How to Apply Styles at runtime in Childwindow in silverlight?

I am not able to apply style at runtime on child window.I have created two styles one with chrome and one without chrome. What i wanted to do is on mediaplayer fullscreen mode disable the dragging of child window and on press on escape button(norma开发者_运维知识库l mode) enable dragging of child window. My code looks like this :

void Content_FullScreenChanged(object sender, EventArgs e)
{

        if (App.Current.Host.Content.IsFullScreen)
        {

            ObjChildMediaPlayer.Style  = Application.Current.Resources["TestStyle"] as Style;
        }
        else
        {

            ObjChildMediaPlayer.Style  = Application.Current.Resources["TestBasicStyle"] as Style;                

        }

        ObjChildMediaPlayer.UpdateLayout();
    } 

On full screen dragging is disabling but when i press escape button it does not drag. I want the child window to be dragging in normal mode.

TestStyle :

<Style x:Key ="TestStyle" TargetType="controls:ChildWindow">
    <Setter Property="IsTabStop" Value="True" />
    <Setter Property="TabNavigation" Value="Cycle" />
    <Setter Property="HorizontalAlignment" Value="Center" />
    <Setter Property="VerticalAlignment" Value="Center" />
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="BorderBrush">
        <Setter.Value>
            <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
                <GradientStop Color="#FFA3AEB9" Offset="0" />
                <GradientStop Color="#FF8399A9" Offset="0.375" />
                <GradientStop Color="#FF718597" Offset="0.375" />
                <GradientStop Color="#FF617584" Offset="1" />
            </LinearGradientBrush>
        </Setter.Value>
    </Setter>
    <Setter Property="OverlayBrush">
        <Setter.Value>
            <SolidColorBrush Color="#7F000000" />
        </Setter.Value>
    </Setter>
    <Setter Property="OverlayOpacity" Value="1" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="controls:ChildWindow">
                <Grid x:Name="Root">
                    <Grid.Resources>
                        <Style x:Key="ButtonStyle" TargetType="Button">
                            <Setter Property="Background" Value="#FF1F3B53" />
                            <Setter Property="Foreground" Value="#FF000000" />
                            <Setter Property="Padding" Value="3" />
                            <Setter Property="BorderThickness" Value="1" />
                            <Setter Property="BorderBrush">
                                <Setter.Value>
                                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                        <GradientStop Color="#FFA3AEB9" Offset="0" />
                                        <GradientStop Color="#FF8399A9" Offset="0.375" />
                                        <GradientStop Color="#FF718597" Offset="0.375" />
                                        <GradientStop Color="#FF617584" Offset="1" />
                                    </LinearGradientBrush>
                                </Setter.Value>
                            </Setter>
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="Button">
                                        <Grid HorizontalAlignment="Center" VerticalAlignment="Center" Width="15" Height="14" Background="#02FFFFFF" x:Name="grid">
                                            <vsm:VisualStateManager.VisualStateGroups>
                                                <vsm:VisualStateGroup x:Name="CommonStates">
                                                    <vsm:VisualState x:Name="Normal" />
                                                    <vsm:VisualState x:Name="MouseOver">
                                                        <Storyboard>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="X_Fuzz2" Storyboard.TargetProperty="Visibility">
                                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="X_Fuzz1" Storyboard.TargetProperty="Visibility">
                                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="X_Fuzz0" Storyboard.TargetProperty="Visibility">
                                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <DoubleAnimation Duration="0" Storyboard.TargetName="X" Storyboard.TargetProperty="Opacity" To="0.95" />
                                                        </Storyboard>
                                                    </vsm:VisualState>
                                                    <vsm:VisualState x:Name="Pressed">
                                                        <Storyboard>
                                                            <DoubleAnimation Duration="0" Storyboard.TargetName="X" Storyboard.TargetProperty="Opacity" To="0.85" />
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="X_Fuzz2" Storyboard.TargetProperty="Visibility">
                                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="X_Fuzz1" Storyboard.TargetProperty="Visibility">
                                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="X_Fuzz0" Storyboard.TargetProperty="Visibility">
                                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Visible" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                        </Storyboard>
                                                    </vsm:VisualState>
                                                    <vsm:VisualState x:Name="Disabled">
                                                        <Storyboard>
                                                            <DoubleAnimation Duration="0" Storyboard.TargetName="X" Storyboard.TargetProperty="Opacity" To="0.5" />
                                                        </Storyboard>
                                                    </vsm:VisualState>
                                                </vsm:VisualStateGroup>
                                            </vsm:VisualStateManager.VisualStateGroups>
                                            <Path HorizontalAlignment="Center" Margin="0,-1,0,0" Width="9" Fill="#14C51900" Stretch="Fill" Data="F1 M 6.742676,3.852539 L 9.110840,1.559570 L 8.910645,0.500000 L 6.838379,0.500000 L 4.902832,2.435547 L 2.967285,0.500000 L 0.895020,0.500000 L 0.694824,1.559570 L 3.062988,3.852539 L 0.527832,6.351563 L 0.689941,7.600586 L 2.967285,7.600586 L 4.897949,5.575195 L 6.854004,7.600586 L 9.115723,7.600586 L 9.277832,6.351563 L 6.742676,3.852539 Z" x:Name="X_Fuzz2" Stroke="#14C51900" Height="8" VerticalAlignment="Center" Opacity="1" RenderTransformOrigin="0.5,0.5" Visibility="Collapsed">
                                                <Path.RenderTransform>
                                                    <TransformGroup>
                                                        <ScaleTransform ScaleX="1.3" ScaleY="1.3" />
                                                    </TransformGroup>
                                                </Path.RenderTransform>
                                            </Path>
                                            <Path HorizontalAlignment="Center" Margin="0,-1,0,0" Width="9" Fill="#1EC51900" Stretch="Fill" Data="F1 M 6.742676,3.852539 L 9.110840,1.559570 L 8.910645,0.500000 L 6.838379,0.500000 L 4.902832,2.435547 L 2.967285,0.500000 L 0.895020,0.500000 L 0.694824,1.559570 L 3.062988,3.852539 L 0.527832,6.351563 L 0.689941,7.600586 L 2.967285,7.600586 L 4.897949,5.575195 L 6.854004,7.600586 L 9.115723,7.600586 L 9.277832,6.351563 L 6.742676,3.852539 Z" x:Name="X_Fuzz1" Stroke="#1EC51900" Height="8" VerticalAlignment="Center" Opacity="1" RenderTransformOrigin="0.5,0.5" Visibility="Collapsed">
                                                <Path.RenderTransform>
                                                    <TransformGroup>
                                                        <ScaleTransform ScaleX="1.1" ScaleY="1.1" />
                                                    </TransformGroup>
                                                </Path.RenderTransform>
                                            </Path>
                                            <Path HorizontalAlignment="Center" Margin="0,-1,0,0" Width="9" Fill="#FFC51900" Stretch="Fill" Data="F1 M 6.742676,3.852539 L 9.110840,1.559570 L 8.910645,0.500000 L 6.838379,0.500000 L 4.902832,2.435547 L 2.967285,0.500000 L 0.895020,0.500000 L 0.694824,1.559570 L 3.062988,3.852539 L 0.527832,6.351563 L 0.689941,7.600586 L 2.967285,7.600586 L 4.897949,5.575195 L 6.854004,7.600586 L 9.115723,7.600586 L 9.277832,6.351563 L 6.742676,3.852539 Z" x:Name="X_Fuzz0" Stroke="#FFC51900" Height="8" VerticalAlignment="Center" Opacity="1" Visibility="Collapsed" />
                                            <Path HorizontalAlignment="Center" Margin="0,-1,0,0" Width="9" Fill="#FFFFFFFF" Stretch="Fill" Data="F1 M 6.742676,3.852539 L 9.110840,1.559570 L 8.910645,0.500000 L 6.838379,0.500000 L 4.902832,2.435547 L 2.967285,0.500000 L 0.895020,0.500000 L 0.694824,1.559570 L 3.062988,3.852539 L 0.527832,6.351563 L 0.689941,7.600586 L 2.967285,7.600586 L 4.897949,5.575195 L 6.854004,7.600586 L 9.115723,7.600586 L 9.277832,6.351563 L 6.742676,3.852539 Z" x:Name="X" Height="8" VerticalAlignment="Center" Opacity="0.7">
                                                <Path.Stroke>
                                                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                        <GradientStop Color="#FF313131" Offset="1" />
                                                        <GradientStop Color="#FF8E9092" Offset="0" />
                                                    </LinearGradientBrush>
                                                </Path.Stroke>
                                            </Path>
                                        </Grid>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </Grid.Resources>
                    <vsm:VisualStateManager.VisualStateGroups>
                        <vsm:VisualStateGroup x:Name="WindowStates">
                            <vsm:VisualState x:Name="Open">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames BeginTime="0" Storyboard.TargetName="Overlay" Storyboard.TargetProperty="Opacity">
                                        <EasingDoubleKeyFrame KeyTime="0" Value="0" />
                                        <EasingDoubleKeyFrame KeyTime="00:00:00.3" Value="1" />
                                    </DoubleAnimationUsingKeyFrames>
                                    <DoubleAnimationUsingKeyFrames BeginTime="0" Storyboard.TargetName="ContentRoot" Storyboard.TargetProperty="(RenderTransform).(Children)[0].ScaleX">
                                        <SplineDoubleKeyFrame KeyTime="0" Value="0" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="0" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.4" Value="1" />
                                        <SplineDoubleKeyFrame KeySpline="0,0,0.5,1" KeyTime="00:00:00.45" Value="1.05" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.55" Value="1" />
                                    </DoubleAnimationUsingKeyFrames>
                                    <DoubleAnimationUsingKeyFrames BeginTime="0" Storyboard.TargetName="ContentRoot" Storyboard.TargetProperty="(RenderTransform).(Children)[0].ScaleY">
                                        <SplineDoubleKeyFrame KeyTime="0" Value="0" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="0" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.4" Value="1" />
                                        <SplineDoubleKeyFrame KeySpline="0,0,0.5,1" KeyTime="00:00:00.45" Value="1.05" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.55" Value="1" />
                                    </DoubleAnimationUsingKeyFrames>
                                </Storyboard>
                            </vsm:VisualState>
                            <vsm:VisualState x:Name="Closed">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames BeginTime="0" Storyboard.TargetName="Overlay" Storyboard.TargetProperty="Opacity">
                                        <EasingDoubleKeyFrame KeyTime="0" Value="1" />
                                        <EasingDoubleKeyFrame KeyTime="00:00:00.3" Value="0" />
                                    </DoubleAnimationUsingKeyFrames>
                                    <DoubleAnimationUsingKeyFrames BeginTime="0" Storyboard.TargetName="ContentRoot" Storyboard.TargetProperty="(RenderTransform).(Children)[0].ScaleX">
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.2" Value="1" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="1.05" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.45" Value="0" />
                                    </DoubleAnimationUsingKeyFrames>
                                    <DoubleAnimationUsingKeyFrames BeginTime="0" Storyboard.TargetName="ContentRoot" Storyboard.TargetProperty="(RenderTransform).(Children)[0].ScaleY">
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.2" Value="1" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="1.05" />
                                        <SplineDoubleKeyFrame KeyTime="00:00:00.45" Value="0" />
                                    </DoubleAnimationUsingKeyFrames>
                                </Storyboard>
                            </vsm:VisualState>
                        </vsm:VisualStateGroup>
                    </vsm:VisualStateManager.VisualStateGroups>
                    <Grid x:Name="Overlay" HorizontalAlignment="Stretch" VerticalAlignment="Top" Margin="0" Background="{TemplateBinding OverlayBrush}" Opacity="{TemplateBinding OverlayOpacity}" />
                    <Grid x:Name="ContentRoot" HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}" RenderTransformOrigin="0.5,0.5" Height="{TemplateBinding Height}" Width="{TemplateBinding Width}">
                        <Grid.RenderTransform>
                            <TransformGroup>
                                <ScaleTransform />
                                <SkewTransform />
                                <RotateTransform />
                                <TranslateTransform />
                            </TransformGroup>
                        </Grid.RenderTransform>
                        <Border BorderThickness="1" CornerRadius="2" BorderBrush="#14000000" Background="#14000000" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="-1" />
                        <Border BorderThickness="1" CornerRadius="2.25" BorderBrush="#0F000000" Background="#0F000000" HorizontalAlignment="Stretch" Margin="-2" VerticalAlignment="Stretch" />
                        <Border BorderThickness="1" CornerRadius="2.5" BorderBrush="#0C000000" Background="#0C000000" HorizontalAlignment="Stretch" Margin="-3" VerticalAlignment="Stretch" />
                        <Border BorderThickness="1" CornerRadius="2.75" BorderBrush="#0A000000" Background="#0A000000" HorizontalAlignment="Stretch" Margin="-4" VerticalAlignment="Stretch" />
                        <Border Background="#FFFFFFFF" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" CornerRadius="2">
                            <Border CornerRadius="1.5" Margin="1">
                                <Border.Background>
                                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                        <GradientStop Color="#FFE5E8EB" Offset="1" />
                                        <GradientStop Color="#FFF6F8F9" Offset="0" />
                                    </LinearGradientBrush>
                                </Border.Background>
                                <Grid IsHitTestVisible="True" >
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="Auto" />
                                        <RowDefinition />
                                    </Grid.RowDefinitions>
                                    <Border x:Name="Chrome" Width="Auto" BorderBrush="#FFFFFFFF" BorderThickness="0,0,0,1">
                                        <Border.Background>
                                            <LinearGradientBrush EndPoint="0.5,0.528" StartPoint="0.5,0">
                                                <GradientStop Color="#FFE5E8EB" Offset="1" />
                                                <GradientStop Color="#FFFEFEFE" Offset="0" />
                                            </LinearGradientBrush>
                                        </Border.Background>
                                        <Grid Height="Auto" Width="Auto">
                                            <Grid.ColumnDefinitions>
                                                <ColumnDefinition />
                                                <ColumnDefinition Width="30" />
                                            </Grid.ColumnDefinitions>

Other style does not have chrome rest everything is same.