c# event subscription: ordering subscribers

Question

I have a wpf app which shows a custom combobox. The inner Textbox of the ComboBox subscribes to the TextChanged eventhandler. Additionally, the ComboBox is attached to a textfiltering behavior. It also subscribes to the textChanged eventhandler.

Now the scenario is:

1. app xaml is parsed and Static Resources (Styles) are created: --> inner TextBox is 1st subscriber of TextChanged.
2. the ComboBox xaml is parsed: behavior attaches --> It becomes 2nd subscriber of TextChanged

Now you guess it right: I like the behavior to be the 1st subscriber, since it does the filtering and the combobox operates on the filtering results.

Event subscription is placed here: 1) Style (as StaticResource)

<Style x:Key="MyComboBoxStyle" TargetType="ComboBox">
 ...
    <controls:TextBox x:Name="PART_EditableTextBox"
     ...
        TextChanged="PART_EditableTextBox_TextChanged"/>
</Style>

2) behavior attaches to runtime combobox object:

<myctrl:MyComboBox>
 ...
    <behaviors:FilterBehavior.TextBox="{Binding ElementName=PART_EditableTextBox}">
</myctrl:MyComboBox>

No option: mix behavior / combobox code, since the behavior is used to filter other textinput controls.

Can I force a subscriber to be the 1st / last of the invocation list ?

Answer 1

Since i learned the invocation list is mostly dispatched in order of subscription, but there's no guarantee for it, I now use a KeyUp handler rather than OnTextChanged. Thanks to Sriram for the hint!