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Syncfusion Feedback

DockingManagerCtr.ActivateControl(myControl) fails sometimes in AHTabControl

Thread ID:





105238 Sep 20,2012 02:39 PM UTC Sep 24,2012 10:37 AM UTC WinForms 1
Tags: Tools
Mr. Sascha Wald
Asked On September 20, 2012 02:39 PM UTC


we are using Syncfusion 9.302.0.61

under some reproducable circumstances we get an error when we activate a control within the dockingmanager:

"System.NullReferenceException was unhandled
  Message="Object reference not set to an instance of an object."
       at Syncfusion.Windows.Forms.Tools.AHTabControl.SetClientControlSize(DockStateControllerBase ddcbase, Rectangle rcbounds)
       at Syncfusion.Windows.Forms.Tools.AHTabControl.StopShowAnimation()
       at Syncfusion.Windows.Forms.Tools.AHTabControl.ShowController(DockStateControllerBase ddcbase, Boolean banimate, Boolean bActivateAfterShow)
       at Syncfusion.Windows.Forms.Tools.DockingManager.ActivateControl(Control ctrl)"

In the Dockingmanager, we have a grid. And whenever a row is added to the grid, the panel containing the grid shall be shown.

Works good, except when we add rows and immediately toggle the AutoHide-Option manually from the dockingmanagers context menu. Then, the exception above raises up.

The control-parameter is always the same, so is the dockingmanager. I cannot see which object is not instanciated as it seems to me to be inside Syncfusion.

For a workaround, i wrapped the ActivateControl-Call up in a try-catch. This is not elegant.

Is there a way to check if I can activate a control within the dokingmanager (e.g, "CanActivateControl(ctrl)")?


btw: what is AHTabControl?




Berkunath A [Syncfusion]
Replied On September 24, 2012 10:37 AM UTC

Hi Sascha,
Thank you for your interests in Syncfusion products.
I am afraid that I am unable to reproduce this issue. Also I have created a simple sample to test this issue and it is available in the following link.
Sample :
Please have a look at the sample and if the issue still exists, could you please try reproducing it in the above sample or send reproducible sample and the reproducing steps so that we could sort out the cause of the issue and provide you the solution?
Please let us know if you have any concerns.
Berkunath A 



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