Gets or sets an option that controls how automatic completion works for the ComboBox.
published property AutoCompleteMode: TAutoCompleteMode read GetAutoCompleteMode write SetAutoCompleteMode default TAutoCompleteMode.acmNone;
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.
If you set ComboBoxStyle to DropDownList, the list displays only if AutoCompleteMode is Suggest or SuggestAppend.
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.