Image list

The attributes and functions explained on this page can be found in the List category.

Property: ImageListVisible

The ImageListVisible property can be used to hide and show the image list. If the list is hidden, the toolbar takes up the entire area of the control. As the control is initialized in portrait format, the height should be adjusted for this case.

Image list

The image list shows an entry for all temporarily saved history images if ImageFreeze of the linked ImageWatch control is activated. The index number and timestamp are displayed in the list for each image. The timestamp is from the time at which the corresponding image was received by the ImageWatch control. As a prerequisite, the QueueSize of the ImageWatch control must be greater than 0.

In the following cases, an alternative text is displayed instead of the image list:

• If no ImageWatch control is linked: "Link an ImageWatch control to use the image history"
• If ImageFreeze is not active: "Activate freeze to show the image history"
• If the history queue is empty: "The image history queue is empty"

The topmost list entry always represents the current, most recently received image. An image can be chosen by clicking on an entry. The image selected in the list is highlighted and displayed in the linked ImageWatch control.

Performance

When ImageFreeze of the ImageWatch control is activated for the first time, the image list of the History control is created. For larger QueueSize values and depending on the system performance, this may require more time. Each time ImageFreeze is activated, only the list entries are updated, provided the number of entries remains the same, which is much faster. We therefore recommend that you do not select QueueSize too large.

Properties for customizing the font

The ListFontFamily, ListFontSize, ListFontStyle and ListFontWeight properties are available to customize the list stylistically.