ShellFilePreview Class

Use this component to display a preview of a file. Depending on the installed PreviewHandlers not all files types support a preview. If no preview is registered, a thumbnail of the file is shown. You may either use the Path property to set a path to a file to load the preview or you may synchronize it to a ShellListView or ShellTreeView component using the ShellControlConnector property.

Inheritance Hierarchy

SystemObject
  SystemMarshalByRefObject
    System.ComponentModelComponent
      System.Windows.FormsControl
        Jam.ShellShellFilePreview

Namespace: Jam.Shell
Assembly: ShellBrowser (in ShellBrowser.dll) Version: 7.1

Syntax

C++

Copy

public class ShellFilePreview : Control, 
	IShellControl, IShellControlConnectorTarget, ISupportInitialize, ISupportInitializeNotification, ICommonPreviewHandlerHost

Public Class ShellFilePreview
	Inherits Control
	Implements IShellControl, IShellControlConnectorTarget, ISupportInitialize, ISupportInitializeNotification, 
	ICommonPreviewHandlerHost

public ref class ShellFilePreview : public Control, 
	IShellControl, IShellControlConnectorTarget, ISupportInitialize, ISupportInitializeNotification, ICommonPreviewHandlerHost

type ShellFilePreview =  
    class
        inherit Control
        interface IShellControl
        interface IShellControlConnectorTarget
        interface ISupportInitialize
        interface ISupportInitializeNotification
        interface ICommonPreviewHandlerHost
    end

The ShellFilePreview type exposes the following members.

Constructors

	Name	Description
	ShellFilePreview	Initialialises a new instance of the ShellFilePreview class.

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Properties

	Name	Description
	AutomaticRefresh	Controls whether the component automatically reloads the preview when the file is changed. "
	DisplayMsg	Gets or sets a message that is displayed in the component if no preview is currently being displayed.
	IsInitialized	Indicates whether the component is initialized.
	ItemIdList	Gets or sets the absolute ItemIdList that is previewed.
	NoPreviewAvailableMessage	Gets or sets a message to be displayed if the item to be previewed is not supported.
	Path	Gets or sets the path of the file that is displayed.
	PreviewNotPossibleMessage	Gets or sets a message to be displayed if loading the preview failed.
	SelectFileMessage	Gets or sets a message to be displayed when no item is active.
	ShellControlConnector	ShellControlConnector for this class. Set this property to the same ShellControlConnector instance of a ShellListView, ShellTreeView or ShellSystemList to keep the ShellFilePreview in sync with these components. It will then always preview the selected file.
	Version	The current version of the ShellBrowser.

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Methods

	Name	Description
	BeginInit	Signals the object that initialization is starting.
	Clear	Clears the preview
	Dispose	Disposal method for the object that also cleans up resources that are used. (Overrides ControlDispose(Boolean).)
	EndInit	Signals the object that initialization is complete.
	FolderChanged	Called by ShellControlConnector when the current folder has changed.
	FullRefresh	Forces the reload of the current file.
	GetDisplayRect	Gets display rectangle.
	GetSynchronizationContext	PreviewHost must provide its SynchronizationContext to be used by async events.
	GetWindowHandle	Gets window handle.
	GoUp	Not supported.
	OnAfterPreviewLoaded	Calls the AfterPreviewLoaded event.
	OnCommonPreviewHandlerLoaded	Controls implementing this interface must implement this eventhandler, which is called after the preview has been loaded.
	OnCreateControl	Raises the CreateControl method. (Overrides ControlOnCreateControl.)
	OnEnabledChanged	While disabled the control only stored the current filename. On enabling a FullRefresh is triggered. (Overrides ControlOnEnabledChanged(EventArgs).)
	OnHandleDestroyed	Raises the HandleDestroyed event. (Overrides ControlOnHandleDestroyed(EventArgs).)
	OnLoadPreview	Calls the LoadPreview event.
	OnPaint	Paints the error message text on the ShellFilePreview control. (Overrides ControlOnPaint(PaintEventArgs).)
	OnResize	Passes the resize event to the current PreviewHandler (Overrides ControlOnResize(EventArgs).)
	Open	Opens the path that is passed with the matching preview handler.
	Refresh(RefreshLevel)	Refreshes the control.
	Refresh(RefreshLevel, ItemIdList)	Refreshes the control.
	SelectedFileChange	Called by ShellControlConnector when the selected file has changed.
	SmartRefresh	Forces the reload of the current file. There is no difference compared to FullRefresh.

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Events

	Name	Description
	AfterPreviewLoaded	Event that occurs after the preview has been loaded.
	Initialized	Occurs when initialization of the component is completed.
	LoadPreview	Event is thrown when a file is previewed. It can be implemented to set a custom preview control.

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Fields

	Name	Description
	WebPreviewHandler	The GUID of the WebPreviewHandler class.

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Extension Methods

	Name	Description
	HandleNeeded	A Control extension method that ensures that the handle for a control is created. (Defined by ExtensionMethods.)
	ScaledPixels	An extension method for controls: It scales the passed pixels according to the current dpi the control is displayed with. (Defined by ExtensionMethods.)
	ScaleFont	A Control extension method that scales font according to the passed factor. (Defined by ExtensionMethods.)

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Remarks

The component is using the Preview Handlers registered in the system to display the files, so that normally the same files that Windows Explorer can preview should be supported. There are occasional problems concerning the bitness of the application using the ShellFilePreview vs. the bitness of the PreviewHandler registered for a filetype. With the LoadPreview event it is also possible to use existing PreviewHandlers to display other file extensions. If you want to preview Microsoft Outlook .msg files and only the header is displayed, make sure to have Visual Styles enabled for your application. Call "Application.EnableVisualStyles()" or change your application manifest accordingly.

Reference

Jam.Shell Namespace