3rd Party Silverlight Grid Control_问答_开发者

We are going through a process of selecting a 3rd party suite of controls for Silverlight 4.0. We're mostly interested in a feature-rich grid control. I'm surprised to find that most of the products out there focus on client side paging, filtering, sorting, and grouping. But if the dataset is large enough to benefit from these functions isn't also too big to bring to the client in one call? And doesn't this make most of the advertised fancy grid features useless? In my opinion 200 rows of data is ideal upper limit on how much I'd request from the server in one request. Yet the sites for Telerik, DevExpress, ComponentOne, Xceed, and others all have fancy demos that bring 10,000+ rows of data to the client and show off the ability to page, filter, group, and sort it. Who brings 10,000+ rows of data to the client? What if you have 1,000s of concurrent users? What if that data is volatile? What use-case does this really address?

Can you share your experien开发者_运维百科ces with any of these control suites and whether you've implemented paging? Also whether you are using RIA?

Thanks.

You don't need a third party Grid control to achieve server side paging. You can use the grid control and ObjectDataSource provided by silverlight toolkit http://silverlight.codeplex.com/

http://borrell.parivedasolutions.com/2008/01/objectdatasource-linq-paging-sorting.html

I agree with you, it can be crazy for a client to want to view their entire years worth of data all at the same time, but sometimes the client (and product managers) don't see things the same way you do and insist upon doing stupid things....

In any case, just because the demo is paging through 1 million records that doesn't mean they are bringing them all to the client. You also have to consider the scenario where you have 200 rows worth of data but you can only show 10 rows at a time due to the data templates you are using (you may only fit 10 rows to a page) - you can still retrieve all 200 rows because it is simply your presentation that is using up the physical room. You can also implement paging and retrieve the next page worth of data when it is requested (which will introduce a small delay, but could be well worth it). Possibly the best way to deal with this is to not give the user the ability to retrieve squillions of records at once - if you give them that feature they will use it and then they will also complain about its performance.

As for fast client side sorting/grouping/filtering, that is a real world necessity. It is common for our users to fetch many thousands of records from the server, then use the filters (which i have extended) to view a handful of records at a time, operate on those records, then modify the filters to view a different bunch. It is important to have these functions working fast because it makes a huge difference to the user experience. I trialled several different component sets earlier this year and found there was a vast difference in the performance between them when it came to these functions, so choose wisely :)

I'd like to see a control suite that boast working with concurrency issues on order fullfullment and also uses queues or stacks in order to solve data conflicts. I see too often that this grids and list controls are really nice, pretty, and show you all the data, but they don't solve basic concurreny problems when you have more than one person working on the same set of data. If it automates the locking of a row of one user from another, prevents duplication of work, and automatically logs error messages, then I can see purchasing the control suite.

You don't need to load all your data at once you can specify a maximum load in the xaml of your ObjectDataSource. This will load your data in blocks of the specified size. Take a look at the 2 RIA services videos here: https://www.silverlight.net/getstarted/riaservices/

There are segments on paging which may also be useful to you.

note(some of the assembly references and syntax have changed slightly since these videos were made but the core function is still the same)