In Telerik RadGrid you can enable filtering for template columns
automatically - just set
AllowFilteringByColumn = true for the entire grid and you
should be done. Also make sure that the
AllowFiltering property of the template column
is set to
true (this is the default value). On this online demo the
template column in question is
TemplateColumn City.
Keep in mind that you will need to set the
DataField property for the column to a valid data
field from the datasource. This ensures that the control properly retrieves the data
on which the filtering pattern will be applied.
Alternatively, you can extend the default
GridTemplateColumn class (part of the Telerik RadGrid object model) and add a
textbox control to it. Thus you will be able to filter the GridTemplateColumn values in exactly
the same way as with other Telerik RadGrid column types. See the code under the
ASPX/C#/VB.NET
tags for further reference.
And here are some additional helpful resources:
Filter list options
Grid known filter functions
Filtering with template column
Controls - RadGrid - Filtering -> How-to chapter
Finally, for some swift integration examples with Telerik RadComboBox
("Google suggest" filtering or "Load on demand" grid in combobox) you can visit the links below:
"Google suggest" filtering
"Load on demand" grid in combobox