Dynamically setting column names on an editable grid (Babar Ismail)

re: Dynamically setting column names on an editable grid (Babar Ismail)

M.Radwan-MVP — Thu, 16 Aug 2012 23:20:27 GMT

This was really awesome... thank you :)

re: Dynamically setting column names on an editable grid (Babar Ismail)

Yann Duran — Fri, 27 Jul 2012 03:13:32 GMT

Thanks Babar!

re: Dynamically setting column names on an editable grid (Babar Ismail)

LightSwitch Team — Thu, 26 Jul 2012 19:11:04 GMT

Thanks Yann for your comment.. The intention of this post was to explain how we can achieve a certain functionality in LightSwitch. I used this example to simplify things and not to suggest it is ok to design databases like that. But I understand where you're coming from and is definitely something to keep in mind.

Thanks,

Babar

re: Dynamically setting column names on an editable grid (Babar Ismail)

Babloo1436 — Thu, 26 Jul 2012 19:06:30 GMT

@Babar

I really appreciate that you updated the code sample.

Yes. The Updated code is working fine. And ofcource this is really a very useful post.

Thank You Babar

Thanks LightSwitch Team

re: Dynamically setting column names on an editable grid (Babar Ismail)

Yann Duran — Thu, 26 Jul 2012 10:53:56 GMT

Hi Babar,

Thanks for the blog post, but I really wish that such explanations were based on something a little more "real world" than a table with properties like Car1, Car2, Car3 etc. That's an example of an really badly designed table. If someone who's new to programming sees properties like this in an example, they're likely to think it's ok to create their tables the same way, because they see a member of the LS team doing it.

I spent years trying to "fix" tables like that in Access for clients, because the people who created them didn't know any better.

I'm also glad to see that you ammended your code to not be trying to access a control before the screen has been "created". Yes, you may get away with it some of the time (or even most of the time), but it's the times when it doesn't work that will have people baffled.

This article would be much more useful if it described a "real" scenario, with well-designed tables.

I'm sorry if I sound negative, I do appreciate members of the team taking the time to write these posts, but I also hope you understand what I'm getting at.

re: Dynamically setting column names on an editable grid (Babar Ismail)

LightSwitch Team — Thu, 26 Jul 2012 00:53:51 GMT

i have updated the blog post with new code. Our findcontrol method is now being called in Screen_Created method and UpdateColumnNames also has a little different implementation.

Babloo... let me know if the new code works for you.

Mr Yossu.. I have also moved the call to UpdateColumnNames method into the ControlAvailable event handler. Hope this solves the problem.

Thanks,
Babar

re: Dynamically setting column names on an editable grid (Babar Ismail)

LightSwitch Team — Wed, 25 Jul 2012 18:13:51 GMT

I haven't encountered this issue in V2 so far although I have used code quite similar to this extensively in an app I have been working on.

If you are encountering such issues then you can move it Screen_Created() method.

Thanks,

Babar

re: Dynamically setting column names on an editable grid (Babar Ismail)

Babloo1436 — Wed, 25 Jul 2012 16:08:26 GMT

@Yossu

Thank you for your answer.

It helps me to understand correctly.

Thanks

re: Dynamically setting column names on an editable grid (Babar Ismail)

Mr Yossu — Wed, 25 Jul 2012 13:04:00 GMT

In the CarRatingsGridScreen_InitializeDataWorkspace method, you use FindControl to subscribe to the ControlAvailable event, and then immediately call UpdateColumnNames() from the same method.

If the grid isn't available when the CarRatingsGridScreen_InitializeDataWorkspace method fires (which is quite possible), then you'll get the InvalidOperationException thrown.

Surely you should call UpdateColumnNames from CarRatingsGrid_ControlAvailable, because then you know the grid will be available (that's the point of the method after all). That way you're pretty much guaranteed not to get the exception.

Don't know if this helps you Babloo1436?

re: Dynamically setting column names on an editable grid (Babar Ismail)

thang — Wed, 25 Jul 2012 03:56:39 GMT

thanks !!!

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