移植WPF软件到uwp时碰到用作对话框的Window有多种处理选择。我个人认为最省事的是用ContentDialog模拟Window。
比如你想把上面这个WPF窗体弄到uwp里面去
1.修改ContentDialog的默认样式
新建一个模板化控件RoundCornerContentDialog
让它继承ContentDialog。
然后去Windows SDK里面翻默认样式（因为vs2015 update 1无法自动提取ContentDialog的默认样式到Xaml）。
我的电脑上默认样式在这个文件夹
C:\Program Files (x86)\Windows Kits\10\DesignTime\CommonConfiguration\Neutral\UAP\10.0.10586.0\Generic
找到之后打开刚才新建这个控件时的Themes\Generic.xaml
把ContentDialog的默认样式换进去。
由于要移植的对话框是圆角的，而且没有在底部放置额外的按钮，ContentDialog的样式需要修改。我把它改成了这样：
XAML
<Style TargetType="local:RoundCornerContentDialog" >
<Setter Property="Foreground" Value="{ThemeResource SystemControlPageTextBaseHighBrush}" />
<Setter Property="Background" Value="{ThemeResource SystemControlBackgroundChromeMediumLowBrush}" />
<Setter Property="HorizontalAlignment" Value="Center" />
<Setter Property="VerticalAlignment" Value="Top" />
<Setter Property="BorderThickness" Value="3" />
<Setter Property="IsTabStop" Value="False" />
<Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundAccentBrush}"/>
<Setter Property="MaxHeight" Value="{ThemeResource ContentDialogMaxHeight}" />
<Setter Property="MinHeight" Value="{ThemeResource ContentDialogMinHeight}" />
<Setter Property="MaxWidth" Value="{ThemeResource ContentDialogMaxWidth}" />
<Setter Property="MinWidth" Value="{ThemeResource ContentDialogMinWidth}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:RoundCornerContentDialog">
<Border x:Name="Container">
<Grid x:Name="LayoutRoot">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Border x:Name="BackgroundElement"
FlowDirection="{TemplateBinding FlowDirection}"
MaxWidth="{TemplateBinding MaxWidth}"
MaxHeight="{TemplateBinding MaxHeight}"
MinWidth="{TemplateBinding MinWidth}"
MinHeight="{TemplateBinding MinHeight}" >
<Grid x:Name="DialogSpace" VerticalAlignment="Stretch">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ScrollViewer x:Name="ContentScrollViewer"
HorizontalScrollBarVisibility="Disabled"
VerticalScrollBarVisibility="Disabled"
ZoomMode="Disabled"
IsTabStop="False">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ContentControl x:Name="Title"
Margin="{ThemeResource ContentDialogTitleMargin}"
Content="{TemplateBinding Title}"
ContentTemplate="{TemplateBinding TitleTemplate}"
FontSize="20"
FontFamily="XamlAutoFontFamily"
FontWeight="Normal"
Foreground="{TemplateBinding Foreground}"
HorizontalAlignment="Left"
VerticalAlignment="Top"
IsTabStop="False"
MaxHeight="{ThemeResource ContentDialogTitleMaxHeight}" >
<ContentControl.Template>
<ControlTemplate TargetType="ContentControl">
<ContentPresenter
Content="{TemplateBinding Content}"
MaxLines="2"
TextWrapping="Wrap"
ContentTemplate="{TemplateBinding ContentTemplate}"
Margin="{TemplateBinding Padding}"
ContentTransitions="{TemplateBinding ContentTransitions}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
</ControlTemplate>
</ContentControl.Template>
</ContentControl>
<ContentPresenter x:Name="Content"
Background="{TemplateBinding Background}"
BorderThickness="{TemplateBinding BorderThickness}"
BorderBrush="{ThemeResource ContentDialogBorderThemeBrush}"
CornerRadius="20"
ContentTemplate="{TemplateBinding ContentTemplate}"
Content="{TemplateBinding Content}" VerticalContentAlignment="Stretch"
FontSize="{ThemeResource ControlContentThemeFontSize}"
FontFamily="{ThemeResource ContentControlThemeFontFamily}"
Foreground="{TemplateBinding Foreground}"
Grid.Row="1"
TextWrapping="Wrap" />
</Grid>
</ScrollViewer>
<Grid x:Name="CommandSpace" Visibility="Collapsed" Grid.Row="1" HorizontalAlignment="Stretch" VerticalAlignment="Bottom">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Border x:Name="Button1Host"
Margin="{ThemeResource ContentDialogButton1HostMargin}"
MinWidth="{ThemeResource ContentDialogButtonMinWidth}"
MaxWidth="{ThemeResource ContentDialogButtonMaxWidth}"
Height="{ThemeResource ContentDialogButtonHeight}"
HorizontalAlignment="Stretch" />
<Border x:Name="Button2Host"
Margin="{ThemeResource ContentDialogButton2HostMargin}"
MinWidth="{ThemeResource ContentDialogButtonMinWidth}"
MaxWidth="{ThemeResource ContentDialogButtonMaxWidth}"
Height="{ThemeResource ContentDialogButtonHeight}"
Grid.Column="1"
HorizontalAlignment="Stretch" />
</Grid>
</Grid>
</Border>
</Grid>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
2.添加DragMove方法
需要移植的那个WPF窗口是可以在空白处进行拖动的。
通过输入指针的事件收集信息，对ContentDialog的Margin属性进行更改达到模拟拖动的效果。
子类调用DragMove方法启用拖动。
下面是VB代码示例。需要其它语言示例的话可以用SharpDevelop转换。
VB
Protected Sub DragMove(ptr As Pointer)
Pressed = True
CapturePointer(ptr)
End Sub Dim Pressed As Boolean
Dim pos As Point
Private Sub RoundCornerContentDialog_PointerMoved(sender As Object, e As PointerRoutedEventArgs) Handles Me.PointerMoved
If Pressed Then
Dim pt = e.GetCurrentPoint(Me).Position
Dim marg = Margin
Dim ofsx = pt.X - pos.X
Dim ofsy = pt.Y - pos.Y
marg.Left += ofsx
marg.Right -= ofsx
marg.Top += ofsy
marg.Bottom -= ofsy
Margin = marg
End If
End Sub Private Sub RoundCornerContentDialog_PointerReleased(sender As Object, e As PointerRoutedEventArgs) Handles Me.PointerReleased
Pressed = False
ReleasePointerCapture(e.Pointer)
End Sub Private Sub RoundCornerContentDialog_PointerPressed(sender As Object, e As PointerRoutedEventArgs) Handles Me.PointerPressed
pos = e.GetCurrentPoint(Me).Position
End Sub
3.把对话框内容加进去
新建一个ContentDialog,并把Xaml根节点的名称改为刚才建立的local:RoundCornerContentDialog,还要在相应的类里面把基类也改成RoundCornerContentDialog。
注意，加入内容时要考虑照顾小屏幕设备和低性能设备。
我把布局改了一下，按钮的视觉效果也去除了。
4.在合适的位置调用DragMove
在你认为表示非客户区中可拖动部分的控件的PointerPressed调用DragMove
VB
Private Sub RectDrag_PointerPressed(sender As Object, e As PointerRoutedEventArgs) Handles RectDrag.PointerPressed
DragMove(e.Pointer)
End Sub
5.其它功能的模拟
有些对话框需要拖动改变大小之类复杂的功能。这个可以仿照WPF的自定义处理非客户区碰撞检测消息进行编写。
以后我遇到需要实现这个功能的时候会补上这里的代码。