TreeView コンストラクタ
アセンブリ: System.Web (system.web.dll 内)
構文
解説
TreeView コンストラクタを使用して、TreeView クラスの新しいインスタンスを作成し、初期化します。TreeView コントロールをページに動的に追加するには、新しい TreeView オブジェクトを作成してそのプロパティを設定し、コンテナ コントロール (PlaceHolder コントロールなど) の Control.Controls コレクションに追加します。
このセクションには、2 つのコード例が含まれています。TreeView コンストラクタを使用して、TreeView コントロールをページに動的に追加する方法を最初のコード例に示します。最初のコード例に対応したサンプル XML データを 2 番目のコード例に示します。
TreeView コンストラクタを使用して、TreeView コントロールをページに動的に追加する方法を次のコード例に示します。この例を正常に動作させるには、このコード例の後に示すサンプル XML データを、Book.xml という名前のファイルにコピーする必要があります。
<%@ Page Language="VB" %> <script runat="server"> Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) ' Create a new TreeView control. Dim NewTree As New TreeView ' Set the properties of the TreeView control. NewTree.ID = "BookTreeView" NewTree.DataSourceID = "BookXmlDataSource" ' Create the tree node binding relationship. ' Create the root node binding. Dim RootBinding As New TreeNodeBinding RootBinding.DataMember = "Book" RootBinding.TextField = "Title" ' Create the parent node binding. Dim ParentBinding As New TreeNodeBinding ParentBinding.DataMember = "Chapter" ParentBinding.TextField = "Heading" ' Create the leaf node binding. Dim LeafBinding As New TreeNodeBinding LeafBinding.DataMember = "Section" LeafBinding.TextField = "Heading" ' Add bindings to the DataBindings collection. NewTree.DataBindings.Add(RootBinding) NewTree.DataBindings.Add(ParentBinding) NewTree.DataBindings.Add(LeafBinding) ' Manually register the event handler for the SelectedNodeChanged event. AddHandler NewTree.SelectedNodeChanged, AddressOf Node_Change ' Add the TreeView control to the Controls collection of the PlaceHolder control. ControlPlaceHolder.Controls.Add(NewTree) End Sub Sub Node_Change(ByVal sender As Object, ByVal e As EventArgs) ' Retrieve the TreeView control from the Controls collection of the PlaceHolder control. Dim LocalTree As TreeView = CType(ControlPlaceHolder.FindControl("BookTreeView"), TreeView) ' Display the selected node. Message.Text = "You selected: " & LocalTree.SelectedNode.Text End Sub </script> <html> <body> <form runat="server"> <h3>TreeView Constructor Example</h3> <asp:PlaceHolder id="ControlPlaceHolder" runat="server"> </asp:PlaceHolder> <asp:XmlDataSource id="BookXmlDataSource" DataFile="Book.xml" runat="server"> </asp:XmlDataSource> <br><br> <asp:Label id="Message" runat="server"/> </form> </body> </html>
<%@ Page Language="C#" %> <script runat="server"> void Page_Load(Object sender, EventArgs e) { // Create a new TreeView control. TreeView NewTree = new TreeView(); // Set the properties of the TreeView control. NewTree.ID = "BookTreeView"; NewTree.DataSourceID = "BookXmlDataSource"; // Create the tree node binding relationship. // Create the root node binding. TreeNodeBinding RootBinding = new TreeNodeBinding(); RootBinding.DataMember = "Book"; RootBinding.TextField = "Title"; // Create the parent node binding. TreeNodeBinding ParentBinding = new TreeNodeBinding(); ParentBinding.DataMember = "Chapter"; ParentBinding.TextField = "Heading"; // Create the leaf node binding. TreeNodeBinding LeafBinding = new TreeNodeBinding(); LeafBinding.DataMember = "Section"; LeafBinding.TextField = "Heading"; // Add bindings to the DataBindings collection. NewTree.DataBindings.Add(RootBinding); NewTree.DataBindings.Add(ParentBinding); NewTree.DataBindings.Add(LeafBinding); // Manually register the event handler for the SelectedNodeChanged event. NewTree.SelectedNodeChanged += new EventHandler(this.Node_Change); // Add the TreeView control to the Controls collection of the PlaceHolder control. ControlPlaceHolder.Controls.Add(NewTree); } void Node_Change(Object sender, EventArgs e) { // Retrieve the TreeView control from the Controls collection of the PlaceHolder control. TreeView LocalTree = (TreeView)ControlPlaceHolder.FindControl("BookTreeView"); // Display the selected node. Message.Text = "You selected: " + LocalTree.SelectedNode.Text; } </script> <html> <body> <form runat="server"> <h3>TreeView Constructor Example</h3> <asp:PlaceHolder id="ControlPlaceHolder" runat="server"> </asp:PlaceHolder> <asp:XmlDataSource id="BookXmlDataSource" DataFile="Book.xml" runat="server"> </asp:XmlDataSource> <br><br> <asp:Label id="Message" runat="server"/> </form> </body> </html>
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
TreeView コンストラクタ
アセンブリ: System.Windows.Forms (system.windows.forms.dll 内)
構文
使用例
TreeView の折りたたみの状態を変更して、チェックされているノードを表示する方法を次のコード例に示します。まず、すべてのノードが展開され、BeforeCollapse イベントのイベント ハンドラが追加されます。次に、すべてのノードが折りたたまれます。BeforeCollapse イベント ハンドラは、指定したノードに、チェックされている子ノードがあるかどうかを確認します。チェックされている子ノードがある場合、そのノードの折りたたみはキャンセルされます。次に、ノードの横にあるマイナス記号がクリックされたときに通常のノードを折りたためるようにするため、BeforeCollapse イベント ハンドラが削除されます。
BeforeExpand イベントを処理してこの動作を実装することもできます。詳細については、該当するトピックの例を参照してください。
Imports System Imports System.Drawing Imports System.Windows.Forms Public Class Form1 Inherits Form Private treeView1 As TreeView Private showCheckedNodesButton As Button Public Sub New() treeView1 = New TreeView showCheckedNodesButton = New Button Me.SuspendLayout() ' Initialize treeView1. treeView1.Location = New Point(0, 25) treeView1.Size = New Size(292, 248) treeView1.Anchor = AnchorStyles.Top Or AnchorStyles.Left Or AnchorStyles.Bottom Or AnchorStyles.Right treeView1.CheckBoxes = True ' Add nodes to treeView1. Dim node As TreeNode Dim x As Integer For x = 0 To 3 ' Add a root node. node = treeView1.Nodes.Add(String.Format("Node{0}", x * 4)) Dim y As Integer For y = 1 To 4 ' Add a node as a child of the previously added node. node = node.Nodes.Add(String.Format("Node{0}", x * 4 + y)) Next y Next x ' Set the checked state of one of the nodes to ' demonstrate the showCheckedNodesButton button behavior. treeView1.Nodes(1).Nodes(0).Nodes(0).Checked = True ' Initialize showCheckedNodesButton. showCheckedNodesButton.Size = New Size(144, 24) showCheckedNodesButton.Text = "Show Checked Nodes" AddHandler showCheckedNodesButton.Click, AddressOf showCheckedNodesButton_Click ' Initialize the form. Me.ClientSize = New Size(292, 273) Me.Controls.AddRange(New Control() {showCheckedNodesButton, treeView1}) Me.ResumeLayout(False) End Sub 'New <STAThreadAttribute()> _ Shared Sub Main() Application.Run(New Form1()) End Sub 'Main Private Sub showCheckedNodesButton_Click(ByVal sender As Object, ByVal e As EventArgs) ' Disable redrawing of treeView1 to prevent flickering ' while changes are made. treeView1.BeginUpdate() ' Collapse all nodes of treeView1. treeView1.ExpandAll() ' Add the CheckForCheckedChildren event handler to the BeforeExpand event. AddHandler treeView1.BeforeCollapse, AddressOf CheckForCheckedChildren ' Expand all nodes of treeView1. Nodes without checked children are ' prevented from expanding by the checkForCheckedChildren event handler. treeView1.CollapseAll() ' Remove the checkForCheckedChildren event handler from the BeforeExpand ' event so manual node expansion will work correctly. RemoveHandler treeView1.BeforeCollapse, AddressOf CheckForCheckedChildren ' Enable redrawing of treeView1. treeView1.EndUpdate() End Sub 'showCheckedNodesButton_Click ' Prevent collapse of a node that has checked child nodes. Private Sub CheckForCheckedChildren(ByVal sender As Object, ByVal e As TreeViewCancelEventArgs) If HasCheckedChildNodes(e.Node) Then e.Cancel = True End If End Sub 'CheckForCheckedChildren ' Returns a value indicating whether the specified ' TreeNode has checked child nodes. Private Function HasCheckedChildNodes(ByVal node As TreeNode) As Boolean If node.Nodes.Count = 0 Then Return False End If Dim childNode As TreeNode For Each childNode In node.Nodes If childNode.Checked Then Return True End If ' Recursively check the children of the current child node. If HasCheckedChildNodes(childNode) Then Return True End If Next childNode Return False End Function 'HasCheckedChildNodes End Class 'Form1
using System; using System.Drawing; using System.Windows.Forms; public class Form1 : Form { private TreeView treeView1; private Button showCheckedNodesButton; private TreeViewCancelEventHandler checkForCheckedChildren; public Form1() { treeView1 = new TreeView(); showCheckedNodesButton = new Button(); checkForCheckedChildren = new TreeViewCancelEventHandler(CheckForCheckedChildrenHandler); this.SuspendLayout(); // Initialize treeView1. treeView1.Location = new Point(0, 25); treeView1.Size = new Size(292, 248); treeView1.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Bottom | AnchorStyles.Right; treeView1.CheckBoxes = true; // Add nodes to treeView1. TreeNode node; for (int x = 0; x < 3; ++x) { // Add a root node. node = treeView1.Nodes.Add(String.Format("Node{0}", x*4)); for (int y = 1; y < 4; ++y) { // Add a node as a child of the previously added node. node = node.Nodes.Add(String.Format("Node{0}", x*4 + y)); } } // Set the checked state of one of the nodes to // demonstrate the showCheckedNodesButton button behavior. treeView1.Nodes[1].Nodes[0].Nodes[0].Checked = true; // Initialize showCheckedNodesButton. showCheckedNodesButton.Size = new Size(144, 24); showCheckedNodesButton.Text = "Show Checked Nodes"; showCheckedNodesButton.Click += new EventHandler(showCheckedNodesButton_Click); // Initialize the form. this.ClientSize = new Size(292, 273); this.Controls.AddRange(new Control[] { showCheckedNodesButton, treeView1 } ); this.ResumeLayout(false); } [STAThreadAttribute()] static void Main() { Application.Run(new Form1()); } private void showCheckedNodesButton_Click(object sender, EventArgs e) { // Disable redrawing of treeView1 to prevent flickering // while changes are made. treeView1.BeginUpdate(); // Collapse all nodes of treeView1. treeView1.ExpandAll(); // Add the checkForCheckedChildren event handler to the BeforeExpand event. treeView1.BeforeCollapse += checkForCheckedChildren; // Expand all nodes of treeView1. Nodes without checked children are // prevented from expanding by the checkForCheckedChildren event handler. treeView1.CollapseAll(); // Remove the checkForCheckedChildren event handler from the BeforeExpand // event so manual node expansion will work correctly. treeView1.BeforeCollapse -= checkForCheckedChildren; // Enable redrawing of treeView1. treeView1.EndUpdate(); } // Prevent collapse of a node that has checked child nodes. private void CheckForCheckedChildrenHandler(object sender, TreeViewCancelEventArgs e) { if (HasCheckedChildNodes(e.Node)) e.Cancel = true; } // Returns a value indicating whether the specified // TreeNode has checked child nodes. private bool HasCheckedChildNodes(TreeNode node) { if (node.Nodes.Count == 0) return false; foreach (TreeNode childNode in node.Nodes) { if (childNode.Checked) return true; // Recursively check the children of the current child node. if (HasCheckedChildNodes(childNode)) return true; } return false; } }
#using <System.dll> #using <System.Windows.Forms.dll> #using <System.Drawing.dll> using namespace System; using namespace System::Drawing; using namespace System::Windows::Forms; public ref class Form1: public Form { private: TreeView^ treeView1; Button^ showCheckedNodesButton; TreeViewCancelEventHandler^ checkForCheckedChildren; public: Form1() { treeView1 = gcnew TreeView; showCheckedNodesButton = gcnew Button; checkForCheckedChildren = gcnew TreeViewCancelEventHandler( this, &Form1::CheckForCheckedChildrenHandler ); this->SuspendLayout(); // Initialize treeView1. treeView1->Location = Point(0,25); treeView1->Size = System::Drawing::Size( 292, 248 ); treeView1->Anchor = static_cast<AnchorStyles>(AnchorStyles::Top | AnchorStyles::Left | AnchorStyles::Bottom | AnchorStyles::Right); treeView1->CheckBoxes = true; // Add nodes to treeView1. TreeNode^ node; for ( int x = 0; x < 3; ++x ) { // Add a root node. node = treeView1->Nodes->Add( String::Format( "Node{0}", x * 4 ) ); for ( int y = 1; y < 4; ++y ) { // Add a node as a child of the previously added node. node = node->Nodes->Add( String::Format( "Node{0}", x * 4 + y ) ); } } // Set the checked state of one of the nodes to // demonstrate the showCheckedNodesButton button behavior. treeView1->Nodes[ 1 ]->Nodes[ 0 ]->Nodes[ 0 ]->Checked = true; // Initialize showCheckedNodesButton. showCheckedNodesButton->Size = System::Drawing::Size( 144, 24 ); showCheckedNodesButton->Text = "Show Checked Nodes"; showCheckedNodesButton->Click += gcnew EventHandler( this, &Form1::showCheckedNodesButton_Click ); // Initialize the form. this->ClientSize = System::Drawing::Size( 292, 273 ); array<Control^>^temp1 = {showCheckedNodesButton,treeView1}; this->Controls->AddRange( temp1 ); this->ResumeLayout( false ); } private: void showCheckedNodesButton_Click( Object^ /*sender*/, EventArgs^ /*e*/ ) { // Disable redrawing of treeView1 to prevent flickering // while changes are made. treeView1->BeginUpdate(); // Collapse all nodes of treeView1. treeView1->ExpandAll(); // Add the checkForCheckedChildren event handler to the BeforeExpand event. treeView1->BeforeCollapse += checkForCheckedChildren; // Expand all nodes of treeView1. Nodes without checked children are // prevented from expanding by the checkForCheckedChildren event handler. treeView1->CollapseAll(); // Remove the checkForCheckedChildren event handler from the BeforeExpand // event so manual node expansion will work correctly. treeView1->BeforeCollapse -= checkForCheckedChildren; // Enable redrawing of treeView1. treeView1->EndUpdate(); } // Prevent collapse of a node that has checked child nodes. void CheckForCheckedChildrenHandler( Object^ /*sender*/, TreeViewCancelEventArgs^ e ) { if ( HasCheckedChildNodes( e->Node ) ) e->Cancel = true; } // Returns a value indicating whether the specified // TreeNode has checked child nodes. bool HasCheckedChildNodes( TreeNode^ node ) { if ( node->Nodes->Count == 0 ) return false; System::Collections::IEnumerator^ myEnum = node->Nodes->GetEnumerator(); while ( myEnum->MoveNext() ) { TreeNode^ childNode = safe_cast<TreeNode^>(myEnum->Current); if ( childNode->Checked ) return true; // Recursively check the children of the current child node. if ( HasCheckedChildNodes( childNode ) ) return true; } return false; } }; int main() { Application::Run( gcnew Form1 ); }
import System.*; import System.Drawing.*; import System.Windows.Forms.*; public class Form1 extends Form { private TreeView treeView1; private Button showCheckedNodesButton; private TreeViewCancelEventHandler checkForCheckedChildren; public Form1() { treeView1 = new TreeView(); showCheckedNodesButton = new Button(); checkForCheckedChildren = new TreeViewCancelEventHandler(CheckForCheckedChildrenHandler); this.SuspendLayout(); // Initialize treeView1. treeView1.set_Location(new Point(0, 25)); treeView1.set_Size(new Size(292, 248)); treeView1.set_Anchor(AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Bottom | AnchorStyles.Right); treeView1.set_CheckBoxes(true); // Add nodes to treeView1. TreeNode node; for (int x = 0; x < 3; ++x) { // Add a root node. node = treeView1.get_Nodes().Add(String.Format ("Node{0}", (Int32)(x * 4))); for (int y = 1; y < 4; ++y) { // Add a node as a child of the previously added node. node = node.get_Nodes().Add(String.Format ("Node{0}", (Int32)(x * 4 + y))); } } // Set the checked state of one of the nodes to // demonstrate the showCheckedNodesButton button behavior. treeView1.get_Nodes().get_Item(1).get_Nodes().get_Item(0). get_Nodes().get_Item(0).set_Checked(true); // Initialize showCheckedNodesButton. showCheckedNodesButton.set_Size(new Size(144, 24)); showCheckedNodesButton.set_Text("Show Checked Nodes"); showCheckedNodesButton.add_Click(new EventHandler (showCheckedNodesButton_Click)); // Initialize the form. this.set_ClientSize(new Size(292, 273)); this.get_Controls().AddRange(new Control[] { showCheckedNodesButton, treeView1 }); this.ResumeLayout(false); } //Form1 public static void main(String[] args) { Application.Run(new Form1()); } //main private void showCheckedNodesButton_Click(Object sender, EventArgs e) { // Disable redrawing of treeView1 to prevent flickering // while changes are made. treeView1.BeginUpdate(); // Collapse all nodes of treeView1. treeView1.ExpandAll(); // Add the checkForCheckedChildren event handler to the // BeforeExpand event. treeView1.add_BeforeCollapse(checkForCheckedChildren); // Expand all nodes of treeView1. Nodes without checked children are // prevented from expanding by the checkForCheckedChildren event handler. treeView1.CollapseAll(); // Remove the checkForCheckedChildren event handler from the // BeforeExpand event so manual node expansion will work correctly. treeView1.remove_BeforeCollapse(checkForCheckedChildren); // Enable redrawing of treeView1. treeView1.EndUpdate(); } //showCheckedNodesButton_Click // Prevent collapse of a node that has checked child nodes. private void CheckForCheckedChildrenHandler(Object sender, TreeViewCancelEventArgs e) { if (HasCheckedChildNodes(e.get_Node())) { e.set_Cancel(true); } } //CheckForCheckedChildrenHandler // Returns a value indicating whether the specified // TreeNode has checked child nodes. private boolean HasCheckedChildNodes(TreeNode node) { if (node.get_Nodes().get_Count() == 0) { return false; } for (int iCtr = 0; iCtr < node.get_Nodes().get_Count(); iCtr++) { TreeNode childNode = node.get_Nodes().get_Item(iCtr); if (childNode.get_Checked()) { return true; } // Recursively check the children of the current child node. if (HasCheckedChildNodes(childNode)) { return true; } } return false; } //HasCheckedChildNodes } //Form1
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
- TreeView コンストラクタのページへのリンク