c#树形控件的访问数据库和增删操作

tem.ComponentModel;
using System.Drawing;
using System.Windows.Forms;

namespace UserControls
{
 /// <summary>
 /// TreeViewComboBox 的摘要说明。
 /// </summary>
 public class TreeViewComboBox : UserControl
 {
  /// <summary> 
  /// 必需的设计器变量。
  /// </summary>
  private Container components = null;

  public delegate void EventHandle(TreeNode n);
  public event EventHandle AfterSelectedNode;

  private bool _allowSelectParentNode = false;

  public TreeViewComboBox()
  {
   this.InitializeComponent();

   // Initializing Controls
   this.pnlBack = new Panel();
   this.pnlBack.BorderStyle = BorderStyle.Fixed3D;
   this.pnlBack.BackColor = Color.White;
   this.pnlBack.AutoScroll = false;
   
   this.tbSelectedValue = new TextBox();
   this.tbSelectedValue.BorderStyle = BorderStyle.None;
   this.tbSelectedValue.ReadOnlyChanged += new EventHandler(tbSelectedValue_ReadOnlyChanged);

   this.btnSelect = new ButtonEx();
   this.btnSelect.Click += new EventHandler(ToggleTreeView);
   this.btnSelect.FlatStyle = FlatStyle.Flat;

   this.lblSizingGrip = new LabelEx();
   this.lblSizingGrip.Size = new Size(9,9);
   this.lblSizingGrip.BackColor = Color.Transparent;
   this.lblSizingGrip.Cursor = Cursors.SizeNWSE;
   this.lblSizingGrip.MouseMove += new MouseEventHandler(SizingGripMouseMove);
   this.lblSizingGrip.MouseDown += new MouseEventHandler(SizingGripMouseDown);

   this.tvTreeView = new TreeView();
   this.tvTreeView.BorderStyle = BorderStyle.None;
   this.tvTreeView.DoubleClick += new EventHandler(TreeViewNodeSelect);
   this.tvTreeView.Location = new Point(0,0);
   this.tvTreeView.LostFocus += new EventHandler(TreeViewLostFocus);
   //this.tvTreeView.Scrollable = false;

   this.frmTreeView = new Form();
   this.frmTreeView.FormBorderStyle = FormBorderStyle.None;
   this.frmTreeView.BringToFront();
   this.frmTreeView.StartPosition = FormStartPosition.Manual;
   this.frmTreeView.ShowInTaskbar = false;
   this.frmTreeView.BackColor = SystemColors.Control;

   this.pnlTree = new Panel();
   this.pnlTree.BorderStyle = BorderStyle.FixedSingle;
   this.pnlTree.BackColor = Color.White;
      
   SetStyle(ControlStyles.DoubleBuffer,true);
   SetStyle(ControlStyles.ResizeRedraw,true);

   // Adding Controls to UserControl
   this.pnlTree.Controls.Add(this.lblSizingGrip);
   this.pnlTree.Controls.Add(this.tvTreeView);
   this.frmTreeView.Controls.Add(this.pnlTree);
   this.pnlBack.Controls.AddRange(new Control[]);
   this.Controls.Add(this.pnlBack);
  }

  /// <summary> 
  /// 清理所有正在使用的资源。
  /// </summary>
  protected override void Dispose( bool disposing )
  {
   if( disposing )
   {
    if(components != null)
    {
     components.Dispose();
    }
   }
   base.Dispose( disposing );
  }

  #region 组件设计器生成的代码
  /// <summary> 
  /// 设计器支持所需的方法 - 不要使用代码编辑器 
  /// 修改此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
   // 
   // ComboBoxTree
   // 
   this.Name = "ComboBoxTree";
//   this._absoluteChildrenSelectableOnly = true;
   this.Layout += new LayoutEventHandler(this.ComboBoxTree_Layout);

  }
  #endregion

  #region Private 属性
  private Panel pnlBack;
  private Panel pnlTree;
  private TextBox tbSelectedValue;
  private ButtonEx btnSelect;
  private TreeView tvTreeView;
  private LabelEx lblSizingGrip;
  private Form frmTreeView;

//  private string _branchSeparator;
//  private bool _absoluteChildrenSelectableOnly;
  private Point DragOffset;
  #endregion

  #region Public 属性

  /// <summary>
  /// 是否允许选择非叶子节点
  /// </summary>
  public bool AllowSelectParentNode
  {
   set
   {
    _allowSelectParentNode = value;
   }
   get
   {
    return _allowSelectParentNode;
   }
  }

  public Color TextForeColor
  {
   set 
  }

  public Color TextBackColor
  {
   set 
  }

  /// <summary>
  /// 文本只读属性
  /// </summary>
  public bool TextReadOnly
  {
   set 
  }

  /// <summary>
  /// 树节点集合
  /// </summary>
  public TreeNodeCollection Nodes 
  {
   get 
   {
    return this.tvTreeView.Nodes;
   }
  }

  /// <summary>
  /// 选中的节点
  /// </summary>
  public TreeNode SelectedNode 
  {
   set 
   {
    this.tvTreeView.SelectedNode = value;
   }
   get
   {
    return this.tvTreeView.SelectedNode;
   }
  } 

  /// <summary>
  /// ImageList
  /// </summary>
  public ImageList Imagelist 
  {
   get 
   set 
  }

  /// <summary>
  /// 显示选中的值
  /// </summary>
  public override string Text
  {
   get 
   set 
  }

//  /// <summary>
//  /// 显示完整树节点路径时，路经的分隔符（1位字符）
//  /// </summary>
//  public string BranchSeparator
//  {
//   get 
//   set
//   {
//    if(value.Length > 0)
//     this._branchSeparator = value.Substring(0,1);
//   }
//  }
//
//  /// <summary>
//  /// 是否是叶子节点
//  /// </summary>
//  public bool AbsoluteChildrenSelectableOnly
//  {
//   get 
//   set 
//  }
  #endregion

  /// <summary>
  /// 拖动树背景，改变背景大小
  /// </summary>
  private void RelocateGrip() 
  {
   this.lblSizingGrip.Top = this.frmTreeView.Height - lblSizingGrip.Height - 1;
   this.lblSizingGrip.Left = this.frmTreeView.Width - lblSizingGrip.Width - 1;
  }

  /// <summary>
  /// 点击三角按钮，显示树Form
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void ToggleTreeView(object sender, EventArgs e) 
  {   
   if(!this.frmTreeView.Visible) 
   {
    Rectangle CBRect = this.RectangleToScreen(this.ClientRectangle);
    this.frmTreeView.Location = new Point(CBRect.X, CBRect.Y + this.pnlBack.Height);
    this.tvTreeView.Nodes[0].Expand();
    this.frmTreeView.Show();    
    this.frmTreeView.BringToFront();
   
    this.RelocateGrip();
    //this.tbSelectedValue.Text = "";
   } 
   else 
   {
    this.frmTreeView.Hide();
   }
  }

  /// <summary>
  /// 验证选中的是否是叶子节点
  /// </summary>
  /// <returns></returns>
//  public bool ValidateText()
//  {
//   string ValidatorText = this.Text;
//   TreeNodeCollection TNC = this.tvTreeView.Nodes;
//
//   for(int i = 0; i < ValidatorText.Split(this._branchSeparator.ToCharArray()[0]).Length; i++)
//   {
//    bool NodeFound = false;
//    string NodeToFind = ValidatorText.Split(this._branchSeparator.ToCharArray()[0])[i];
//    for(int j = 0; j < TNC.Count; j++)
//    {
//     if(TNC[j].Text == NodeToFind)
//     {
//      NodeFound = true;
//      TNC = TNC[j].Nodes;
//      break;
//     }
//    }
//
//    if(!NodeFound)
//     return false;
//   }
//
//   return true;
//  }

  #region 事件
  /// <summary>
  /// 改变背景大小，在鼠标移动时发生
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void SizingGripMouseMove(object sender, MouseEventArgs e)
  {
   if(e.Button == MouseButtons.Left)
   {
    int TvWidth, TvHeight;
    TvWidth = Cursor.Position.X - this.frmTreeView.Location.X;
    TvWidth = TvWidth + this.DragOffset.X;
    TvHeight = Cursor.Position.Y - this.frmTreeView.Location.Y;
    TvHeight = TvHeight + this.DragOffset.Y;
    
    if(TvWidth < 50)
     TvWidth = 50;
    if(TvHeight < 50)
     TvHeight = 50;
    
    this.frmTreeView.Size = new Size(TvWidth, TvHeight);
    this.pnlTree.Size = this.frmTreeView.Size;
    this.tvTreeView.Size = new Size(this.frmTreeView.Size.Width - this.lblSizingGrip.Width, this.frmTreeView.Size.Height - this.lblSizingGrip.Width);;
    RelocateGrip();
   }
  }

  /// <summary>
  /// 改变背景大小，在按下鼠标时发生
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void SizingGripMouseDown(object sender, MouseEventArgs e)
  {
   if(e.Button == MouseButtons.Left)
   {
    int OffsetX = Math.Abs(Cursor.Position.X - this.frmTreeView.RectangleToScreen(this.frmTreeView.ClientRectangle).Right);
    int OffsetY = Math.Abs(Cursor.Position.Y - this.frmTreeView.RectangleToScreen(this.frmTreeView.ClientRectangle).Bottom);

    this.DragOffset = new Point(OffsetX, OffsetY);
   }
  }

  /// <summary>
  /// 树型控件失去焦点
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void TreeViewLostFocus(object sender, EventArgs e)
  {
   if(!this.btnSelect.RectangleToScreen(this.btnSelect.ClientRectangle).Contains(Cursor.Position))
    this.frmTreeView.Hide();
  }

  /// <summary>
  /// 选中树型空间节点
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void TreeViewNodeSelect(object sender, EventArgs e) 
  {
   if(this._allowSelectParentNode && this.tvTreeView.SelectedNode != this.tvTreeView.Nodes[0])
   {
    this.tbSelectedValue.Text = this.tvTreeView.SelectedNode.Text;

    this.ToggleTreeView(sender,null);

    AfterSelectedNode(this.tvTreeView.SelectedNode);
   }
   else
   {
    if(this.tvTreeView.SelectedNode.Nodes.Count == 0)
    {
     this.tbSelectedValue.Text = this.tvTreeView.SelectedNode.Text;

     this.ToggleTreeView(sender,null);

     AfterSelectedNode(this.tvTreeView.SelectedNode);
    }
   }
  }

  private void ComboBoxTree_Layout(object sender, LayoutEventArgs e)
  {
   this.Height = this.tbSelectedValue.Height + 8;
   this.pnlBack.Size = new Size(this.Width, this.Height - 2);

   this.btnSelect.Size = new Size(16, this.Height - 6);
   this.btnSelect.Location = new Point(this.Width - this.btnSelect.Width - 4, 0);

   this.tbSelectedValue.Location = new Point(2, 2);
   this.tbSelectedValue.Width = this.Width - this.btnSelect.Width - 4;
   this.frmTreeView.Size = new Size(this.Width + 60, 250);
   this.pnlTree.Size = this.frmTreeView.Size;
   this.tvTreeView.Width = this.frmTreeView.Width - this.lblSizingGrip.Width;
   this.tvTreeView.Height = this.frmTreeView.Height - this.lblSizingGrip.Width;
   this.RelocateGrip();
  }

  /// <summary>
  /// 文本只读事件
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void tbSelectedValue_ReadOnlyChanged(object sender, EventArgs e)
  {
   if(this.tbSelectedValue.ReadOnly)
   {
    this.tbSelectedValue.BackColor = Color.White;
   }
  }
  #endregion

  #region 树型背景Label
  private class LabelEx : Label 
  {
   /// <summary>
   /// 
   /// </summary>
   public LabelEx() 
   {
    this.SetStyle(ControlStyles.UserPaint,true);
    this.SetStyle(ControlStyles.DoubleBuffer,true);
    this.SetStyle(ControlStyles.AllPaintingInWmPaint,true);
   }

   /// <summary>
   /// 
   /// </summary>
   /// <param name="e"></param>
   protected override void OnPaint(PaintEventArgs e) 
   {
    base.OnPaint(e);
    ControlPaint.DrawSizeGrip(e.Graphics,Color.Black, 1, 0, this.Size.Width, this.Size.Height);
   }
  }
  #endregion
 
  #region 三角形按钮
  private class ButtonEx : Button 
  {
   ButtonState state;

   /// <summary>
   /// 
   /// </summary>
   public ButtonEx() 
   {
    this.SetStyle(ControlStyles.UserPaint,true);
    this.SetStyle(ControlStyles.DoubleBuffer,true);
    this.SetStyle(ControlStyles.AllPaintingInWmPaint,true);

   }
   /// <summary>
   /// 
   /// </summary>
   /// <param name="e"></param>
   protected override void OnMouseDown(MouseEventArgs e) 
   {
    state = ButtonState.Pushed;
    base.OnMouseDown(e);
   }

   /// <summary>
   /// 
   /// </summary>
   /// <param name="e"></param>
   protected override void OnMouseUp(MouseEventArgs e) 
   {
    state = ButtonState.Normal;
    base.OnMouseUp(e);
   }

   /// <summary>
   /// 
   /// </summary>
   /// <param name="e"></param>
   protected override void OnPaint(PaintEventArgs e) 
   {
    base.OnPaint(e);
    ControlPaint.DrawComboButton(e.Graphics, 0, 0, this.Width, this.Height, state);
   }
  }
  #endregion

 }

}