Formating AutoCompleteBox DropDown

Question

這必須是超級簡單，只是想念它。我有一個自動完成框，它沒有填充框的整個空間;

黃色框被添加到圖像，而不是實際程序的一部分。添加每行的邊框以直觀地查看每個正在使用的空間。這裏是DataTemplate的XML;

<Border Height="Auto" BorderBrush="Black" BorderThickness="1" > 
<Grid HorizontalAlignment="Stretch"> 
    <Grid.ColumnDefinitions> 
     <ColumnDefinition Width="5*"/> 
     <ColumnDefinition Width="3*"/> 
     <ColumnDefinition Width="2*"/> 
    </Grid.ColumnDefinitions> 
    <StackPanel Grid.Column="0"> 
     <Grid> 
      <Grid.ColumnDefinitions> 
       <ColumnDefinition Width="Auto"/> 
       <ColumnDefinition Width="2"/> 
       <ColumnDefinition Width="Auto"/> 
      </Grid.ColumnDefinitions> 
      <StackPanel Orientation="Vertical" Grid.Column="0"> 
       <TextBlock Text="Description:" Foreground="Gray" Margin="2,0,2,0" /> 
       <TextBlock Text="Item ID:" Foreground="Gray" Margin="2,0,2,0" /> 
      </StackPanel> 
      <StackPanel Orientation="Vertical" Grid.Column="2"> 
       <TextBlock Text="{Binding Descrip}" Margin="2,0,2,0" /> 
       <TextBlock Text="{Binding ItemID}" Margin="2,0,2,0" /> 
      </StackPanel> 
     </Grid> 
    </StackPanel> 
    <StackPanel Grid.Column="1"> 
     <Grid> 
      <Grid.ColumnDefinitions> 
       <ColumnDefinition Width="Auto"/> 
       <ColumnDefinition Width="2"/> 
       <ColumnDefinition Width="Auto"/> 
      </Grid.ColumnDefinitions> 
      <StackPanel Orientation="Vertical" Grid.Column="0"> 
       <TextBlock Text="Department ID:" Foreground="Gray" Margin="2,0,2,0" /> 
       <TextBlock Text="Class ID:" Foreground="Gray" Margin="2,0,2,0" /> 
      </StackPanel> 
      <StackPanel Orientation="Vertical" Grid.Column="2"> 
       <TextBlock Text="{Binding DepartmentID}" Margin="2,0,2,0" /> 
       <TextBlock Text="{Binding ClassID}" Margin="2,0,2,0" /> 
      </StackPanel> 
     </Grid> 
    </StackPanel> 
    <StackPanel Grid.Column="3" HorizontalAlignment="Right"> 
     <TextBlock Margin="2,0,0,2" FontSize="16" FontWeight="Bold" > 
      <Run Text="$" /> 
      <Run Text="{Binding Price}" /> 
     </TextBlock> 
    </StackPanel> 
</Grid> 

感謝

Answer 1

感謝@ gomi42這個工作;

<Style x:Key="autoBoxStyle" TargetType="ListBoxItem"> 
    <Setter Property="HorizontalContentAlignment" Value="Stretch" /> 
</Style>