This documentation is archived and is not being maintained.

TextBox.AutoCompleteMode Property

Note: This property is new in the .NET Framework version 2.0.

Gets or sets an option that controls how automatic completion works for the TextBox.

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

public AutoCompleteMode AutoCompleteMode { get; set; }
/** @property */
public AutoCompleteMode get_AutoCompleteMode ()

/** @property */
public void set_AutoCompleteMode (AutoCompleteMode value)

public function get AutoCompleteMode () : AutoCompleteMode

public function set AutoCompleteMode (value : AutoCompleteMode)

Property Value

One of the values of AutoCompleteMode. The values are Append, None, Suggest, and SuggestAppend. The default is None.

Exception typeCondition


The specified value is not one of the values of AutoCompleteMode.

Use the AutoCompleteCustomSource, AutoCompleteMode, and AutoCompleteSource properties to create a TextBox 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 TextBox controls in which URLs, addresses, file names, or commands will be frequently entered.

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.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0