The ComboBox does not respond to the drop-down operation in the Prism child window.

[swk314]

I created a child window through Prism and added a ComboBox and a TextBlock control to the window. The TextBlock is used to display the SelectedValue of the ComboBox. Why doesn't the ComboBox respond to the mouse click drop-down operation, but it does respond to the mouse scroll operation? However, the same code works fine when copied to the main window.

1. axaml code:

		<ComboBox ItemsSource="{Binding Operators}" Width="300" Foreground="#666"
		  MaxDropDownHeight="300" MinHeight="20" DisplayMemberBinding="{Binding Header}" SelectedValueBinding="{Binding Value}"
		  SelectedValue="{Binding Operator}"/>
		<TextBlock Width="30" Text="{Binding Operator}" HorizontalAlignment="Right"/>

2. ViewModel code:

        public List<ConditionOperatorModel> Operators { get; set; } = new List<ConditionOperatorModel>()
        {
            new ConditionOperatorModel() { Header = "Greater than", Value = ">" },
            new ConditionOperatorModel() { Header = "Less than", Value = "<" },
            new ConditionOperatorModel() { Header = "Equal", Value = "==" },
            new ConditionOperatorModel() { Header = "Greater than or equal", Value = ">=" },
            new ConditionOperatorModel() { Header = "Less than or equal", Value = "<=" },
            new ConditionOperatorModel() { Header = "Not equal", Value = "!=" }
        };

        private string _operator = ">";
        public string Operator
        {
            get { return _operator; }
            set { SetProperty(ref _operator, value); }
        }

[swk314]

The parent window intercepts the mouse events.