ToolboxItemFilterAttribute Class

Definition

Namespace:

System.ComponentModel

Assembly:

System.ComponentModel.TypeConverter.dll

Source:

ToolboxItemFilterAttribute.cs

Specifies the filter string and filter type to use for a toolbox item.

public ref class ToolboxItemFilterAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)]
public sealed class ToolboxItemFilterAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)>]
type ToolboxItemFilterAttribute = class
    inherit Attribute

Public NotInheritable Class ToolboxItemFilterAttribute
Inherits Attribute

Inheritance

Object

Attribute

ToolboxItemFilterAttribute

Attributes

AttributeUsageAttribute

Examples

The following code example demonstrates how to apply the ToolboxItemFilterAttribute.

#using <System.Drawing.dll>
#using <System.dll>
#using <System.Design.dll>
#using <System.Windows.Forms.dll>

using namespace System;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Diagnostics;
using namespace System::Drawing;
using namespace System::Drawing::Design;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::Design;

// This example contains an IRootDesigner that implements the IToolboxUser interface.
// This example demonstrates how to enable the GetToolSupported method of an IToolboxUser
// designer in order to disable specific toolbox items, and how to respond to the 
// invocation of a ToolboxItem in the ToolPicked method of an IToolboxUser implementation.
public ref class SampleRootDesigner;

// The following attribute associates the SampleRootDesigner with this example component.

[DesignerAttribute(__typeof(SampleRootDesigner),__typeof(IRootDesigner))]
public ref class RootDesignedComponent: public Control{};


// This example component class demonstrates the associated IRootDesigner which 
// implements the IToolboxUser interface. When designer view is invoked, Visual 
// Studio .NET attempts to display a design mode view for the class at the top 
// of a code file. This can sometimes fail when the class is one of multiple types 
// in a code file, and has a DesignerAttribute associating it with an IRootDesigner. 
// Placing a derived class at the top of the code file solves this problem. A 
// derived class is not typically needed for this reason, except that placing the 
// RootDesignedComponent class in another file is not a simple solution for a code 
// example that is packaged in one segment of code.
public ref class RootViewSampleComponent: public RootDesignedComponent{};


// This example IRootDesigner implements the IToolboxUser interface and provides a 
// Windows Forms view technology view for its associated component using an internal 
// Control type.     
// The following ToolboxItemFilterAttribute enables the GetToolSupported method of this
// IToolboxUser designer to be queried to check for whether to enable or disable all 
// ToolboxItems which create any components whose type name begins with "System.Windows.Forms".

[ToolboxItemFilterAttribute(S"System.Windows.Forms",ToolboxItemFilterType::Custom)]
public ref class SampleRootDesigner: public ParentControlDesigner, public IRootDesigner, public IToolboxUser
{
public private:
   ref class RootDesignerView;

private:

   // This field is a custom Control type named RootDesignerView. This field references
   // a control that is shown in the design mode document window.
   RootDesignerView^ view;

   // This string array contains type names of components that should not be added to 
   // the component managed by this designer from the Toolbox.  Any ToolboxItems whose 
   // type name matches a type name in this array will be marked disabled according to  
   // the signal returned by the IToolboxUser.GetToolSupported method of this designer.
   array<String^>^blockedTypeNames;

public:
   SampleRootDesigner()
   {
      array<String^>^tempTypeNames = {"System.Windows.Forms.ListBox","System.Windows.Forms.GroupBox"};
      blockedTypeNames = tempTypeNames;
   }


private:

   property array<ViewTechnology>^ SupportedTechnologies 
   {

      // IRootDesigner.SupportedTechnologies is a required override for an IRootDesigner.
      // This designer provides a display using the Windows Forms view technology.
      array<ViewTechnology>^ IRootDesigner::get()
      {
         ViewTechnology temp0[] = {ViewTechnology::WindowsForms};
         return temp0;
      }

   }

   // This method returns an object that provides the view for this root designer. 
   Object^ IRootDesigner::GetView( ViewTechnology technology )
   {
      
      // If the design environment requests a view technology other than Windows 
      // Forms, this method throws an Argument Exception.
      if ( technology != ViewTechnology::WindowsForms )
            throw gcnew ArgumentException( "An unsupported view technology was requested","Unsupported view technology." );

      
      // Creates the view object if it has not yet been initialized.
      if ( view == nullptr )
            view = gcnew RootDesignerView( this );

      return view;
   }


   // This method can signal whether to enable or disable the specified
   // ToolboxItem when the component associated with this designer is selected.
   bool IToolboxUser::GetToolSupported( ToolboxItem^ tool )
   {
      
      // Search the blocked type names array for the type name of the tool
      // for which support for is being tested. Return false to indicate the
      // tool should be disabled when the associated component is selected.
      for ( int i = 0; i < blockedTypeNames->Length; i++ )
         if ( tool->TypeName == blockedTypeNames[ i ] )
                  return false;

      
      // Return true to indicate support for the tool, if the type name of the
      // tool is not located in the blockedTypeNames string array.
      return true;
   }


   // This method can perform behavior when the specified tool has been invoked.
   // Invocation of a ToolboxItem typically creates a component or components, 
   // and adds any created components to the associated component.
   void IToolboxUser::ToolPicked( ToolboxItem^ /*tool*/ ){}


public private:

   // This control provides a Windows Forms view technology view object that 
   // provides a display for the SampleRootDesigner.

   [DesignerAttribute(__typeof(ParentControlDesigner),__typeof(IDesigner))]
   ref class RootDesignerView: public Control
   {
   private:

      // This field stores a reference to a designer.
      IDesigner^ m_designer;

   public:
      RootDesignerView( IDesigner^ designer )
      {
         
         // Perform basic control initialization.
         m_designer = designer;
         BackColor = Color::Blue;
         Font = gcnew System::Drawing::Font( Font->FontFamily->Name,24.0f );
      }


   protected:

      // This method is called to draw the view for the SampleRootDesigner.
      void OnPaint( PaintEventArgs^ pe )
      {
         Control::OnPaint( pe );
         
         // Draw the name of the component in large letters.
         pe->Graphics->DrawString( m_designer->Component->Site->Name, Font, Brushes::Yellow, ClientRectangle );
      }

   };


};

using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;

// This example contains an IRootDesigner that implements the IToolboxUser interface.
// This example demonstrates how to enable the GetToolSupported method of an IToolboxUser
// designer in order to disable specific toolbox items, and how to respond to the 
// invocation of a ToolboxItem in the ToolPicked method of an IToolboxUser implementation.
namespace IToolboxUserExample
{
    // This example component class demonstrates the associated IRootDesigner which 
    // implements the IToolboxUser interface. When designer view is invoked, Visual 
    // Studio .NET attempts to display a design mode view for the class at the top 
    // of a code file. This can sometimes fail when the class is one of multiple types 
    // in a code file, and has a DesignerAttribute associating it with an IRootDesigner. 
    // Placing a derived class at the top of the code file solves this problem. A 
    // derived class is not typically needed for this reason, except that placing the 
    // RootDesignedComponent class in another file is not a simple solution for a code 
    // example that is packaged in one segment of code.
    public class RootViewSampleComponent : RootDesignedComponent
    {
    }

    // The following attribute associates the SampleRootDesigner with this example component.
    [DesignerAttribute(typeof(SampleRootDesigner), typeof(IRootDesigner))]
    public class RootDesignedComponent : System.Windows.Forms.Control
    {
    }

    // This example IRootDesigner implements the IToolboxUser interface and provides a 
    // Windows Forms view technology view for its associated component using an internal 
    // Control type.     
    // The following ToolboxItemFilterAttribute enables the GetToolSupported method of this
    // IToolboxUser designer to be queried to check for whether to enable or disable all 
    // ToolboxItems which create any components whose type name begins with "System.Windows.Forms".
    [ToolboxItemFilterAttribute("System.Windows.Forms", ToolboxItemFilterType.Custom)]
    public class SampleRootDesigner : ParentControlDesigner, IRootDesigner, IToolboxUser
    {
        // This field is a custom Control type named RootDesignerView. This field references
        // a control that is shown in the design mode document window.
        private RootDesignerView view;

        // This string array contains type names of components that should not be added to 
        // the component managed by this designer from the Toolbox.  Any ToolboxItems whose 
        // type name matches a type name in this array will be marked disabled according to  
        // the signal returned by the IToolboxUser.GetToolSupported method of this designer.
        private string[] blockedTypeNames =
        {
            "System.Windows.Forms.ListBox",
            "System.Windows.Forms.GroupBox"
        };

        // IRootDesigner.SupportedTechnologies is a required override for an IRootDesigner.
        // This designer provides a display using the Windows Forms view technology.
        ViewTechnology[] IRootDesigner.SupportedTechnologies 
        {
            get { return new ViewTechnology[] {ViewTechnology.Default}; }
        }

        // This method returns an object that provides the view for this root designer. 
        object IRootDesigner.GetView(ViewTechnology technology) 
        {
            // If the design environment requests a view technology other than Windows 
            // Forms, this method throws an Argument Exception.
            if (technology != ViewTechnology.Default)            
                throw new ArgumentException("An unsupported view technology was requested", 
                "Unsupported view technology.");            
            
            // Creates the view object if it has not yet been initialized.
            if (view == null)                            
                view = new RootDesignerView(this);          
  
            return view;
        }

        // This method can signal whether to enable or disable the specified
        // ToolboxItem when the component associated with this designer is selected.
        bool IToolboxUser.GetToolSupported(ToolboxItem tool)
        {       
            // Search the blocked type names array for the type name of the tool
            // for which support for is being tested. Return false to indicate the
            // tool should be disabled when the associated component is selected.
            for( int i=0; i<blockedTypeNames.Length; i++ )
                if( tool.TypeName == blockedTypeNames[i] )
                    return false;
            
            // Return true to indicate support for the tool, if the type name of the
            // tool is not located in the blockedTypeNames string array.
            return true;
        }
    
        // This method can perform behavior when the specified tool has been invoked.
        // Invocation of a ToolboxItem typically creates a component or components, 
        // and adds any created components to the associated component.
        void IToolboxUser.ToolPicked(ToolboxItem tool)
        {
        }

        // This control provides a Windows Forms view technology view object that 
        // provides a display for the SampleRootDesigner.
        [DesignerAttribute(typeof(ParentControlDesigner), typeof(IDesigner))]
        internal class RootDesignerView : Control
        {
            // This field stores a reference to a designer.
            private IDesigner m_designer;

            public RootDesignerView(IDesigner designer)
            {
                // Perform basic control initialization.
                m_designer = designer;
                BackColor = Color.Blue;
                Font = new Font(Font.FontFamily.Name, 24.0f);                
            }

            // This method is called to draw the view for the SampleRootDesigner.
            protected override void OnPaint(PaintEventArgs pe)
            {
                base.OnPaint(pe);
                // Draw the name of the component in large letters.
                pe.Graphics.DrawString(m_designer.Component.Site.Name, Font, Brushes.Yellow, ClientRectangle);
            }
        }
    }
}

Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Diagnostics
Imports System.Drawing
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Windows.Forms.Design

' This example contains an IRootDesigner that implements the IToolboxUser interface.
' This example demonstrates how to enable the GetToolSupported method of an IToolboxUser
' designer in order to disable specific toolbox items, and how to respond to the 
' invocation of a ToolboxItem in the ToolPicked method of an IToolboxUser implementation.
' This example component class demonstrates the associated IRootDesigner which 
' implements the IToolboxUser interface. When designer view is invoked, Visual 
' Studio .NET attempts to display a design mode view for the class at the top 
' of a code file. This can sometimes fail when the class is one of multiple types 
' in a code file, and has a DesignerAttribute associating it with an IRootDesigner. 
' Placing a derived class at the top of the code file solves this problem. A 
' derived class is not typically needed for this reason, except that placing the 
' RootDesignedComponent class in another file is not a simple solution for a code 
' example that is packaged in one segment of code.

Public Class RootViewSampleComponent
    Inherits RootDesignedComponent
End Class

' The following attribute associates the SampleRootDesigner with this example component.
<DesignerAttribute(GetType(SampleRootDesigner), GetType(IRootDesigner))> _
Public Class RootDesignedComponent
    Inherits System.Windows.Forms.Control
End Class

' This example IRootDesigner implements the IToolboxUser interface and provides a 
' Windows Forms view technology view for its associated component using an internal 
' Control type.     
' The following ToolboxItemFilterAttribute enables the GetToolSupported method of this
' IToolboxUser designer to be queried to check for whether to enable or disable all 
' ToolboxItems which create any components whose type name begins with "System.Windows.Forms".
<ToolboxItemFilterAttribute("System.Windows.Forms", ToolboxItemFilterType.Custom)> _
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Public Class SampleRootDesigner
    Inherits ParentControlDesigner
    Implements IRootDesigner, IToolboxUser

    ' Member field of custom type RootDesignerView, a control that is shown in the 
    ' design mode document window. This member is cached to reduce processing needed 
    ' to recreate the view control on each call to GetView().
    Private m_view As RootDesignerView

    ' This string array contains type names of components that should not be added to 
    ' the component managed by this designer from the Toolbox.  Any ToolboxItems whose 
    ' type name matches a type name in this array will be marked disabled according to  
    ' the signal returned by the IToolboxUser.GetToolSupported method of this designer.
    Private blockedTypeNames As String() = {"System.Windows.Forms.ListBox", "System.Windows.Forms.GroupBox"}

    ' IRootDesigner.SupportedTechnologies is a required override for an IRootDesigner.
    ' This designer provides a display using the Windows Forms view technology.
    ReadOnly Property SupportedTechnologies() As ViewTechnology() Implements IRootDesigner.SupportedTechnologies
        Get
            Return New ViewTechnology() {ViewTechnology.Default}
        End Get
    End Property

    ' This method returns an object that provides the view for this root designer. 
    Function GetView(ByVal technology As ViewTechnology) As Object Implements IRootDesigner.GetView
        ' If the design environment requests a view technology other than Windows 
        ' Forms, this method throws an Argument Exception.
        If technology <> ViewTechnology.Default Then
            Throw New ArgumentException("An unsupported view technology was requested", "Unsupported view technology.")
        End If

        ' Creates the view object if it has not yet been initialized.
        If m_view Is Nothing Then
            m_view = New RootDesignerView(Me)
        End If
        Return m_view
    End Function

    ' This method can signal whether to enable or disable the specified
    ' ToolboxItem when the component associated with this designer is selected.
    Function GetToolSupported(ByVal tool As ToolboxItem) As Boolean Implements IToolboxUser.GetToolSupported
        ' Search the blocked type names array for the type name of the tool
        ' for which support for is being tested. Return false to indicate the
        ' tool should be disabled when the associated component is selected.
        Dim i As Integer
        For i = 0 To blockedTypeNames.Length - 1
            If tool.TypeName = blockedTypeNames(i) Then
                Return False
            End If
        Next i ' Return true to indicate support for the tool, if the type name of the
        ' tool is not located in the blockedTypeNames string array.
        Return True
    End Function

    ' This method can perform behavior when the specified tool has been invoked.
    ' Invocation of a ToolboxItem typically creates a component or components, 
    ' and adds any created components to the associated component.
    Sub ToolPicked(ByVal tool As ToolboxItem) Implements IToolboxUser.ToolPicked
    End Sub

    ' This control provides a Windows Forms view technology view object that 
    ' provides a display for the SampleRootDesigner.
    <DesignerAttribute(GetType(ParentControlDesigner), GetType(IDesigner))> _
    Friend Class RootDesignerView
        Inherits Control
        ' This field stores a reference to a designer.
        Private m_designer As IDesigner

        Public Sub New(ByVal designer As IDesigner)
            ' Performs basic control initialization.
            m_designer = designer
            BackColor = Color.Blue
            Font = New Font(Font.FontFamily.Name, 24.0F)
        End Sub

        ' This method is called to draw the view for the SampleRootDesigner.
        Protected Overrides Sub OnPaint(ByVal pe As PaintEventArgs)
            MyBase.OnPaint(pe)
            ' Draws the name of the component in large letters.
            pe.Graphics.DrawString(m_designer.Component.Site.Name, Font, Brushes.Yellow, New RectangleF(ClientRectangle.X, ClientRectangle.Y, ClientRectangle.Width, ClientRectangle.Height))
        End Sub
    End Class
End Class

Remarks

ToolboxItemFilterAttribute provides a mechanism by which toolbox items can be marked for use only with designers that have a matching attribute or code that determines whether the item should be enabled or disabled in the toolbox.

A ToolboxItemFilterAttribute can be applied to a ToolboxItem to indicate a filter string and filter type that specify when to enable or disable the item. ToolboxItemFilterAttribute can also be applied to a designer to indicate its requirements for enabling items in the toolbox. This type of attribute can be used to indicate that a toolbox item can only be enabled when a designer with a matching filter string is being used. The type of the filter is indicated in the FilterType property by a ToolboxItemFilterType that indicates whether and how a filter string match is used, or whether to use custom code to determine whether to enable an item.

Constructors

ToolboxItemFilterAttribute(String)	Initializes a new instance of the ToolboxItemFilterAttribute class using the specified filter string.
ToolboxItemFilterAttribute(String, ToolboxItemFilterType)	Initializes a new instance of the ToolboxItemFilterAttribute class using the specified filter string and type.

Properties

FilterString	Gets the filter string for the toolbox item.
FilterType	Gets the type of the filter.
TypeId	Gets the type ID for the attribute.

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object.
GetHashCode()	Returns the hash code for this instance.
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	Indicates whether the specified object has a matching filter string.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object.

See also

• ToolboxItemFilterType