ComboDropDown - suppress dropdown event

[Administrator]

Hi,

I am experiencing some unusual behaviour with the combodropdown control and I just want to check that my code is correct before I proceed with an incident.

I am hosting a datagridview within a combodropdown control and in certain circumstances I need to suppress the drop down event, although the user should still be able to enter text into the textbox portion at all times.

The two lines of code that I have attempted to use both together and separately are shown below:

ComboDropDown1.DropDownButton.Enabled = False
ComboDropDown1.SuppressDropDownEvent = True

These lines seem to work most of the time, but on random occassions a dropdown event seems to get triggerred, or at least the dropdown portion appears to drop down without the corresponding event being triggered. My colleague running a quad core Windows 7 PC in test can force a drop down event even when the two properties above are set either individually and singly, quite easily. On my PC running a dual core processor and Windows Vista the event can only be forced after a number of mouse clicks, usually around a dozen, some of which must be considered double clicks. I have found the quickest and most reliable way to force a dropdown event is by left and right clicking the mouse several times in quick succession.

Is this expected behaviour or are there other properties that I need to set to achieve the desired behaviour of suppressing the dropdown event?

I have a small VB.Net 2005 project which illustrates the behaviour if required.

Thanks for your help,

Regards,

Steve Graham

[Administrator]

My Apologies but could you move this thread to the Windows Forms forum please?

Thanks,

Steve G

[Jeraldes J]

Hi Steve,

Thanks for your interest in Syncfudion Products.

Could you please tell the Syncfusion Version in which you are using this ComboDropDown. We would be glad to help you on this.

Please let us know if you need any other details.

Regards,
Jeraldes J

[Administrator]

Hi Jeraldes,

My apologies for the delay in replying. I am currently using Essential Tools - version 8.302.0.21, the release just before the last one.

Regards,
Steve G

[Iniyen M A]

Hi Steve,

Thanks for your interest in Syncfudion Products.

You can block the user from entering the text in the text portion of the ComboDropDown control by setting its style to DropDownList.
We are unable to reproduce the reported behavior on SupperssDropDownEvent with the details provided, I have attached the sample I used to test the behavior under the following link. Could you please modify the sample to demonstrate the behavior and sent it to us. We would be glad to help you on this.

[Sample Link]

http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=Sample-688112334.zip

Please let us know if you need any other details.

Regards,
Iniyen M.A.

[Administrator]

Hi Iniyen,

Thanks for the sample. Unfortunately we are still developing in VB.NET using VS2005 (your sample is C# using VS2010), so I am not able to load your sample. However, I have attached a very simple VB.NET project using VS2005 which demonstrates the problem.

When the application is running, move the mouse over the combobox drop down button and left/right click rapidly several times to cause the drop-down event to trigger, despite the fact that both the drop down button is disabled and the drop down event is suppressed.

Please let me know if I can be of further help.

Regards,

Steve G



Bug 0249M_d6f8f869.zip

[Iniyen M A]

Hi Steve

We are able to reproduce the issue and we will be fixing it in our upcoming release. If you are interested in getting a patch for this issue, you may create a Direct Trac incident and we will be able to share the patch with you

Please login into http://www.syncfusion.com/Account/ to create a Direct Trac incident and also to have a better track on your issue.

Regards,
Iniyen M.A.

[Administrator]

Hi Iniyen,

Thank you very much for the update. I will submit an incident shortly.

Note: for anyone else having the same problem I have developed a temporary workaround by testing the conditions for a valid drop down event (e.g. an object being populated) and if the test fails, setting the drop down width to zero and sending the escape key as shown below. A bit of a hack but has worked OK for the last few weeks.

ComboBox1.DropDownWidth = 0
SendKeys.Send("{ESC}")

Thanks again,

Steve G

[Jeraldes J]

Hi Steve

Thanks for your update.

We are gladly waiting for your Incident Post.

Regards,
Jeraldes J