PropertyValueUIItemInvokeHandler Delegate

Definition

Namespace:

System.Drawing.Design

Assembly:

System.Windows.Forms.dll

Source:

PropertyValueUIItemInvokeHandler.cs

Represents the method that will handle the InvokeHandler event of a PropertyValueUIItem.

public delegate void PropertyValueUIItemInvokeHandler(ITypeDescriptorContext ^ context, PropertyDescriptor ^ descriptor, PropertyValueUIItem ^ invokedItem);

public delegate void PropertyValueUIItemInvokeHandler(ITypeDescriptorContext context, PropertyDescriptor descriptor, PropertyValueUIItem invokedItem);

type PropertyValueUIItemInvokeHandler = delegate of ITypeDescriptorContext * PropertyDescriptor * PropertyValueUIItem -> unit

Public Delegate Sub PropertyValueUIItemInvokeHandler(context As ITypeDescriptorContext, descriptor As PropertyDescriptor, invokedItem As PropertyValueUIItem)

Parameters

context

ITypeDescriptorContext

The ITypeDescriptorContext for the property associated with the icon that was double-clicked.

descriptor

PropertyDescriptor

The property associated with the icon that was double-clicked.

invokedItem

PropertyValueUIItem

The PropertyValueUIItem associated with the icon that was double-clicked.

Examples

The following code example provides a PropertyValueUIItem object for any properties of the component named HorizontalMargin or VerticalMargin. The PropertyValueUIItem for these properties provides an image, a ToolTip, and an event handler that displays a message box when the image for the property is clicked. This code example is part of a larger example provided for the IPropertyValueUIService interface.

// PropertyValueUIHandler delegate that provides PropertyValueUIItem
// objects to any properties named HorizontalMargin or VerticalMargin.
private void marginPropertyValueUIHandler(
    System.ComponentModel.ITypeDescriptorContext context,
    System.ComponentModel.PropertyDescriptor propDesc,
    ArrayList itemList)
{
    // A PropertyValueUIHandler added to the IPropertyValueUIService
    // is queried once for each property of a component and passed
    // a PropertyDescriptor that represents the characteristics of 
    // the property when the Properties window is set to a new 
    // component. A PropertyValueUIHandler can determine whether 
    // to add a PropertyValueUIItem for the object to its ValueUIItem 
    // list depending on the values of the PropertyDescriptor.
    if (propDesc.DisplayName.Equals("HorizontalMargin"))
    {
        Image img = Image.FromFile("SampImag.jpg");
        itemList.Add(new PropertyValueUIItem(img, new PropertyValueUIItemInvokeHandler(this.marginInvoke), "Test ToolTip"));
    }
    if (propDesc.DisplayName.Equals("VerticalMargin"))
    {
        Image img = Image.FromFile("SampImag.jpg");
        img.RotateFlip(RotateFlipType.Rotate90FlipNone);
        itemList.Add(new PropertyValueUIItem(img, new PropertyValueUIItemInvokeHandler(this.marginInvoke), "Test ToolTip"));
    }
}

Remarks

Double-clicking an icon in the Properties window will raise the InvokeHandler event of the PropertyValueUIItem that the icon is associated with. The InvokeHandler event typically launches a user interface (UI) to edit the property's value. Add a PropertyValueUIItemInvokeHandler to the InvokeHandler property of a PropertyValueUIItem to assign an event handler to perform the appropriate behavior when the icon displayed next to the property name is double-clicked.

When you create a PropertyValueUIItemInvokeHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Handling and Raising Events.

Extension Methods

See also

• ITypeDescriptorContext
• PropertyValueUIItem
• IPropertyValueUIService