Hi,
The issue “Preview in taskbar showing ghost copy/move window” has been fixed.
The problem was caused by the popup windows involved. They were implemented as full-fledged forms (borderstyle=sizable or dialog, with minimize, restore, and maximize buttons in the title bar). When closed, these forms were not destroyed but simply hidden.
Because of this, the Desktop Window Manager (DWM) treated them as independent windows, making them eligible for taskbar previews. It also appears that DWM does not properly react when such windows are merely hidden.
I had 2 options to fix it:
- Convert their BorderStyle to SizeToolWindow or ToolWindow
- Destroy/free the windows on closure
By converting these windows to ToolWindows (or SizeToolWindows), the issue disappears. In this configuration, DWM considers them as dependent “slave” windows of the main form, and therefore excludes them from taskbar previews.
For the lightweight windows, I opted for destruction/freeing on closure, as those windows are not computing-power-demanding when (re)created.
The improvement will be part of this month’s release