如何在xaml中編寫ParentListBox.SelectedIndex？

Question

我有一個ListBox組合框作爲ListItems。每個ListItem中的組合框都是使用ListBox的ItemTemplate創建的。

現在，假設我有5個ListItems。即5個組合框。

For the 1st ListItem i.e. 1st ComboBox I would like to have all the Items from database as ItemsSource. 
For the 2nd ListItem i.e. 1st ComboBox I would like to have all the Items from database as ItemsSource. 
For the 3rd ListItem i.e. 1st ComboBox I would like to have only the selected Items from above Comboboxes as ItemsSource. 
For the 4th ListItem i.e. 1st ComboBox I would like to have only the selected Items from above Comboboxes as ItemsSource. 
For the 5th ListItem i.e. 1st ComboBox I would like to have only the selected Items from above Comboboxes as ItemsSource. 

所以，我認爲我必須爲不同的ComboBox使用不同的DataSource。

而要做到這一點，我有以下起始碼：

<ComboBox....> 
    <ComboBox.Style> 
     <Style> 
      <Style.Triggers> 
       <DataTrigger Binding="ParentListBox.SelectedIndex" Value="0"> 
        <Setter Property="DataSource" Value="{Binding Path=ListCorrespondingToValue1}"/> 
       </DataTrigger> 
       <DataTrigger Binding="ParentListBox.SelectedIndex" Value="Non-0"> 
        <Setter Property="DataSource" Value="{Binding Path=ListCorrespondingToValue2}"/> 
       </DataTrigger> 
      </Style.Triggers> 
     </Style> 
    <ComboBox.Style> 
</ComboBox> 

現在，我的問題是，我應該怎麼用的ParentListBox.SelectedIndex INSEAD在上面的代碼，我應該代之以非0？

Answer 1

你不使用的非零部分DataTrigger ......你只是把它作爲一個StyleSetter，使成爲默認值，然後DataTrigger改變DataSource財產只有當值是0。試試這個：

<ComboBox....> 
    <ComboBox.Style> 
     <Style> 
      <Setter Property="DataSource" Value="{Binding 
       Path=ListCorrespondingToValue2}"/> 
      <Style.Triggers> 
       <DataTrigger Binding="ParentListBox.SelectedIndex" Value="0"> 
        <Setter Property="DataSource" Value="{Binding 
         Path=ListCorrespondingToValue1}"/> 
       </DataTrigger> 
      </Style.Triggers> 
     </Style> 
    <ComboBox.Style> 
</ComboBox>