TreeNodeCollection Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Represents a collection of TreeNode objects.
public ref class TreeNodeCollection : System::Collections::IList
public class TreeNodeCollection : System.Collections.IList
type TreeNodeCollection = class
interface IList
interface ICollection
interface IEnumerable
Public Class TreeNodeCollection
Implements IList
- Inheritance
-
TreeNodeCollection
- Implements
Examples
The following code example displays customer information in a TreeView control. The root tree nodes display customer names, and the child tree nodes display the order numbers assigned to each customer. In this example, 1,000 customers are displayed with 15 orders each. The repainting of the TreeView is suppressed by using the BeginUpdate and EndUpdate methods, and a wait Cursor is displayed while the TreeView creates and paints the TreeNode objects. This example requires that you have a Customer
object that can hold a collection of Order
objects. It also requires that you have created an instance of a TreeView control on a Form.
// The basic Customer class.
ref class Customer: public System::Object
{
private:
String^ custName;
protected:
ArrayList^ custOrders;
public:
Customer( String^ customername )
{
custName = "";
custOrders = gcnew ArrayList;
this->custName = customername;
}
property String^ CustomerName
{
String^ get()
{
return this->custName;
}
void set( String^ value )
{
this->custName = value;
}
}
property ArrayList^ CustomerOrders
{
ArrayList^ get()
{
return this->custOrders;
}
}
};
// End Customer class
// The basic customer Order class.
ref class Order: public System::Object
{
private:
String^ ordID;
public:
Order( String^ orderid )
{
ordID = "";
this->ordID = orderid;
}
property String^ OrderID
{
String^ get()
{
return this->ordID;
}
void set( String^ value )
{
this->ordID = value;
}
}
};
// End Order class
void FillMyTreeView()
{
// Add customers to the ArrayList of Customer objects.
for ( int x = 0; x < 1000; x++ )
{
customerArray->Add( gcnew Customer( "Customer " + x ) );
}
// Add orders to each Customer object in the ArrayList.
IEnumerator^ myEnum = customerArray->GetEnumerator();
while ( myEnum->MoveNext() )
{
Customer^ customer1 = safe_cast<Customer^>(myEnum->Current);
for ( int y = 0; y < 15; y++ )
{
customer1->CustomerOrders->Add( gcnew Order( "Order " + y ) );
}
}
// Display a wait cursor while the TreeNodes are being created.
::Cursor::Current = gcnew System::Windows::Forms::Cursor( "MyWait.cur" );
// Suppress repainting the TreeView until all the objects have been created.
treeView1->BeginUpdate();
// Clear the TreeView each time the method is called.
treeView1->Nodes->Clear();
// Add a root TreeNode for each Customer object in the ArrayList.
myEnum = customerArray->GetEnumerator();
while ( myEnum->MoveNext() )
{
Customer^ customer2 = safe_cast<Customer^>(myEnum->Current);
treeView1->Nodes->Add( gcnew TreeNode( customer2->CustomerName ) );
// Add a child treenode for each Order object in the current Customer object.
IEnumerator^ myEnum = customer2->CustomerOrders->GetEnumerator();
while ( myEnum->MoveNext() )
{
Order^ order1 = safe_cast<Order^>(myEnum->Current);
treeView1->Nodes[ customerArray->IndexOf( customer2 ) ]->Nodes->Add( gcnew TreeNode( customer2->CustomerName + "." + order1->OrderID ) );
}
}
// Reset the cursor to the default for all controls.
::Cursor::Current = Cursors::Default;
// Begin repainting the TreeView.
treeView1->EndUpdate();
}
// The basic Customer class.
public class Customer : System.Object
{
private string custName = "";
protected ArrayList custOrders = new ArrayList();
public Customer(string customername)
{
this.custName = customername;
}
public string CustomerName
{
get{return this.custName;}
set{this.custName = value;}
}
public ArrayList CustomerOrders
{
get{return this.custOrders;}
}
} // End Customer class
// The basic customer Order class.
public class Order : System.Object
{
private string ordID = "";
public Order(string orderid)
{
this.ordID = orderid;
}
public string OrderID
{
get{return this.ordID;}
set{this.ordID = value;}
}
} // End Order class
// Create a new ArrayList to hold the Customer objects.
private ArrayList customerArray = new ArrayList();
private void FillMyTreeView()
{
// Add customers to the ArrayList of Customer objects.
for(int x=0; x<1000; x++)
{
customerArray.Add(new Customer("Customer" + x.ToString()));
}
// Add orders to each Customer object in the ArrayList.
foreach(Customer customer1 in customerArray)
{
for(int y=0; y<15; y++)
{
customer1.CustomerOrders.Add(new Order("Order" + y.ToString()));
}
}
// Display a wait cursor while the TreeNodes are being created.
Cursor.Current = new Cursor("MyWait.cur");
// Suppress repainting the TreeView until all the objects have been created.
treeView1.BeginUpdate();
// Clear the TreeView each time the method is called.
treeView1.Nodes.Clear();
// Add a root TreeNode for each Customer object in the ArrayList.
foreach(Customer customer2 in customerArray)
{
treeView1.Nodes.Add(new TreeNode(customer2.CustomerName));
// Add a child treenode for each Order object in the current Customer object.
foreach(Order order1 in customer2.CustomerOrders)
{
treeView1.Nodes[customerArray.IndexOf(customer2)].Nodes.Add(
new TreeNode(customer2.CustomerName + "." + order1.OrderID));
}
}
// Reset the cursor to the default for all controls.
Cursor.Current = Cursors.Default;
// Begin repainting the TreeView.
treeView1.EndUpdate();
}
Public Class Customer
Inherits [Object]
Private custName As String = ""
Friend custOrders As New ArrayList()
Public Sub New(ByVal customername As String)
Me.custName = customername
End Sub
Public Property CustomerName() As String
Get
Return Me.custName
End Get
Set(ByVal Value As String)
Me.custName = Value
End Set
End Property
Public ReadOnly Property CustomerOrders() As ArrayList
Get
Return Me.custOrders
End Get
End Property
End Class
Public Class Order
Inherits [Object]
Private ordID As String
Public Sub New(ByVal orderid As String)
Me.ordID = orderid
End Sub
Public Property OrderID() As String
Get
Return Me.ordID
End Get
Set(ByVal Value As String)
Me.ordID = Value
End Set
End Property
End Class
' Create a new ArrayList to hold the Customer objects.
Private customerArray As New ArrayList()
Private Sub FillMyTreeView()
' Add customers to the ArrayList of Customer objects.
Dim x As Integer
For x = 0 To 999
customerArray.Add(New Customer("Customer" + x.ToString()))
Next x
' Add orders to each Customer object in the ArrayList.
Dim customer1 As Customer
For Each customer1 In customerArray
Dim y As Integer
For y = 0 To 14
customer1.CustomerOrders.Add(New Order("Order" + y.ToString()))
Next y
Next customer1
' Display a wait cursor while the TreeNodes are being created.
Cursor.Current = New Cursor("MyWait.cur")
' Suppress repainting the TreeView until all the objects have been created.
treeView1.BeginUpdate()
' Clear the TreeView each time the method is called.
treeView1.Nodes.Clear()
' Add a root TreeNode for each Customer object in the ArrayList.
Dim customer2 As Customer
For Each customer2 In customerArray
treeView1.Nodes.Add(New TreeNode(customer2.CustomerName))
' Add a child TreeNode for each Order object in the current Customer object.
Dim order1 As Order
For Each order1 In customer2.CustomerOrders
treeView1.Nodes(customerArray.IndexOf(customer2)).Nodes.Add( _
New TreeNode(customer2.CustomerName + "." + order1.OrderID))
Next order1
Next customer2
' Reset the cursor to the default for all controls.
Cursor.Current = System.Windows.Forms.Cursors.Default
' Begin repainting the TreeView.
treeView1.EndUpdate()
End Sub
Remarks
The Add, Remove, and RemoveAt methods enable you to add and remove individual tree nodes from the collection.
Note
Enumerating the collection and removing nodes is not supported.
You can also use the AddRange or Clear methods to add or remove all the tree nodes from the collection.
Classes cannot inherit from the TreeNodeCollection class.
Properties
Count |
Gets the total number of TreeNode objects in the collection. |
IsReadOnly |
Gets a value indicating whether the collection is read-only. |
Item[Int32] |
Gets or sets the TreeNode at the specified indexed location in the collection. |
Item[String] |
Gets the tree node with the specified key from the collection. |
Methods
Add(String) |
Adds a new tree node with the specified label text to the end of the current tree node collection. |
Add(String, String) |
Creates a new tree node with the specified key and text, and adds it to the collection. |
Add(String, String, Int32) |
Creates a tree node with the specified key, text, and image, and adds it to the collection. |
Add(String, String, Int32, Int32) |
Creates a tree node with the specified key, text, and images, and adds it to the collection. |
Add(String, String, String) |
Creates a tree node with the specified key, text, and image, and adds it to the collection. |
Add(String, String, String, String) |
Creates a tree node with the specified key, text, and images, and adds it to the collection. |
Add(TreeNode) |
Adds a previously created tree node to the end of the tree node collection. |
AddRange(TreeNode[]) |
Adds an array of previously created tree nodes to the collection. |
Clear() |
Removes all tree nodes from the collection. |
Contains(TreeNode) |
Determines whether the specified tree node is a member of the collection. |
ContainsKey(String) |
Determines whether the collection contains a tree node with the specified key. |
CopyTo(Array, Int32) |
Copies the entire collection into an existing array at a specified location within the array. |
Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
Find(String, Boolean) |
Finds the tree nodes with specified key, optionally searching subnodes. |
GetEnumerator() |
Returns an enumerator that can be used to iterate through the tree node collection. |
GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
GetType() |
Gets the Type of the current instance. (Inherited from Object) |
IndexOf(TreeNode) |
Returns the index of the specified tree node in the collection. |
IndexOfKey(String) |
Returns the index of the first occurrence of a tree node with the specified key. |
Insert(Int32, String) |
Creates a tree node with the specified text and inserts it at the specified index. |
Insert(Int32, String, String) |
Creates a tree node with the specified text and key, and inserts it into the collection. |
Insert(Int32, String, String, Int32) |
Creates a tree node with the specified key, text, and image, and inserts it into the collection at the specified index. |
Insert(Int32, String, String, Int32, Int32) |
Creates a tree node with the specified key, text, and images, and inserts it into the collection at the specified index. |
Insert(Int32, String, String, String) |
Creates a tree node with the specified key, text, and image, and inserts it into the collection at the specified index. |
Insert(Int32, String, String, String, String) |
Creates a tree node with the specified key, text, and images, and inserts it into the collection at the specified index. |
Insert(Int32, TreeNode) |
Inserts an existing tree node into the tree node collection at the specified location. |
MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
Remove(TreeNode) |
Removes the specified tree node from the tree node collection. |
RemoveAt(Int32) |
Removes a tree node from the tree node collection at a specified index. |
RemoveByKey(String) |
Removes the tree node with the specified key from the collection. |
ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Explicit Interface Implementations
ICollection.IsSynchronized |
Gets a value indicating whether access to the collection is synchronized (thread safe). |
ICollection.SyncRoot |
Gets an object that can be used to synchronize access to the collection. |
IList.Add(Object) |
Adds an object to the end of the tree node collection. |
IList.Contains(Object) |
Determines whether the specified tree node is a member of the collection. |
IList.IndexOf(Object) |
Returns the index of the specified tree node in the collection. |
IList.Insert(Int32, Object) |
Inserts an existing tree node in the tree node collection at the specified location. |
IList.IsFixedSize |
Gets a value indicating whether the tree node collection has a fixed size. |
IList.Item[Int32] |
Gets or sets the tree node at the specified index in the collection. |
IList.Remove(Object) |
Removes the specified tree node from the tree node collection. |
Extension Methods
Cast<TResult>(IEnumerable) |
Casts the elements of an IEnumerable to the specified type. |
OfType<TResult>(IEnumerable) |
Filters the elements of an IEnumerable based on a specified type. |
AsParallel(IEnumerable) |
Enables parallelization of a query. |
AsQueryable(IEnumerable) |
Converts an IEnumerable to an IQueryable. |
Applies to
See also
.NET