using System;

 using System.Collections.Generic;

 using System.ComponentModel;

 using System.Drawing;

 using System.Data;

 using System.Linq;

 using System.Text;

 using System.Windows.Forms;

 using System.Collections;

 using System.Reflection;

 using Newtonsoft.Json.Linq;

 namespace ControlsAA

 {

     public class ComboBoxEx : ComboBox

     {

         TreeView lst = new TreeView();

         public ComboBoxEx()

         {

             this.DrawMode = DrawMode.OwnerDrawFixed;//只有设置这个属性为OwnerDrawFixed才可能让重画起作用

             lst.KeyUp += new KeyEventHandler(lst_KeyUp);

             lst.MouseUp += new MouseEventHandler(lst_MouseUp);

             // lst.KeyDown += new KeyEventHandler(lst_KeyDown);

             lst.Leave += new EventHandler(lst_Leave);

             lst.CheckBoxes = true;

             lst.ShowLines = false;

             lst.ShowPlusMinus = false;

             lst.ShowRootLines = false;

             this.DropDownHeight = ;

         }

         void lst_Leave(object sender, EventArgs e)

         {

             lst.Hide();

         }

         #region Property

         [Description("选定项的值"), Category("Data")]

         public List<TreeNode> SelectedItems

         {

             get

             {

                 List<TreeNode> lsttn = new List<TreeNode>();

                 foreach (TreeNode tn in lst.Nodes)

                 {

                     if (tn.Checked)

                     {

                         lsttn.Add(tn);

                     }

                 }

                 return lsttn;

             }

         }

         /// <summary>

         /// 数据源

         /// </summary>

         [Description("数据源"), Category("Data")]

         public object DataSource

         {

             get;

             set;

         }

         /// <summary>

         /// 显示字段

         /// </summary>

         [Description("显示字段"), Category("Data")]

         public string DisplayFiled

         {

             get;

             set;

         }

         /// <summary>

         /// 值字段

         /// </summary>

         [Description("值字段"), Category("Data")]

         public string ValueFiled

         {

             get;

             set;

         }

         #endregion

         public void DataBind()

         {

             this.BeginUpdate();

             if (DataSource != null)

             {

                 if (DataSource is IDataReader)

                 {

                     DataTable dataTable = new DataTable();

                     dataTable.Load(DataSource as IDataReader);

                     DataBindToDataTable(dataTable);

                 }

                 else if (DataSource is DataView || DataSource is DataSet || DataSource is DataTable)

                 {

                     DataTable dataTable = null;

                     if (DataSource is DataView)

                     {

                         dataTable = ((DataView)DataSource).ToTable();

                     }

                     else if (DataSource is DataSet)

                     {

                         dataTable = ((DataSet)DataSource).Tables[];

                     }

                     else

                     {

                         dataTable = ((DataTable)DataSource);

                     }

                     DataBindToDataTable(dataTable);

                 }

                 else if (DataSource is IEnumerable)

                 {

                     DataBindToEnumerable((IEnumerable)DataSource);

                 }

                 else

                 {

                     throw new Exception("DataSource doesn't support data type: " + DataSource.GetType().ToString());

                 }

             }

             else

             {

                 lst.Nodes.Clear();

             }

             lst.ItemHeight = this.ItemHeight;

             lst.BorderStyle = BorderStyle.FixedSingle;

             lst.Size = new Size(this.DropDownWidth, this.ItemHeight * (this.MaxDropDownItems - ) - (int)this.ItemHeight / );

             lst.Location = new Point(this.Left, this.Top + this.ItemHeight + );

             this.Parent.Controls.Add(lst);

             lst.Hide();

             this.EndUpdate();

         }

         private void DataBindToDataTable(DataTable dt)

         {

             foreach (DataRow dr in dt.Rows)

             {

                 TreeNode tn = new TreeNode();

                 if (!string.IsNullOrEmpty(DisplayFiled) && !string.IsNullOrEmpty(ValueFiled))

                 {

                     tn.Text = dr[DisplayFiled].ToString();

                     tn.Tag = dr[ValueFiled].ToString();

                 }

                 else if (string.IsNullOrEmpty(ValueFiled))

                 {

                     tn.Text = dr[DisplayFiled].ToString();

                     tn.Tag = dr[DisplayFiled].ToString();

                 }

                 else if (string.IsNullOrEmpty(DisplayFiled))

                 {

                     tn.Text = dr[ValueFiled].ToString();

                     tn.Tag = dr[ValueFiled].ToString();

                 }

                 else

                 {

                     throw new Exception("ValueFiled和DisplayFiled至少保证有一项有值");

                 }

                 tn.Checked = false;

                 lst.Nodes.Add(tn);

             }

         }

         /// <summary>

         /// 绑定到可枚举类型

         /// </summary>

         /// <param name="enumerable">可枚举类型</param>

         private void DataBindToEnumerable(IEnumerable enumerable)

         {

             IEnumerator enumerator = enumerable.GetEnumerator();

             while (enumerator.MoveNext())

             {

                 object currentObject = enumerator.Current;

                 lst.Nodes.Add(CreateListItem(currentObject));

             }

         }

         private TreeNode CreateListItem(Object obj)

         {

             TreeNode item = new TreeNode();

             if (obj is string)

             {

                 item.Text = obj.ToString();

                 item.Tag = obj.ToString();

             }

             else

             {

                 if (DisplayFiled != "")

                 {

                     item.Text = GetPropertyValue(obj, DisplayFiled);

                 }

                 else

                 {

                     item.Text = obj.ToString();

                 }

                 if (ValueFiled != "")

                 {

                     item.Tag = GetPropertyValue(obj, ValueFiled);

                 }

                 else

                 {

                     item.Tag = obj.ToString();

                 }

             }

             return item;

         }

         private string GetPropertyValue(object obj, string propertyName)

         {

             object result = null;

             result = ObjectUtil.GetPropertyValue(obj, propertyName);

             return result == null ? String.Empty : result.ToString();

         }

         #region override

         protected override void OnKeyUp(KeyEventArgs e)

         {

             base.OnKeyDown(e);

             bool Pressed = (e.Control && ((e.KeyData & Keys.A) == Keys.A));

             if (Pressed)

             {

                 this.Text = "";

                 for (int i = ; i < lst.Nodes.Count; i++)

                 {

                     lst.Nodes[i].Checked = true;

                     if (this.Text != "")

                     {

                         this.Text += ",";

                     }

                     this.Text += lst.Nodes[i].Tag;

                 }

             }

         }

         protected override void OnMouseDown(MouseEventArgs e)

         {

             this.DroppedDown = false;

         }

         protected override void OnMouseUp(MouseEventArgs e)

         {

             this.DroppedDown = false;

             lst.Focus();

         }

         protected override void OnDropDown(EventArgs e)

         {

             string strValue = this.Text;

             if (!string.IsNullOrEmpty(strValue))

             {

                 List<string> lstvalues = strValue.Split(',').ToList<string>();

                 foreach (TreeNode tn in lst.Nodes)

                 {

                     if (tn.Checked && !lstvalues.Contains(tn.Tag.ToString()) && !string.IsNullOrEmpty(tn.Tag.ToString().Trim()))

                     {

                         tn.Checked = false;

                     }

                     else if (!tn.Checked && lstvalues.Contains(tn.Tag.ToString()) && !string.IsNullOrEmpty(tn.Tag.ToString().Trim()))

                     {

                         tn.Checked = true;

                     }

                 }

             }

             lst.Show();

         }

         #endregion

         private void lst_KeyUp(object sender, KeyEventArgs e)

         {

             this.OnKeyUp(e);

         }

         private void lst_MouseUp(object sender, MouseEventArgs e)

         {

             try

             {

                 this.Text = "";

                 for (int i = ; i < lst.Nodes.Count; i++)

                 {

                     if (lst.Nodes[i].Checked)

                     {

                         if (this.Text != "")

                         {

                             this.Text += ",";

                         }

                         this.Text += lst.Nodes[i].Tag;

                     }

                 }

             }

             catch

             {

                 this.Text = "";

             }

             bool isControlPressed = (Control.ModifierKeys == Keys.Control);

             bool isShiftPressed = (Control.ModifierKeys == Keys.Shift);

             if (isControlPressed || isShiftPressed)

                 lst.Show();

             else

                 lst.Hide();

         }

     }

     /// <summary>

     /// 对象帮助类

     /// </summary>

     public class ObjectUtil

     {

         /// <summary>

         /// 获取对象的属性值

         /// </summary>

         /// <param name="obj">可能是DataRowView或一个对象</param>

         /// <param name="propertyName">属性名</param>

         /// <returns>属性值</returns>

         public static object GetPropertyValue(object obj, string propertyName)

         {

             object result = null;

             try

             {

                 if (obj is DataRow)

                 {

                     result = (obj as DataRow)[propertyName];

                 }

                 else if (obj is DataRowView)

                 {

                     result = (obj as DataRowView)[propertyName];

                 }

                 else if (obj is JObject)

                 {

                     result = (obj as JObject).Value<JValue>(propertyName).Value; //.getValue(propertyName);

                 }

                 else

                 {

                     result = GetPropertyValueFormObject(obj, propertyName);

                 }

             }

             catch (Exception)

             {

                 // 找不到此属性

             }

             return result;

         }

         /// <summary>

         /// 获取对象的属性值

         /// </summary>

         /// <param name="obj">对象</param>

         /// <param name="propertyName">属性名（"Color"、"BodyStyle"或者"Info.UserName"）</param>

         /// <returns>属性值</returns>

         private static object GetPropertyValueFormObject(object obj, string propertyName)

         {

             object rowObj = obj;

             object result = null;

             if (propertyName.IndexOf(".") > )

             {

                 string[] properties = propertyName.Split('.');

                 object tmpObj = rowObj;

                 for (int i = ; i < properties.Length; i++)

                 {

                     PropertyInfo property = tmpObj.GetType().GetProperty(properties[i], BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);

                     if (property != null)

                     {

                         tmpObj = property.GetValue(tmpObj, null);

                     }

                 }

                 result = tmpObj;

             }

             else

             {

                 PropertyInfo property = rowObj.GetType().GetProperty(propertyName, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);

                 if (property != null)

                 {

                     result = property.GetValue(rowObj, null);

                 }

             }

             return result;

         }

     }

 }