Change grid Column width inside the listbox on Usercontrol at Mainpage code behind - windows-phone-7

Question

I have an ListBox UserControl and there is a grid control in the DataTemplate. I used the MVVM to bind the data. For Orientation change, I am able to change the wide of the ListBox, but I don't find the solution to change the grid column width inside the listbox. Would you help me how to do it or provide a example or link to me. Thanks in advance.
There is my UserControl.xaml
<UserControl x:Class="CMSPhoneApp.QueueListControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
d:DesignHeight="480" d:DesignWidth="480"
xmlns:local="clr-namespace:CMSPhoneApp" >
<UserControl.Resources>
<local:VisibilityConverter x:Key="VisibilityConverter"/>
<local:ColumSpanConverter x:Key="ColumSpanConverter"/>
</UserControl.Resources>
<ListBox x:Name="lst" HorizontalAlignment="Left" Margin="6,6,0,0" VerticalAlignment="Top" Width="400"
ItemsSource="{Binding Path=MyQueue}"
SelectedItem="{Binding Path=CurrentQueue, Mode=TwoWay}" Height="380" >
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderThickness="1,1,1,1" BorderBrush="Blue">
<Grid x:Name="grd" Width="auto" HorizontalAlignment="Stretch" >
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="35" />
<ColumnDefinition Width="250"/>
<ColumnDefinition Width="125" />
</Grid.ColumnDefinitions>
<Image Source="{Binding Type}" Grid.Row="0" Grid.Column="0"/>
<TextBlock Grid.Row="0" Grid.Column="1" Grid.ColumnSpan= "{Binding isSpan, Converter={StaticResource ColumSpanConverter}}" Text="{Binding summary}" TextWrapping="Wrap"
Style="{StaticResource PhoneTextAccentStyle}" />
<Button x:Name="btnAction" Grid.Row="0" Grid.Column="3" ClickMode="Press" Click="btnAction_Click" Style="{StaticResource ButtonStyle1}"
Visibility="{Binding isVisibility, Converter={StaticResource VisibilityConverter}}"
Tag="{Binding callNumber}">
<Button.Content>
<TextBlock Width="85" Height="70" Text="{Binding ActionCaption}"
Style="{StaticResource LabelStyle_20}" />
</Button.Content>
</Button>
</Grid>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The OrientationChange code:
private void TestPage_OrientationChanged(
object sender, OrientationChangedEventArgs e)
{
ListBox lstControl = lst.lst;
Grid g = lstControl.ItemContainerGenerator.ContainerFromIndex(0) as Grid;
if (e.Orientation.ToString().Contains("Portrait"))
lst.lst.Height = 400;
else
lst.lst.Height = 120;
}

Answer 1

Instead of absolute values for the column width, you should use percentage or "Star Sizing". Star sizing allows the width of a column (or height of a row) to grow or shrink as the available size changes.
Here is an example to use:
<Grid.ColumnDefinitions>
<ColumnDefinition Width=".1*" />
<ColumnDefinition Width=".6*"/>
<ColumnDefinition Width=".3*" />
</Grid.ColumnDefinitions>
Along with this you should remove the Width value of the ListBox and allow it to fill all available space.