EmptyControlCollection Class

Definition

Provides standard support for a ControlCollection collection that is always empty.

public ref class EmptyControlCollection : System::Web::UI::ControlCollection
public class EmptyControlCollection : System.Web.UI.ControlCollection
type EmptyControlCollection = class
    inherit ControlCollection
Public Class EmptyControlCollection
Inherits ControlCollection
Inheritance
EmptyControlCollection

Examples


/* File name: emptyControlCollection.cs. */

using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;

namespace CustomControls
{

  // Defines a simple custom control.
  public class MyCS_EmptyControl : Control
  {
    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
    protected override ControlCollection CreateControlCollection() 
    /*
     * Function Name: CreateControlCollection.
     * Denies the creation of any child control by creating an empty collection.
     * Generates an exception if an attempt to create a child control is made.
     */
     {
       return new EmptyControlCollection(this);
     }
     
     [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
     protected override void CreateChildControls()
     /*
      * Function Name: CreateChildControls.
      * Populates the child control collection (Controls). 
      * Note: This function will cause an exception because the control does not allow 
      * child controls.
      */
      {
        // Create a literal control to contain the header and add it to the collection.
        LiteralControl text;
        text = new LiteralControl("<h5>Composite Controls</h5>");
        Controls.Add(text);
      }
   }

}

' File name: emptyControlCollection.vb.

Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Collections


Namespace CustomControls 

  Public Class MyVB_EmptyControl 
    Inherits Control
    
    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Function CreateControlCollection() As ControlCollection
    ' Function Name: CreateControlCollection.
    ' Denies the creation of any child control by creating an empty collection.
    ' Generates an exception if an attempt to create a child control is made.
      Return New EmptyControlCollection(Me)
    End Function 
    
    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _  
    Protected Overrides Sub CreateChildControls()
    ' Sub Name: CreateChildControls.
    ' Populates the child control collection (Controls). 
    ' Note: This function will cause an exception because the control does not allow 
    ' child controls.
      Dim text As LiteralControl
      text = New LiteralControl("<h5>Composite Controls</h5>")
      Controls.Add(text)
    End Sub 
  End Class 

End Namespace 

Remarks

This class is used when you want to define a custom control that does not allow child controls.

Constructors

EmptyControlCollection(Control)

Initializes a new instance of the EmptyControlCollection class.

Properties

Count

Gets the number of server controls in the ControlCollection object for the specified ASP.NET server control.

(Inherited from ControlCollection)
IsReadOnly

Gets a value indicating whether the ControlCollection object is read-only.

(Inherited from ControlCollection)
IsSynchronized

Gets a value indicating whether the ControlCollection object is synchronized.

(Inherited from ControlCollection)
Item[Int32]

Gets a reference to the server control at the specified index location in the ControlCollection object.

(Inherited from ControlCollection)
Owner

Gets the ASP.NET server control to which the ControlCollection object belongs.

(Inherited from ControlCollection)
SyncRoot

Gets an object that can be used to synchronize access to the collection of controls.

(Inherited from ControlCollection)

Methods

Add(Control)

Denies the addition of the specified Control object to the collection.

AddAt(Int32, Control)

Denies the addition of the specified Control object to the collection, at the specified index position.

Clear()

Removes all controls from the current server control's ControlCollection object.

(Inherited from ControlCollection)
Contains(Control)

Determines whether the specified server control is in the parent server control's ControlCollection object.

(Inherited from ControlCollection)
CopyTo(Array, Int32)

Copies the child controls stored in the ControlCollection object to an Array object, beginning at the specified index location in the Array.

(Inherited from ControlCollection)
Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetEnumerator()

Retrieves an enumerator that can iterate through the ControlCollection object.

(Inherited from ControlCollection)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
IndexOf(Control)

Retrieves the index of a specified Control object in the collection.

(Inherited from ControlCollection)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
Remove(Control)

Removes the specified server control from the parent server control's ControlCollection object.

(Inherited from ControlCollection)
RemoveAt(Int32)

Removes a child control, at the specified index location, from the ControlCollection object.

(Inherited from ControlCollection)
ToString()

Returns a string that represents the current object.

(Inherited from Object)

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