计算ComboBox的DropDown部分中匹配的建议项的数量

Question

In my ComboBox I set:

• datasource = [bindingsource]
• DisplayMember and ValueMember
• AutoCompleteSource = ListItems
• AutoCompleteMode = Suggest

How can I get the number of suggested items in the DropDown portion, after entering text in the ComboBox?

For example, I type "how" and the DropDown list suggests 5 matching items. How can I grab this number?

Answer 1

I don't see any property on the ComboBox control that gives you access to that information.

However, you should be able to do the same search against your ComboBox's DataSource that the ComboBox is doing internally, using a little LINQ:

var matches = comboBox1.Items.Cast<DataRowView>()
                       .Count(x => Convert.ToString(x["SomeColumn"])
                                          .StartsWith(comboBox1.Text))

Add the following using directive to the top of your class, if it's not there already:

using System.Linq;