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BM
300
DataPresenterCommand CanExecute in XamContextMenu (of XamDataGrid) not updating
posted

Hi,

We have come across an issue where we have a DataPresenterCommand (copy) in a context menu within a XamDataGrid. The XamDataGrid data is populated via long running worker thread in ViewModel.

The issue we have is we also have a 'Select All' command in the context menu that runs in code behind setting all records to IsSelected = true; When a user clicks Select All, the UI updates but the DataPresenterCommand does not enable. Our users presume that a Ctrl + C shortcut works (as the context menu automatically displays) as the UI is reflecting the selection but the command is still not active - so no selection is actually made.

If a user selects a single row (click on grid) once the grid is populated, then the Command (and ctrl+c shortcut) enable. As such, to select all, user must first click on a single item, then select all (via context menu) then Copy (via context or Ctrl + C). Obviously this behaviour isn't intuitive.

Strangely enough, if I add a separate button which also has the copy command binding, this does enable once the SelectAll method has run however the Ctrl+C shortcut is not available.

I've attached an example application highlighting the issue. Could you please take a look.

XamDataGridNavigation.zip
  • 34430
    Offline posted

    Hello BM,

    Thank you for your post.

    It appears that the reason that this is happening is a focus-related one. Internally, the clipboard-related DataPresenterCommands (Copy, Cut, Paste, etc.) require the XamDataGrid to be focused for their CanExecute method to return true in the case of a context menu. While the XamContextMenu does appear on right click of the grid, this does not appear to focus the grid. My recommendation to prevent this would be to make a call to MyXamDataGrid.Focus() after running your Select-All related code. Alternatively, you could also hook into the XamDataGrid's PreviewMouseRightButtonDown event, and call MyXamDataGrid.Focus() there to focus the grid just before the XamContextMenu shows.

    I have attached a modified version of the sample project you had sent me to demonstrate the above.

    I hope this helps you. Please let me know if you have any other questions or concerns on this matter.

    Sincerely,
    Andrew
    Associate Developer
    Infragistics Inc.
    www.infragistics.com/support

    WpfApplication1.zip