ViewCollection Class

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

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 container that enables a MultiView control to maintain a list of its child controls.

public ref class ViewCollection : System::Web::UI::ControlCollection

public class ViewCollection : System.Web.UI.ControlCollection

type ViewCollection = class
    inherit ControlCollection

Public Class ViewCollection
Inherits ControlCollection

Inheritance: Object

ControlCollection
ViewCollection

Examples

The following code example demonstrates how to programmatically add View controls to a MultiView control. After each View control is created, the AddAt method is used to add the View control to the ViewCollection collection of the MultiView control at the specified index. The Item[] indexer is used to access the ID properties of the View controls stored in the ViewCollection collection and display them to the user.

<%@ Page Language="VB"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>ViewCollection example</title>
<script runat="server">
      
        Sub Button1_Click(ByVal Sender As Object, ByVal e As EventArgs)
            ' Create a MultiView control.
            Dim MultiView1 As New MultiView

            ' Create a ViewCollection for the View 
            ' controls contained in MultiView1.
            Dim myViewCollection As New ViewCollection(MultiView1)

            ' Create a View control. 
            Dim View1 As New View
            ' Use a helper function to create the view.
            View1 = CreateView("View1")
            ' Add View1 to myViewCollection at index 0.
            myViewCollection.AddAt(0, View1)

            ' Create a second View control and 
            ' add it to myViewCollection at index 1.
            Dim View2 As New View
            View2 = CreateView("View2")
            myViewCollection.AddAt(1, View2)

            ' Create a third View control and 
            ' add it to myViewCollection at index 0.
            ' Inserting View3 at index 0 
            ' causes View1 to move to index 1  
            ' and View2 to move to index 2.
            Dim View3 As New View
            View3 = CreateView("View3")
            myViewCollection.AddAt(0, View3)

            ' Show the contents of myViewCollection on the page.
            DisplayViewCollectionContents(myViewCollection)
            
        End Sub

        ' A function to programmatically create a View control.
        Private Function CreateView(ByVal viewId As String) As View
            ' Create a View control
            Dim myView As New View
            myView.ID = viewId

            ' Create a Panel control.
            Dim Panel1 As New Panel

            ' Set the style properties for Panel1.
            Panel1.Height = New Unit(150)
            Panel1.Width = New Unit(150)
            Panel1.BackColor = System.Drawing.Color.Azure
            Panel1.BorderStyle = BorderStyle.Double

            ' Add Panel1 to the Controls collection
            ' of the View control.
            myView.Controls.Add(Panel1)

            ' Create a Label control.
            Dim Label1 As New Label

            ' Set the properties for Label1.
            Label1.Text = "This is " + CStr(myView.ID)

            ' Add Label1 to the Controls collection
            ' of the Panel1 control.
            Panel1.Controls.Add(Label1)

            Return myView
        End Function

        ' A sub-routine to display the contents of myViewCollection.
        Sub DisplayViewCollectionContents(ByVal collection As ViewCollection)
            ' Use the Item property to access the ID of the View
            ' control at the specified index in the collection.
            Label1.Text = "The view at index 0 is " + collection.Item(0).ID
            Label2.Text = "The view at index 1 is " + collection.Item(1).ID
            Label3.Text = "The view at index 2 is " + collection.Item(2).ID
        End Sub

</script>
 
</head>
<body>

    <form id="Form1" runat="server">

        <h3>ViewCollection example</h3> 

        <asp:Button id="Button2" 
            Text="Show ViewCollection contents" 
            OnClick="Button1_Click" 
            runat="Server"/>
        <br /><br />  
        
        <hr />
  
        <asp:Label ID="Label1"
            runat="Server">
        </asp:Label><br /><br /> 

        <asp:Label ID="Label2"
            runat="Server">
        </asp:Label><br /><br />

        <asp:Label ID="Label3"
            runat="Server">
        </asp:Label><br /><br /> 
       
    </form>
   
</body>
</html>

Remarks

The ViewCollection class represents a collection container that enables a MultiView control to maintain a list of its child controls. A MultiView control can contain only View controls as child controls.

Use the Add method to add a new View control to the ViewCollection collection at the end of an ordinal index array. Use the AddAt method to add a new control at a specific index location. Use the Item[] indexer to get a View control from the ViewCollection collection at a specified index, using simple array notation.

Constructors

ViewCollection(Control)

Initializes a new instance of the ViewCollection 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 View control at the specified index location in the ViewCollection collection.
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)	Adds the specified View control to the collection.
AddAt(Int32, Control)	Adds the specified View control to the collection at the specified index location.
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

Udostępnij za pośrednictwem