Drag and Drop not working on GridView

Question

I am trying to implement similar functionality in my code: http://www.codeproject.com/Articles/536519/Extending-GridView-with-Drag-and-Drop-for-Grouping

I went ahead and copied the relevant files from that project (Customized.xaml, Customized.xaml.cs, Grouped.xaml, Grouped.xaml.cs and GridViewEx.cs) to my project. I have renamed the necessary items for it to compile, however I am facing a problem with GridView not scrolling and the reordering of items is not working on touchscreen. (Oddly enough, I can still move the items around with the mouse, however the Drop does not register consistently). It seems like there is some kind of a layout problem or there must be a reason for scrolling not working at all, drag and drop only working with a mouse, and drop functionality working about 50% of the time with the mouse. Any advice?

Answer 1

I don't know if you have figured out your problem yet or now, but I ended up figuring out why I was having this problem. It turs out that you must import not just GridViewEx.cs and the related Grouped.xaml and Grouped.xaml.cs, but also the stuff from "generic.xaml".

<Style TargetType="local:GridViewEx">
    <Setter Property="Padding" Value="0,0,0,10" />
    <Setter Property="IsTabStop" Value="False" />
    <Setter Property="TabNavigation" Value="Once" />
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Disabled"/>
    <Setter Property="ScrollViewer.HorizontalScrollMode" Value="Enabled" />
    <Setter Property="ScrollViewer.IsHorizontalRailEnabled" Value="False" />
    <Setter Property="ScrollViewer.VerticalScrollMode" Value="Disabled" />
    <Setter Property="ScrollViewer.IsVerticalRailEnabled" Value="False" />
    <Setter Property="ScrollViewer.ZoomMode" Value="Disabled" />
    <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
    <Setter Property="ScrollViewer.BringIntoViewOnFocusChange" Value="True" />
    <Setter Property="IsSwipeEnabled" Value="True" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="local:GridViewEx">
                <Border BorderBrush="{TemplateBinding BorderBrush}"
                        Background="{TemplateBinding Background}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                    <ScrollViewer x:Name="ScrollViewer"
                                        TabNavigation="{TemplateBinding TabNavigation}"
                                        HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
                                        HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
                                        IsHorizontalScrollChainingEnabled="{TemplateBinding ScrollViewer.IsHorizontalScrollChainingEnabled}"
                                        VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
                                        VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
                                        IsVerticalScrollChainingEnabled="{TemplateBinding ScrollViewer.IsVerticalScrollChainingEnabled}"
                                        IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
                                        IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
                                        ZoomMode="{TemplateBinding ScrollViewer.ZoomMode}"
                                        IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
                                        BringIntoViewOnFocusChange="{TemplateBinding ScrollViewer.BringIntoViewOnFocusChange}">
                        <StackPanel Orientation="Horizontal">
                            <Border Width="60" x:Name="NewGroupPlaceHolderFirst" 
                                    Background="Transparent" Padding="{TemplateBinding Padding}" 
                                    Visibility="{Binding AllowNewGroup, Converter={StaticResource VisibilityConverter}, RelativeSource={RelativeSource TemplatedParent}}"/>
                            <ItemsPresenter 
                                Header="{TemplateBinding Header}" 
                                HeaderTemplate="{TemplateBinding HeaderTemplate}"
                                HeaderTransitions="{TemplateBinding HeaderTransitions}"
                                Padding="{TemplateBinding Padding}"/>
                            <Border Width="60" x:Name="NewGroupPlaceHolderLast" 
                                    Background="Transparent" Padding="{TemplateBinding Padding}" 
                                    Visibility="{Binding AllowNewGroup, Converter={StaticResource VisibilityConverter}, RelativeSource={RelativeSource TemplatedParent}}"/>
                        </StackPanel>
                    </ScrollViewer>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

After I linked this style to my Grouped.xaml, it worked as intended. Hope this helps.