ToolboxItemFilterType Enumeration

 
System_CAPS_noteNote

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Defines identifiers used to indicate the type of filter that a ToolboxItemFilterAttribute uses.

Namespace:   System.ComponentModel
Assembly:  System (in System.dll)

public enum class ToolboxItemFilterType

Member nameDescription
Allow

Indicates that a toolbox item filter string is allowed, but not required.

Custom

Indicates that custom processing is required to determine whether to use a toolbox item filter string.

Prevent

Indicates that a toolbox item filter string is not allowed.

Require

Indicates that a toolbox item filter string must be present for a toolbox item to be enabled.

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 );
      }

   };


};

.NET Framework
Available since 1.1
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