Setting tab order in WPF

If you want to explicitly set the tab ordering for elements in your form, the following attached property is supposed to help:

<Control KeyboardNavigation.TabIndex="0" ... />

I say "supposed to help" as I haven't found it very reliable though I probably need to read more about how it is intended to be used. I only post this half baked answer because no one else mentioned this property.

Note that in Win RT, the property is just TabIndex="0".

You can skip elements in the tab sequence by setting KeyboardNavigation.IsTabStop on the element in XAML.

KeyboardNavigation.IsTabStop="False"

You can setup a trigger that would toggle this property based on the expanded state.

<Control KeyboardNavigation.TabIndex="0" ... /> Works perfectly fine...For example-

<ComboBox Height="23"           Margin="148,24,78,0"           Name="comboBoxDataSet"          VerticalAlignment="Top"          SelectionChanged="comboBoxDestMarketDataSet_SelectionChanged"          DropDownOpened="comboBoxDestMarketDataSet_DropDownOpened"          KeyboardNavigation.TabIndex="0" /><ComboBox Height="23"           Margin="148,56,78,0"           Name="comboBoxCategory"           VerticalAlignment="Top"           SelectionChanged="comboBoxDestCategory_SelectionChanged"          DropDownOpened="comboBoxDestCategory_DropDownOpened"          KeyboardNavigation.TabIndex="1" />

Will allow you to navigate through these two combo boxes using TAB key.