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EventsTab Class

Provides a PropertyTab that can display events for selection and linking.

For a list of all members of this type, see EventsTab Members.

System.Object
   System.Windows.Forms.Design.PropertyTab
      System.Windows.Forms.Design.EventsTab

[Visual Basic]
Public Class EventsTab
   Inherits PropertyTab
[C#]
public class EventsTab : PropertyTab
[C++]
public __gc class EventsTab : public PropertyTab
[JScript]
public class EventsTab extends PropertyTab

Thread Safety

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

Example

[C#, C++] The following code example provides an example EventsTab. When selected, the EventsTab lists any events on a component in order of delegate type.

[C#] 
using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Collections;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Windows.Forms;
using System.Windows.Forms.Design;

namespace EventsTabExample
{    
    // This component adds a TypeEventsTab to the Properties Window.
    [PropertyTabAttribute(typeof(TypeEventsTab), PropertyTabScope.Document)]
    public class TypeEventsTabComponent : Component
    {
        public TypeEventsTabComponent()
        {
        }
    }

    // This example events tab lists events by their delegate type.
    public class TypeEventsTab : System.Windows.Forms.Design.EventsTab
    {
        [BrowsableAttribute(true)]
        // This string contains a Base-64 encoded and serialized example 
        // property tab image.
        private string img = "AAEAAAD/////AQAAAAAAAAAMAgAAAFRTeXN0ZW0uRHJhd2luZywgVmVyc2lvbj0xLjAuMzMwMC4wLCBDdWx0dXJlPW5ldXRyYWwsIFB1YmxpY0tleVRva2VuPWIwM2Y1ZjdmMTFkNTBhM2EFAQAAABVTeXN0ZW0uRHJhd2luZy5CaXRtYXABAAAABERhdGEHAgIAAAAJAwAAAA8DAAAAtgIAAAJCTbYCAAAAAAAANgAAACgAAAANAAAAEAAAAAEAGAAAAAAAAAAAAMQOAADEDgAAAAAAAAAAAADO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tn/ztbZztbZHh4eHh4eztbZztbZztbZztbZztbZztbZztbZztbZztbZ/87W2c7W2QDBAB4eHh4eHs7W2c7W2c7W2c7W2c7W2c7W2c7W2c7W2f/O1tnO1tnO1tkAwQAeHh4eHh7O1tnO1tnO1tnO1tnO1tnO1tnO1tn/ztbZztbZlJSU////AMEAHh4eHh4eztbZztbZztbZztbZztbZztbZ/87W2c7W2c7W2ZSUlP///wDBAB4eHh4eHs7W2c7W2c7W2c7W2c7W2f/O1tnO1tnO1tnO1tmUlJT///8AwQAeHh4eHh7O1tnO1tnO1tnO1tn/ztbZHh4eHh4eHh4eHh4eHh4e////AIAAHh4eHh4eztbZztbZztbZ/87W2ZSUlP///wDBAADBAADBAADBAADBAACAAB4eHh4eHs7W2c7W2f/O1tnO1tmUlJT///8AwQAAgAAeHh4eHh7O1tnO1tnO1tnO1tnO1tn/ztbZztbZztbZlJSU////AMEAAIAAHh4eHh4eztbZztbZztbZztbZ/87W2c7W2c7W2c7W2ZSUlP///wDBAACAAB4eHh4eHs7W2c7W2c7W2f/O1tnO1tnO1tnO1tnO1tmUlJT///8AwQAAgAAeHh4eHh7O1tnO1tn/ztbZztbZztbZztbZztbZztbZlJSU////AMEAAIAAHh4eHh4eztbZ/87W2c7W2c7W2c7W2c7W2c7W2c7W2ZSUlP///wDBAACAAB4eHs7W2f/O1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tn/Cw==";
        private IServiceProvider sp;

        public TypeEventsTab(IServiceProvider sp) : base(sp)
        {
            this.sp = sp;           
        }
                  
        // Returns the properties of the specified component extended with a 
        // CategoryAttribute reflecting the name of the type of the property.
        public override System.ComponentModel.PropertyDescriptorCollection 
            GetProperties(ITypeDescriptorContext context, object component, 
            System.Attribute[] attributes)
        {            
            // Obtain an instance of the IEventBindingService.
            IEventBindingService eventPropertySvc = (IEventBindingService)
                sp.GetService(typeof(IEventBindingService));

            // Return if an IEventBindingService could not be obtained.
            if (eventPropertySvc == null)             
                return new PropertyDescriptorCollection(null);
            
            // Obtain the events on the component.
            EventDescriptorCollection events = 
                TypeDescriptor.GetEvents(component, attributes);       
     
            // Create an array of the events, where each event is assigned 
            // a category matching its type.
            EventDescriptor[] newEvents = new EventDescriptor[events.Count];
            for(int i=0;i < events.Count;i++)             
                newEvents[i] = TypeDescriptor.CreateEvent(events[i].ComponentType, events[i], 
                    new CategoryAttribute(events[i].EventType.FullName));            
            events = new EventDescriptorCollection(newEvents);

            // Return event properties for the event descriptors.
            return eventPropertySvc.GetEventProperties(events);
        }        

        // Provides the name for the event property tab.
        public override string TabName
        {
            get
            {
                return "Events by Type";
            }
        }

        // Provides an image for the event property tab.
        public override System.Drawing.Bitmap Bitmap
        {
            get
            {
                Bitmap bmp = new Bitmap(DeserializeFromBase64Text(img));
                return bmp;
            }
        }

        // This method can be used to retrieve an Image from a block of 
        // Base64-encoded text.
        private Image DeserializeFromBase64Text(string text)
        {
            Image img = null;
            byte[] memBytes = Convert.FromBase64String(text);
            IFormatter formatter = new BinaryFormatter();
            MemoryStream stream = new MemoryStream(memBytes);
            img = (Image)formatter.Deserialize(stream);
            stream.Close();
            return img;
        }
    }
}

[C++] 
#using <mscorlib.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>
#using <System.dll>
using namespace System;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Collections;
using namespace System::Drawing;
using namespace System::IO;
using namespace System::Reflection;
using namespace System::Runtime::Serialization;
using namespace System::Runtime::Serialization::Formatters::Binary;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::Design;

public __gc class TypeEventsTab;

// This component adds a TypeEventsTab to the Properties Window.
[PropertyTabAttribute(__typeof(TypeEventsTab), PropertyTabScope::Document)]
public __gc class TypeEventsTabComponent : public Component
{
public:
    TypeEventsTabComponent()
    {
    }
};

// This example events tab lists events by their delegate type.
public __gc class TypeEventsTab : public System::Windows::Forms::Design::EventsTab
{
private:
    [BrowsableAttribute(true)]
    // This string contains a Base-64 encoded and serialized example 
    // property tab image.
    String* img;
    IServiceProvider* sp;

public:
    TypeEventsTab(IServiceProvider* sp) : EventsTab(sp)
    {
        this->sp = sp;           
        String* s = S"AAEAAAD/////AQAAAAAAAAAMAgAAAFRTeXN0ZW0uRHJhd2luZywgVmVyc2lvbj0xLjAuMzMwMC4w"
            S"LCBDdWx0dXJlPW5ldXRyYWwsIFB1YmxpY0tleVRva2VuPWIwM2Y1ZjdmMTFkNTBhM2EFAQAAABVTeXN0ZW0uRHJhd2luZy5CaXRt"
            S"YXABAAAABERhdGEHAgIAAAAJAwAAAA8DAAAAtgIAAAJCTbYCAAAAAAAANgAAACgAAAANAAAAEAAAAAEAGAAAAAAAAAAAAMQOAADED"
            S"gAAAAAAAAAAAADO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tn/ztbZztbZHh4eHh4eztbZztbZztbZztbZztb"
            S"ZztbZztbZztbZztbZ/87W2c7W2QDBAB4eHh4eHs7W2c7W2c7W2c7W2c7W2c7W2c7W2c7W2f/O1tnO1tnO1tkAwQAeHh4eHh7O1tnO1"
            S"tnO1tnO1tnO1tnO1tnO1tn/ztbZztbZlJSU////AMEAHh4eHh4eztbZztbZztbZztbZztbZztbZ/87W2c7W2c7W2ZSUlP///wDBAB4"
            S"eHh4eHs7W2c7W2c7W2c7W2c7W2f/O1tnO1tnO1tnO1tmUlJT///8AwQAeHh4eHh7O1tnO1tnO1tnO1tn/ztbZHh4eHh4eHh4eHh4eH"
            S"h4e////AIAAHh4eHh4eztbZztbZztbZ/87W2ZSUlP///wDBAADBAADBAADBAADBAACAAB4eHh4eHs7W2c7W2f/O1tnO1tmUlJT///8"
            S"AwQAAgAAeHh4eHh7O1tnO1tnO1tnO1tnO1tn/ztbZztbZztbZlJSU////AMEAAIAAHh4eHh4eztbZztbZztbZztbZ/87W2c7W2c7W2"
            S"c7W2ZSUlP///wDBAACAAB4eHh4eHs7W2c7W2c7W2f/O1tnO1tnO1tnO1tnO1tmUlJT///8AwQAAgAAeHh4eHh7O1tnO1tn/ztbZztb"
            S"ZztbZztbZztbZztbZlJSU////AMEAAIAAHh4eHh4eztbZ/87W2c7W2c7W2c7W2c7W2c7W2c7W2ZSUlP///wDBAACAAB4eHs7W2f/O1"
            S"tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tnO1tn/Cw==";
        img = s;
    }

    // Returns the properties of the specified component extended with a 
    // CategoryAttribute reflecting the name of the type of the property.
    System::ComponentModel::PropertyDescriptorCollection* 
        GetProperties(ITypeDescriptorContext* /*context*/, Object* component, 
        System::Attribute* attributes[])
    {            
        // Obtain an instance of the IEventBindingService.
        IEventBindingService* eventPropertySvc = dynamic_cast<IEventBindingService*>(sp->GetService(__typeof(IEventBindingService)));

        // Return if an IEventBindingService could not be obtained.
        if (eventPropertySvc == 0)             
            return new PropertyDescriptorCollection(0);

        // Obtain the events on the component.
        EventDescriptorCollection* events = 
            TypeDescriptor::GetEvents(component, attributes);       

        // Create an array of the events, where each event is assigned 
        // a category matching its type.
        EventDescriptor* newEvents[] = new EventDescriptor*[events->Count];
        for(int i=0;i < events->Count;i++)
        {
            Attribute* temp[] = {new CategoryAttribute(events->Item[i]->EventType->FullName)};
            newEvents->Item[i] = TypeDescriptor::CreateEvent(events->Item[i]->ComponentType, events->Item[i], temp);
        }
        events = new EventDescriptorCollection(newEvents);

        // Return event properties for the event descriptors.
        return eventPropertySvc->GetEventProperties(events);
    }        

    // Provides the name for the event property tab.
    __property String* get_TabName()
    {
        return S"Events by Type";
    }


    // Provides an image for the event property tab.
    __property System::Drawing::Bitmap* get_Bitmap()
    {
        System::Drawing::Bitmap* bmp = new System::Drawing::Bitmap(DeserializeFromBase64Text(img));
        return bmp;
    }

    // This method can be used to retrieve an Image from a block of 
    // Base64-encoded text.
private:
    Image* DeserializeFromBase64Text(String* text)
    {
        Image* img = 0;
        Byte memBytes[] = Convert::FromBase64String(text);
        IFormatter* formatter = new BinaryFormatter();
        MemoryStream* stream = new MemoryStream(memBytes);
        img = dynamic_cast<Image*>(formatter->Deserialize(stream));
        stream->Close();
        return img;
    }
};

[Visual Basic, JScript] No example is available for Visual Basic or JScript. To view a C# or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Windows.Forms.Design

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Assembly: System.Windows.Forms (in System.Windows.Forms.dll)

See Also

EventsTab Members | System.Windows.Forms.Design Namespace

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