ControlPersister Class

 

Provides methods for persisting Web server controls at design-time.

Namespace:   System.Web.UI.Design
Assembly:  System.Design (in System.Design.dll)

System.Object
  System.Web.UI.Design.ControlPersister

<SecurityPermissionAttribute(SecurityAction.Demand, Flags := SecurityPermissionFlag.UnmanagedCode)>
Public NotInheritable Class ControlPersister

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodSystem_CAPS_staticPersistControl(Control)

Gets a string of data that represents the persisted form of the specified control.

System_CAPS_pubmethodSystem_CAPS_staticPersistControl(Control, IDesignerHost)

Gets a string of data that represents the persisted form of the specified control, using the specified designer host.

System_CAPS_pubmethodSystem_CAPS_staticPersistControl(TextWriter, Control)

Outputs a string of data that represents the persisted form of the specified control to the specified TextWriter.

System_CAPS_pubmethodSystem_CAPS_staticPersistControl(TextWriter, Control, IDesignerHost)

Outputs a string of data that represents the persisted form of the specified control to the specified TextWriter, using the specified designer host.

System_CAPS_pubmethodSystem_CAPS_staticPersistInnerProperties(Object, IDesignerHost)

Gets a string of data that can persist the inner properties of the specified control.

System_CAPS_pubmethodSystem_CAPS_staticPersistInnerProperties(TextWriter, Object, IDesignerHost)

Outputs a string of data that can persist the inner properties of the specified control to the specified TextWriter, using the specified designer host.

System_CAPS_pubmethodSystem_CAPS_staticPersistTemplate(ITemplate, IDesignerHost)

Gets a string of data that represents the persisted form of the specified template.

System_CAPS_pubmethodSystem_CAPS_staticPersistTemplate(TextWriter, ITemplate, IDesignerHost)

Writes a string of data that represents the persisted form of the specified template to the specified TextWriter object.

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

The ControlPersister class provides methods that can persist a Control control or an ITemplate interface implementation as a string of aspx code. The implementation of these methods is driven by metadata attributes, such as the DefaultValueAttribute, PersistenceModeAttribute, and DesignerSerializationVisibilityAttribute.

System_CAPS_noteNote

The Web Forms page designer does not support the ResetPropertyName method that is optionally exposed by Microsoft Windows Forms-based controls for property persistence.

To create a Control object or an ITemplate interface by parsing a string of control- or template-persistence data, use the ControlParser class methods.

Imports Microsoft.VisualBasic
Imports System
Imports System.Drawing
Imports System.Drawing.Design
Imports System.Web.UI
Imports System.Web.UI.Design
Imports System.Web.UI.WebControls
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Windows.Forms
Imports System.Windows.Forms.Design

Namespace ControlParserPersisterDesignerControl_VB

    ' Web control designer provides an interface 
    '   to use the ControlPersister and ControlParser.
    ' The DesignerActionListCollection must run under "FullTrust",
    '   so you must also require your designer to run under "FullTrust".
    <System.Security.Permissions.PermissionSetAttribute( _
        System.Security.Permissions.SecurityAction.InheritanceDemand, _
        Name:="FullTrust")> _
    <System.Security.Permissions.PermissionSetAttribute( _
         Security.Permissions.SecurityAction.Demand, _
         Name:="FullTrust")> _
    Public Class ControlParserPersisterDesigner
        Inherits System.Web.UI.Design.ControlDesigner

        Private _actLists As DesignerActionListCollection

        Public Sub New()
        End Sub

        ' Creates designer menu commands to persist 
        ' a control and to load a persisted control.
        Public Overrides ReadOnly Property ActionLists() As System.ComponentModel.Design.DesignerActionListCollection
            Get
                If IsNothing(_actLists) Then
                    _actLists = New DesignerActionListCollection()
                    _actLists.AddRange(MyBase.ActionLists)
                    _actLists.Add(New ParserActionList(Me))
                End If

                Return _actLists
            End Get
        End Property
        'Public Overrides ReadOnly Property Verbs() _
        'As System.ComponentModel.Design.DesignerVerbCollection
        '    Get
        '        Dim dvc As New DesignerVerbCollection()
        '        dvc.Add(New DesignerVerb("Load Persisted Control...", _
        '            New EventHandler(AddressOf Me.loadPersistedControl)))
        '        dvc.Add(New DesignerVerb("Parse and Save Control...", _
        '            New EventHandler(AddressOf Me.saveControl)))
        '        Return dvc
        '    End Get
        'End Property

        ' Displays a textbox form to receive an HTML 
        ' string that represents a control, and creates
        ' a toolbox item for the control, if not already
        ' present in the selected toolbox category.

        Private Class ParserActionList
            Inherits DesignerActionList

            Private _parent As ControlParserPersisterDesigner
            Private _items As DesignerActionItemCollection

            Public Sub New(ByVal parent As ControlParserPersisterDesigner)
                MyBase.New(parent.Component)
                _parent = parent
            End Sub

            Public Overrides Function GetSortedActionItems() As System.ComponentModel.Design.DesignerActionItemCollection
                If IsNothing(_items) Then
                    _items = New DesignerActionItemCollection()
                    _items.Add(New DesignerActionMethodItem(Me, "saveControl", "Parse and Save Control...", True))
                    _items.Add(New DesignerActionMethodItem(Me, "loadPersistedControl", "Load Persisted Control...", True))
                End If
                Return _items
            End Function

            ' Displays a list of controls in the project, if any,
            ' and displays the HTML markup for the selected control.       
            Private Sub saveControl()
                ' Get the collection of components in the current 
                ' design mode document.
                Dim documentComponents As ComponentCollection = _
                    Me.Component.Site.Container.Components

                ' Filter the components to those that derive from the 
                ' System.Web.UI.Control class.

                ' Create an IComponent array of the maximum possible length needed.
                Dim filterArray(documentComponents.Count) As IComponent

                ' Count the total qualifying components.
                Dim total As Integer = 0
                Dim i As Integer
                For i = 0 To documentComponents.Count - 1
                    ' If the component derives from System.Web.UI.Control, 
                    ' copy a reference to the control to the filterArray 
                    ' array and increment the control count.
                    If GetType(System.Web.UI.Control).IsAssignableFrom(CType(documentComponents(i), Object).GetType()) Then
                        If Not (CType(documentComponents(i), System.Web.UI.Control).UniqueID Is Nothing) Then
                            filterArray(total) = documentComponents(i)
                            total += 1
                        End If
                    End If
                Next i

                If total = 0 Then
                    Throw New Exception( _
                        "Document contains no System.Web.UI.Control components.")
                End If

                ' Move the components that derive from System.Web.UI.Control to a 
                ' new array of the correct size.
                Dim controlArray(total - 1) As System.Web.UI.Control

                For i = 0 To total - 1
                    controlArray(i) = CType(filterArray(i), System.Web.UI.Control)
                Next i

                ' Create a ControlSelectionForm to provide a persistence 
                ' configuration interface.
                Dim selectionForm As New ControlSelectionForm(controlArray)

                ' Display the form.
                If selectionForm.ShowDialog() <> DialogResult.OK Then
                    Return
                End If

                ' Validate the selection.
                If selectionForm.controlList.SelectedIndex = -1 Then
                    Throw New Exception("You must select a control to persist.")
                End If

                ' Parse the selected control.
                Dim persistedData As String = ControlPersister.PersistControl( _
                    controlArray(selectionForm.controlList.SelectedIndex))

                ' Display the control persistence string in a text box.
                Dim displayForm As New StringDisplayForm(persistedData)
                displayForm.ShowDialog()
            End Sub

            ' Displays a textbox form to receive an HTML 
            ' string that represents a control, and creates
            ' a toolbox item for the control, if not already
            ' present in the selected toolbox category.
            Private Sub loadPersistedControl()
                ' Display a StringInputForm to obtain a persisted control string.
                Dim inputForm As New StringInputForm()

                If inputForm.ShowDialog() <> DialogResult.OK Then
                    Return
                End If
                If inputForm.TxBox.Text.Length < 2 Then
                    Return
                End If
                ' Obtain an IDesignerHost for the design-mode document.
                Dim host As IDesignerHost = CType(Me.Component.Site.GetService(GetType(IDesignerHost)), IDesignerHost)

                ' Create a Web control from the persisted control string.
                Dim ctrl As System.Web.UI.Control = ControlParser.ParseControl(host, inputForm.TxBox.Text.Trim())

                ' Create a Web control toolbox item for the type of the control.
                Dim item As New System.Web.UI.Design.WebControlToolboxItem(ctrl.GetType())

                ' Add the Web control toolbox item to the toolbox.
                Dim toolService As IToolboxService = CType(Me.Component.Site.GetService(GetType(IToolboxService)), IToolboxService)
                If Not (toolService Is Nothing) Then
                    toolService.AddToolboxItem(item)
                Else
                    Throw New Exception("IToolboxService was not found.")
                End If
            End Sub
        End Class
    End Class

    ' Simple text display control hosts the ControlParserPersisterDesigner.
    <DesignerAttribute(GetType(ControlParserPersisterDesigner), _
        GetType(IDesigner))> _
    Public Class ControlParserPersisterDesignerControl
        Inherits System.Web.UI.WebControls.WebControl

        Private _text As String

        <Bindable(True), _
            Category("Appearance"), _
            DefaultValue("")> _
        Public Property [Text]() As String
            Get
                Return _text
            End Get
            Set(ByVal Value As String)
                _text = Value
            End Set
        End Property

        Public Sub New()
            [Text] = "Right-click here to access control persistence " & _
                        "methods in design mode"
        End Sub

        Protected Overrides Sub Render(ByVal output As HtmlTextWriter)
            output.Write([Text])
        End Sub
    End Class

    ' Provides a form with a list for selection.
    Friend Class ControlSelectionForm
        Inherits System.Windows.Forms.Form
        Private controlArray() As System.Web.UI.Control
        Public controlList As System.Windows.Forms.ListBox

        Public Sub New(ByVal controlArray() As System.Web.UI.Control)
            Me.controlArray = controlArray

            Me.Size = New Size(400, 500)
            Me.Text = "Control Persister Selection Form"

            Me.SuspendLayout()

            Dim label1 As New System.Windows.Forms.Label()
            label1.Text = "Select the control to persist:"
            label1.Size = New Size(240, 20)
            label1.Location = New Point(10, 10)
            Me.Controls.Add(label1)

            controlList = New System.Windows.Forms.ListBox()
            controlList.Size = New Size(370, 400)
            controlList.Location = New Point(10, 30)
            controlList.Anchor = AnchorStyles.Left Or AnchorStyles.Top _
                    Or AnchorStyles.Bottom Or AnchorStyles.Right
            Me.Controls.Add(controlList)

            Dim okButton As New System.Windows.Forms.Button()
            okButton.Text = "OK"
            okButton.Size = New Size(80, 24)
            okButton.Location = New Point(Me.Width - 100, Me.Height - 60)
            okButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            okButton.DialogResult = DialogResult.OK
            Me.Controls.Add(okButton)

            Dim cancelButton As New System.Windows.Forms.Button()
            cancelButton.Text = "Cancel"
            cancelButton.Size = New Size(80, 24)
            cancelButton.Location = New Point(Me.Width - 200, Me.Height - 60)
            cancelButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            cancelButton.DialogResult = DialogResult.Cancel
            Me.Controls.Add(cancelButton)

            Dim i As Integer
            For i = 0 To controlArray.Length - 1
                controlList.Items.Add(controlArray(i).UniqueID)
            Next i
            Me.ResumeLayout()
        End Sub
    End Class

    ' Provides a form with a multiline text box display.
    Friend Class StringDisplayForm
        Inherits System.Windows.Forms.Form

        Private tbox As New System.Windows.Forms.TextBox()

        Public Property TxBox() As System.Windows.Forms.TextBox
            Get
                Return tbox
            End Get
            Set(ByVal value As System.Windows.Forms.TextBox)
                tbox = value
            End Set
        End Property

        Public Sub New(ByVal displayText As String)
            Me.Size = New Size(400, 300)
            Me.Text = "Control Persistence String"

            Me.SuspendLayout()
            Dim tbox As New System.Windows.Forms.TextBox()
            tbox.Multiline = True
            tbox.Size = New Size(Me.Width - 40, Me.Height - 90)
            tbox.Text = displayText
            Me.Controls.Add(tbox)

            Dim okButton As New System.Windows.Forms.Button()
            okButton.Text = "OK"
            okButton.Size = New Size(80, 24)
            okButton.Location = New Point(Me.Width - 100, Me.Height - 60)
            okButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            okButton.DialogResult = DialogResult.OK
            Me.Controls.Add(okButton)

            Me.ResumeLayout()
        End Sub
    End Class

    ' Provides a form with a multiline text box for input.
    Friend Class StringInputForm
        Inherits System.Windows.Forms.Form
        Private tbox As New System.Windows.Forms.TextBox()

        Public Property TxBox() As System.Windows.Forms.TextBox
            Get
                Return tbox
            End Get
            Set(ByVal value As System.Windows.Forms.TextBox)
                tbox = value
            End Set
        End Property

        Public Sub New()
            Me.Size = New Size(400, 400)
            Me.Text = "Input Control Persistence String"

            Me.SuspendLayout()
            tbox = New System.Windows.Forms.TextBox()
            tbox.Multiline = True
            tbox.Size = New Size(Me.Width - 40, Me.Height - 90)
            tbox.Text = ""
            Me.Controls.Add(tbox)

            Dim okButton As New System.Windows.Forms.Button()
            okButton.Text = "OK"
            okButton.Size = New Size(80, 24)
            okButton.Location = New Point(Me.Width - 100, Me.Height - 60)
            okButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            okButton.DialogResult = DialogResult.OK
            Me.Controls.Add(okButton)

            Dim cancelButton As New System.Windows.Forms.Button()
            cancelButton.Text = "Cancel"
            cancelButton.Size = New Size(80, 24)
            cancelButton.Location = New Point(Me.Width - 200, Me.Height - 60)
            cancelButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            cancelButton.DialogResult = DialogResult.Cancel
            Me.Controls.Add(cancelButton)

            Me.ResumeLayout()
        End Sub
    End Class
End Namespace

.NET Framework
Available since 1.1

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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