Excel like FILTER feature in Silverlight datagrid?

Question

Hi

In Excel, there is this feature for filtering the cells of a column.

How can I implement excel like FILTER feature in Silverlight Datagrid?

Please advice. Thanks

AJ

Answer 1

Good question - this is a good feature, but not one that can be implemented in 5 minutes.

You don't want to be overriding the rendering of the standard datagrid in any way (too much work), so you need to take a slightly different approach. One way to do that is to draw your own 'header' above the top of the grid - just a grid, with a border and a stackpanel will get you started. Then you need to enumerate the visible columns of the grid, and create a dropdown corresponding to each, and add that dropdown to the stackpanel. Using a simple linq statement you can get a list of the distinct values in each column. When the user selects a value from the dropdown you can then filter the grid's datasource using that value in a LINQ statement.

In reality this is probably going to be at least a week's worth of work to do properly. If you take the cost of that development and the cost of the testing, and measure that against the cost of a good component suite where they already have filtering built in (most of the major vendors do), then unless you are working for a very low hourly rate you will find it is cheaper to buy the components - it is probably safer too, as the components will be well tested and realtively bug free.

Edit (some time later): what i should also mention though is that if you only want to do this on a couple of columns then you could consider using a column header template. If you take this approach though you will also have to do things like copy the various mouse related animations or transitions that might be part of the original colunm header, just so you can keep some consistency across the top of the grid. Personally i would just go with option one and give the user the ability to filter on any of the columns.