WinExplorerView.GetThumbnailImage Event
Allows you to asynchronously assign an image to a WinExplorerView record.
Namespace: DevExpress.XtraGrid.Views.WinExplorer
Assembly: DevExpress.XtraGrid.v22.2.dll
NuGet Package: DevExpress.Win.Grid
Declaration
Event Data
The GetThumbnailImage event's data class is ThumbnailImageEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| DataSourceIndex | Gets the index of the currently processed item among other items in the source (the item’s index in the bound data source for data-aware controls, e.g., GridControl). |
| DesiredThumbnailSize | Stores the desired size of thumbnail images, generated using the ThumbnailImageEventArgs.CreateThumbnailImage method. |
| ThumbnailImage | Gets or sets the image that will be assigned to an item that fired this event. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| CreateThumbnailImage(Image, Size) | Creates a thumbnail image of the specific size. This image will be later assigned to an item that supports the asynchronous image load feature. |
| CreateThumbnailImage(Image) | Creates a thumbnail image that will be assigned to an item that supports the asynchronous image load feature. |
| ResetImageCache() | Resets the image cache and causes all items that are not currently visible to reload their images when displayed again. |
Remarks
The GetThumbnailImage event is raised each time a WinExplorerView record needs to display its image and both of the following conditions are met:
- the image must be loaded asynchronously (the WinExplorerViewOptionsImageLoad.AsyncLoad property equals true),
- the image must not be taken from the grid View data source (the WinExplorerViewOptionsImageLoad.LoadThumbnailImagesFromDataSource property equals false) or was not found in it.
The event allows you to create a required image by using the ThumbnailImageEventArgs.CreateThumbnailImage method and assign the generated image to the ThumbnailImageEventArgs.ThumbnailImage property. See the Asynchronous Image Load in Data Grid topic to learn more.
Important
The GetThumbnailImage event is raised from a non-UI thread.