C # enable ComboBox to automatically match characters

1. Use CustomSource as the prompt set
Add the following code to the window loading function. Assume that unitNameList is the obtained string list to be added to the drop-down list.

AutoCompleteStringCollection collection = new AutoCompleteStringCollection ();
// Obtain the unit list
List <string> unitNameList = this. getAllUnitName ();
Foreach (string unitname in unitNameList)
{
Collection. Add (unitname );
// Console. WriteLine ("automatic prompt" + unitname );
}
This. comboBox2.AutoCompleteCustomSource = collection;
This. comboBox2.AutoCompleteSource = AutoCompleteSource. CustomSource;
This. comboBox2.AutoCompleteMode = AutoCompleteMode. SuggestAppend;

The AutoCompleteMode includes None, Suggest, Append, and SuggestAppend.
None: Disable auto-completion.

Suggest: Expand the drop-down list and display matching results

Append: auto-completion

SuggestAppend: the combination of Suggest and Append. This means that the drop-down list is automatically completed.

2. directly use the items in the drop-down list as the matching set
Set AutoCompleteSource to ListItems.

// Obtain the unit list
List <string> unitNameList = this. getAllUnitName ();
Foreach (string unitname in unitNameList)
{
This. comboBox2.Items. Add (unitname );
}
This. comboBox2.AutoCompleteSource = AutoCompleteSource. ListItems;