new System.Windows.Forms.Control[] {
this.cmdClose,
this.GroupBox1});
this.Panel1.Dock = System.Windows.Forms.DockStyle.Bottom;
this.Panel1.Location = new System.Drawing.Point(5, 269);
this.Panel1.Name = "Panel1";
this.Panel1.Size = new System.Drawing.Size(446, 36);
this.Panel1.TabIndex = 7;
//
// cmdClose
//
this.cmdClose.Anchor = (System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right);
this.cmdClose.FlatStyle = System.Windows.Forms.FlatStyle.System;
this.cmdClose.Location = new System.Drawing.Point(372, 12);
this.cmdClose.Name = "cmdClose";
this.cmdClose.Size = new System.Drawing.Size(72, 24);
this.cmdClose.TabIndex = 4;
this.cmdClose.Text = "Close";
this.cmdClose.Click += new System.EventHandler(this.cmdClose_Click);
//
// GroupBox1
//
this.GroupBox1.Anchor = ((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.GroupBox1.Name = "GroupBox1";
this.GroupBox1.Size = new System.Drawing.Size(444, 8);
this.GroupBox1.TabIndex = 5;
this.GroupBox1.TabStop = false;
//
// TreeViewDataBinding
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
this.ClientSize = new System.Drawing.Size(456, 310);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.Panel2,
this.Panel1});
this.DockPadding.All = 5;
this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
this.Name = "TreeViewDataBinding";
this.Text = "TreeViewDataBinding";
this.Load += new System.EventHandler(this.TreeViewDataBinding_Load);
this.Panel2.ResumeLayout(false);
this.Panel3.ResumeLayout(false);
this.Panel1.ResumeLayout(false);
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new TreeViewDataBinding());
}
private ProductDatabase DataClass = new ProductDatabase();
private void TreeViewDataBinding_Load(object sender, System.EventArgs e)
{
TreeNode nodeParent;
foreach (DataRow row in DataClass.GetCategories().Rows)
{
// Add the category node.
nodeParent = treeDB.Nodes.Add(row[ProductDatabase.CategoryField.Name].ToString());
nodeParent.ImageIndex = 0;
// Store the disconnected category information.
nodeParent.Tag = row;
// Add a "dummy" node.
nodeParent.Nodes.Add("*");
}
}
private void treeDB_BeforeExpand(object sender, System.Windows.Forms.TreeViewCancelEventArgs e)
{
TreeNode nodeSelected, nodeChild;
nodeSelected = e.Node;
if (nodeSelected.Nodes[0].Text == "*")
{
// This is a dummy node.
nodeSelected.Nodes.Clear();
foreach (DataRow row in
DataClass.GetProductsInCategory((DataRow)nodeSelected.Tag))
{
nodeChild = nodeSelected.Nodes.Add(row[ProductDatabase.ProductField.Name].ToString());
// Store the disconnected product information.
nodeChild.Tag = row;
nodeChild.ImageIndex = 1;
nodeChild.SelectedImageIndex = 1;
}
}
}
private void treeDB_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
{
lblInfo.Text = DataClass.GetDisplayText((DataRow)e.Node.Tag);
}
private void cmdClose_Click(object sender, System.EventArgs e)
{
this.Close();
}
}
public class ProductDatabase
{
public class Tables
{
public const string Product = "Products";
public const string Category = "Categories";
}
public class ProductField
{
public const string Name = "ModelName";
public const string Description = "Description";
}
public class CategoryField
{
public const string Name = "CategoryName";
}
private DataSet dsStore;
DataRelation relCategoryProduct;
public ProductDatabase()
{
dsStore = new DataSet();
dsStore.ReadXmlSchema(Application.StartupPath + "\\store.xsd");
dsStore.ReadXml(Application.StartupPath + "\\store.xml");
// Define the relation.
relCategoryProduct = new DataRelation("Prod_Cat",
dsStore.Tables["Categories"].Columns["CategoryID"],
dsStore.Tables["Products"].Columns["CategoryID"]);
dsStore.Relations.Add(relCategoryProduct);
}
public DataTable GetCategories()
{
return dsStore.Tables["Categories"];
}
public DataRow[] GetProductsInCategory(DataRow rowParent)
{
return rowParent.GetChildRows(relCategoryProduct);
}
public string GetDisplayText(DataRow row)
{
string text = "";
switch (row.Table.TableName)
{
case Tables.Product:
text = "ID: " + row[0] + "\n";
text += "Name: " + row[ProductField.Name] + "\n\n";
text += row[ProductField.Description];
break;
}
return text;
}
}
}
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