Incremental Filtering

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The ASPxComboBox editor enables users to filter list items dynamically, based upon the text typed into the editor's input box on the client side (find-as-you-type filtering). The following filter modes are available, controlled by the ASPxAutoCompleteBoxBase.IncrementalFilteringMode property:

  • None

    Filtering is not applied to list items.

  • StartsWith

    The editor is filtered for list items that begin with the search string.

  • Contains (implemented in v2010 vol 1)

    The editor is filtered for list items that contain the search string. The search string results are highlighted within items for clarity.

The following image shows the 'Contains' filter in action:

asp-combo-incremental-filter.png

Note that in 'Contains' filter mode, the filter searches for the value (typed by a user in the edit box) within the editor's item list, based upon the ASPxAutoCompleteBoxBase.TextFormatString property's defined format.

Delayed Filtering

You can define the time interval between the time a user starts typing within the editor's edit box, and when the filter is applied. Use the ASPxAutoCompleteBoxBase.IncrementalFilteringDelay property for this purpose.

Moreover, when the ASPxComboBox editor is in incremental filter mode, you can specify the minimum number of symbols a user must type before the editor applies a filter (see the ASPxAutoCompleteBoxBase.FilterMinLength property).

This behavior is useful when the ASPxComboBox works with a large amount of data. If the editor applies a filter each time a user types a character, this can affect website performance when working with large data sets. Since the ASPxAutoCompleteBoxBase.FilterMinLength property allows you to control when to apply a filter, it can display more accurate results and improve page performance.