将XamlComboBox强制转换为继承的类型

Question

I am trying to cast a CodedUI XamlControl to a Type of a XamlComboBox but the cast throws a unable to cast exception.

My class is:

public class MyComboBox : XamlComboBox

The error occurs when i try to iterate over a List<XamlControl> in the following line:

var comboBox = (MyComboBox) element;

Even when i try something weird like this:

var xamlComboBox = (XamlComboBox) element;
var comboBox = (MyComboBox) xamlComboBox;

the error still hapens at cast to MyComboBox

Any idea, why this is happening?

Answer 1

Before your iteration filter all items, which are not of type MyComboBox :

List<XamlControl> controls = ...
foreach (var comboBox in controls.Where(c => c is MyComboBox)) {
    // Here the items are only of type MyComboBox
}