将TreeView控件绑定到ComboBox控件后，设置控件的DropDownStyle为默认的DropDown，然后选择TreeView节点后，节点文本能够显示在ComboBox中，但是如果DropDownStyle为DropDownList，则选择TreeView节点后，节点文本不会显示在ComboBox中，不知道代码还缺少什么。我的代码和运行结果如下：using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Drawing;namespace ComboBoxTreeViewControl
{
public class ComboBoxTreeView : ComboBox
{
private const int WM_LBUTTONDOWN = 0x201, WM_LBUTTONDBLCLK = 0x203;
ToolStripControlHost treeViewHost;
ToolStripDropDown dropDown;
public ComboBoxTreeView()
{
TreeView treeView = new TreeView();
treeView.AfterSelect += new TreeViewEventHandler(treeView_AfterSelect);
treeView.BorderStyle = BorderStyle.None; treeViewHost = new ToolStripControlHost(treeView);
dropDown = new ToolStripDropDown();
dropDown.Width = this.Width;
dropDown.Items.Add(treeViewHost);
}
public void treeView_AfterSelect(object sender, TreeViewEventArgs e)
{
this.Text = TreeView.SelectedNode.Text;
dropDown.Close();
}
public TreeView TreeView
{
get { return treeViewHost.Control as TreeView; }
}
private void ShowDropDown()
{
if (dropDown != null)
{
treeViewHost.Size = new Size(DropDownWidth - 2, DropDownHeight);
dropDown.Show(this, 0, this.Height);
}
}
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_LBUTTONDBLCLK || m.Msg == WM_LBUTTONDOWN)
{
ShowDropDown();
return;
}
base.WndProc(ref m);
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
if (treeViewHost != null)
{
treeViewHost.Dispose();
treeViewHost = null;
} if (dropDown != null)
{
dropDown.Dispose();
dropDown = null;
}
}
base.Dispose(disposing);
}
}
}
截图了，但是不知道怎么贴进来。
using System.Text;
using System.Windows.Forms;
using System.Drawing;namespace ComboBoxTreeViewControl
{
public class ComboBoxTreeView : ComboBox
{
private const int WM_LBUTTONDOWN = 0x201, WM_LBUTTONDBLCLK = 0x203;
ToolStripControlHost treeViewHost;
ToolStripDropDown dropDown;
public ComboBoxTreeView()
{
TreeView treeView = new TreeView();
treeView.AfterSelect += new TreeViewEventHandler(treeView_AfterSelect);
treeView.BorderStyle = BorderStyle.None; treeViewHost = new ToolStripControlHost(treeView);
dropDown = new ToolStripDropDown();
dropDown.Width = this.Width;
dropDown.Items.Add(treeViewHost);
}
public void treeView_AfterSelect(object sender, TreeViewEventArgs e)
{
this.Text = TreeView.SelectedNode.Text;
dropDown.Close();
}
public TreeView TreeView
{
get { return treeViewHost.Control as TreeView; }
}
private void ShowDropDown()
{
if (dropDown != null)
{
treeViewHost.Size = new Size(DropDownWidth - 2, DropDownHeight);
dropDown.Show(this, 0, this.Height);
}
}
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_LBUTTONDBLCLK || m.Msg == WM_LBUTTONDOWN)
{
ShowDropDown();
return;
}
base.WndProc(ref m);
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
if (treeViewHost != null)
{
treeViewHost.Dispose();
treeViewHost = null;
} if (dropDown != null)
{
dropDown.Dispose();
dropDown = null;
}
}
base.Dispose(disposing);
}
}
}
截图了，但是不知道怎么贴进来。
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你先定义一个数据源属性,把数据添加到TreeView显示,同时也要添加到ComboBox的,选择树节点时,
写 base.SelectedValue
就好了！！！
base.SelectedValue=TreeView.SelectedNode.Text
另外，MiloSoft说的定义数据源属性，是怎么定义的？谢谢指教！
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;namespace WindowsApplication26
{
public class ComboBoxTreeView : ComboBox
{
private const int WM_LBUTTONDOWN = 0x201, WM_LBUTTONDBLCLK = 0x203;
ToolStripControlHost treeViewHost;
ToolStripDropDown dropDown;
public ComboBoxTreeView()
{
TreeView treeView = new TreeView();
treeView.AfterSelect += new TreeViewEventHandler(treeView_AfterSelect);
treeView.BorderStyle = BorderStyle.None; treeViewHost = new ToolStripControlHost(treeView);
dropDown = new ToolStripDropDown();
dropDown.Width = this.Width;
dropDown.Items.Add(treeViewHost);
this.DataSourceChanged += new EventHandler(ComboBoxTreeView_DataSourceChanged);
} void ComboBoxTreeView_DataSourceChanged(object sender, EventArgs e)
{
if (base.DataSource is List<string>)
{
List<string> items = base.DataSource as List<string>;
foreach (string str in items)
{
TreeView.Nodes.Add(str);
}
}
}
public void treeView_AfterSelect(object sender, TreeViewEventArgs e)
{
//如果设定了base.ValueMember 才可以用 SelectedValue
this.SelectedItem = TreeView.SelectedNode.Text;
dropDown.Close();
}
public TreeView TreeView
{
get { return treeViewHost.Control as TreeView; }
}
private void ShowDropDown()
{
if (dropDown != null)
{
treeViewHost.Size = new Size(DropDownWidth - 2, DropDownHeight);
dropDown.Show(this, 0, this.Height);
}
}
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_LBUTTONDBLCLK || m.Msg == WM_LBUTTONDOWN)
{
ShowDropDown();
return;
}
base.WndProc(ref m);
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
if (treeViewHost != null)
{
treeViewHost.Dispose();
treeViewHost = null;
} if (dropDown != null)
{
dropDown.Dispose();
dropDown = null;
}
}
base.Dispose(disposing);
} }
}
2.使用的代码
private void Form1_Load(object sender, EventArgs e)
{
List<string> datasource = new List<string>();
datasource.Add("节点0");
datasource.Add("节点1");
datasource.Add("节点2");
datasource.Add("节点3");
comboBoxTreeView1.DataSource = datasource;
}
{
using (OracleConnection conn = new OracleConnection("Data Source=ORCL;User ID=TODAI;Password=TODAI"))
{
DataTable dt = new DataTable();
OracleDataAdapter da = new OracleDataAdapter(sql,conn);
da.Fill(dt);
return dt;
}
}private void yuangongjiansuo_Load(object sender, EventArgs e)
{
CreateTable();
CreateTree();
}
private DataTable dtTree = null;
private DataView dv = null; private void CreateTable()
{
OracleConnection conn = new OracleConnection("Data Source=orcl;User ID=TODAI;Password=TODAI");
conn.Open();
string sss = "Select DEPTID,DEPTNAME,PARENT_DEPT_ID from HR_DEPARTMENT";
OracleDataAdapter kkk = new OracleDataAdapter(sss, conn);
DataSet ds = new DataSet();
kkk.Fill(ds);
dtTree = ds.Tables[0];
}
private void CreateTree()
{
dv = dtTree.DefaultView;
dv.Sort = "PARENT_DEPT_ID ASC";
DataRowView[] arrDRV = dv.FindRows(0);
if (arrDRV.Length == 0) return;
TreeNode tnNew = null;
foreach (DataRowView drv in arrDRV)
{
tnNew = treeView1.Nodes.Add(drv.Row["DEPTNAME"].ToString());
tnNew.Tag = drv.Row["DEPTID"].ToString();
CreateTreeNode(ref tnNew);
}
this.treeView1.ExpandAll();
}
private void CreateTreeNode(ref TreeNode tnParent)
{
DataRowView[] arrDRV = dv.FindRows(tnParent.Tag);
if (arrDRV.Length == 0) return;
TreeNode tnNew = null;
foreach (DataRowView drv in arrDRV)
{
tnNew = tnParent.Nodes.Add(drv.Row["DEPTNAME"].ToString());
tnNew.Tag = drv.Row["DEPTID"].ToString();
CreateTreeNode(ref tnNew);
}
} 我直接从数据库调用的代码，希望对LZ有帮助。
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
using System.Data;
using System.ComponentModel;namespace ComboBoxTreeViewCOM
{
public class ComboBoxTreeView : ComboBox
{
private const int WM_LBUTTONDOWN = 0x201;
private const int WM_LBUTTONDBLCLK = 0x203;
private ToolStripControlHost m_pTreeViewControlHost = null;
private ToolStripDropDown m_pToolStripDropDown = null;
private DataView m_pDataView_TreeView = null;
private string m_strIDControl = string.Empty;
private string m_strIDParent = string.Empty;
private string m_strShowName = string.Empty;
private bool m_isParentNodeSelectable = false;
private bool m_isAllowNullValue = true; /// <summary>
/// 构造函数
/// </summary>
public ComboBoxTreeView()
{
TreeView oTreeView = new TreeView();
oTreeView.AfterSelect += new TreeViewEventHandler(TreeView_AfterSelect);
oTreeView.BorderStyle = BorderStyle.None; this.m_pTreeViewControlHost = new ToolStripControlHost(oTreeView);
this.m_pToolStripDropDown = new ToolStripDropDown();
this.m_pToolStripDropDown.Width = this.Width;
this.m_pToolStripDropDown.Items.Add(m_pTreeViewControlHost);
this.DataSourceChanged += new EventHandler(ComboBoxTreeView_DataSourceChanged);
} #region 组件公共属性
/// <summary>
/// 获取TreeView控件
/// </summary>
[Description("获取TreeView控件")]
public TreeView TreeView
{
get
{
return m_pTreeViewControlHost.Control as TreeView;
}
} /// <summary>
/// 控件下拉框显示内容名称
/// </summary>
[Description("控件下拉框显示内容名称")]
[DefaultValue("string.Empty")]
public string ShowName
{
get
{
return this.m_strShowName;
}
set
{
this.m_strShowName = value;
}
} /// <summary>
/// 组件IDControl属性
/// </summary>
[Description("组件IDControl属性")]
[DefaultValue("string.Empty")]
public string IDControl
{
get
{
return this.m_strIDControl;
}
set
{
this.m_strIDControl =value;
}
} /// <summary>
/// 组件ParentID属性
/// </summary>
[Description("组件ParentID属性")]
[DefaultValue("string.Empty")]
public string IDParent
{
get
{
return this.m_strIDParent;
}
set
{
this.m_strIDParent = value;
}
} /// <summary>
/// 父节点是否可选
/// </summary>
[Description("父节点是否可选")]
[DefaultValue("false")]
public bool ParentNodeSelectable
{
get
{
return this.m_isParentNodeSelectable;
}
set
{
this.m_isParentNodeSelectable = value;
}
} /// <summary>
/// 是否允许空值
/// </summary>
[Description("是否允许空值")]
[DefaultValue("true")]
public bool AllowNullValue
{
get
{
return this.m_isAllowNullValue;
}
set
{
this.m_isAllowNullValue = value;
}
}
#endregion /// <summary>
/// 重载ComboBox的DataSourceChanged事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ComboBoxTreeView_DataSourceChanged(object sender, EventArgs e)
{
try
{
DataTable pDataTable_TreeView = null;
DataRowView[] arrDataRowView = null;
TreeNode pTreeNode_New = null; pDataTable_TreeView = this.DataSource as DataTable; if (pDataTable_TreeView == null)
return; m_pDataView_TreeView = pDataTable_TreeView.DefaultView;
m_pDataView_TreeView.Sort = m_strIDParent + @" ASC"; //添加用地分类，从0开始
arrDataRowView = m_pDataView_TreeView.FindRows(0);
if (arrDataRowView.Length > 0)
{
foreach (DataRowView pDataRowView in arrDataRowView)
{
pTreeNode_New = this.TreeView.Nodes.Add(pDataRowView.Row[m_strShowName].ToString());
pTreeNode_New.Tag = pDataRowView.Row[m_strIDControl].ToString();
CreateTreeNode(ref pTreeNode_New);
}
} ///展开所有节点
this.TreeView.ExpandAll();
}
catch
{
}
} /// <summary>
/// 添加节点
/// </summary>
/// <param name="pTreeNode_Parent"></param>
private void CreateTreeNode(ref TreeNode pTreeNode_Parent)
{
try
{
DataRowView[] arrDataRowView_TreeNodeTag = m_pDataView_TreeView.FindRows(pTreeNode_Parent.Tag);
if (arrDataRowView_TreeNodeTag.Length == 0)
return; TreeNode pTreeNode_New = null;
foreach (DataRowView pDataRowView in arrDataRowView_TreeNodeTag)
{
pTreeNode_New = pTreeNode_Parent.Nodes.Add(pDataRowView.Row[m_strShowName].ToString());
pTreeNode_New.Tag = pDataRowView.Row[m_strIDControl].ToString();
CreateTreeNode(ref pTreeNode_New);
}
}
catch
{
}
} /// <summary>
/// 重构TreeView控件的AfterSelect事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public void TreeView_AfterSelect(object sender, TreeViewEventArgs e)
{
try
{
if (this.m_isParentNodeSelectable == false && TreeView.SelectedNode != null && (TreeView.SelectedNode.Nodes == null || TreeView.SelectedNode.Nodes.Count == 0))
{
//如果设定了base.ValueMember才可以用SelectedValue
if (string.IsNullOrEmpty(this.ValueMember) == false)
{
this.SelectedValue = TreeView.SelectedNode.Text;
}
else
{
this.SelectedItem = TreeView.SelectedNode.Text;
}
m_pToolStripDropDown.Close();
}
else if (this.m_isParentNodeSelectable == true && TreeView.SelectedNode != null)
{
//如果设定了base.ValueMember才可以用SelectedValue
if (string.IsNullOrEmpty(this.ValueMember) == false)
{
this.SelectedValue = TreeView.SelectedNode.Text;
}
else
{
this.SelectedItem = TreeView.SelectedNode.Text;
}
m_pToolStripDropDown.Close();
}
}
catch
{
}
} /// <summary>
/// 显示下拉框
/// </summary>
private void ShowDropDown()
{
if (m_pToolStripDropDown != null)
{
m_pTreeViewControlHost.Size = new Size(DropDownWidth - 2, DropDownHeight);
m_pToolStripDropDown.Show(this, 0, this.Height);
}
} /// <summary>
/// 重载WndProc方法
/// </summary>
/// <param name="m"></param>
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_LBUTTONDBLCLK || m.Msg == WM_LBUTTONDOWN)
{
ShowDropDown();
return;
}
base.WndProc(ref m);
} /// <summary>
/// 重载Dispose方法
/// </summary>
/// <param name="disposing"></param>
protected override void Dispose(bool disposing)
{
if (disposing)
{
if (m_pTreeViewControlHost != null)
{
m_pTreeViewControlHost.Dispose();
m_pTreeViewControlHost = null;
} if (m_pToolStripDropDown != null)
{
m_pToolStripDropDown.Dispose();
m_pToolStripDropDown = null;
}
}
base.Dispose(disposing);
}
}
}
private void Form1_Load(object sender, EventArgs e)
{
BindData();
}
private void BindData()
{
DataTable pDataTable_TreeView = GetTable("SELECT DM, DM & NAME As DMNAME , SJDM FROM ZD_TDLYFL ORDER BY DM, JB, XH");
if (pDataTable_TreeView != null)
{
this.comboBoxTreeView1.DataSource = pDataTable_TreeView;
this.comboBoxAdvTree1.DataSource = pDataTable_TreeView;
this.comboBoxAdvTreeViewEx1.DataSource = pDataTable_TreeView;
}
}private DataTable GetTable(string strSQL)
{
OleDbConnection pOleDbConnection; try
{
if (ConnectAccessDatabase("", out pOleDbConnection) && pOleDbConnection != null)
{
DataTable pDataTable = new DataTable();
OleDbDataAdapter pOleDbDataAdapter = new OleDbDataAdapter(strSQL, pOleDbConnection);
pOleDbDataAdapter.Fill(pDataTable);
return pDataTable;
}
else
{
return null;
}
}
catch
{
return null;
}
}#region 打开Access数据库连接，并返回OleDbConnection连接对象
public static bool ConnectAccessDatabase(string strAccessFullPath,
out OleDbConnection oDBConn)
{
string strConnection = string.Empty; try
{
strConnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + & strAccessFullPath + ";Jet OLEDB:Engine Type=5;"; oDBConn = new OleDbConnection();
oDBConn.ConnectionString = strConnection;
oDBConn.Open(); if (oDBConn != null && oDBConn.State == ConnectionState.Open)
{
return true;
}
else
{
oDBConn = null;
return false;
}
}
catch
{
oDBConn = null;
return false;
}
}
#endregion