AutoCompleteCustomSource Property

ComboBox.AutoCompleteCustomSource Property


Gets or sets a custom System.Collections.Specialized.StringCollection to use when the AutoCompleteSource property is set to CustomSource.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public AutoCompleteStringCollection AutoCompleteCustomSource { get; set; }

Use the AutoCompleteCustomSource, AutoCompleteMode, and AutoCompleteSource properties to create a ComboBox that automatically completes input strings by comparing the prefix being entered to the prefixes of all strings in a maintained source. This is useful for ComboBox controls in which URLs, addresses, file names, or commands will be frequently entered. If there are duplicate entries in the maintained source, automatic completion behaves unpredictably.

The use of the AutoCompleteCustomSource property is optional, but you must set the AutoCompleteSource property to CustomSource in order to use AutoCompleteCustomSource.

You must use the AutoCompleteMode and AutoCompleteSource properties together.


The operating system might limit the number of custom strings that it can display at once. For strings that contain a forward slash (/) or backward slash (\), automatic completion appends all characters only up to and including the slash.

.NET Framework
Available since 2.0
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