Drag-Drop Reorder Multiple Selection Issue

[Daniel]

Hello,

I am having an issue with reordering multiple selected items in a RadListBox. I am trying to select multiple items in a RadListBox, and drag them within the same RadListBox to reorder them. However, it doesn't always work. When I start to drag, sometimes I will be able to reorder the items (cursor indicator and drop visual indicator in the RadListBox show normally), and sometimes it won't. The drag visual always works normally, but it looks like AllowDrop is immediately false sometimes (not sure if that is what is actually happening, but it's the best way I can describe it). I have a test RadListBox for theme visual feedback and testing, and the behavior is happening there. Here is the code I am using:

<telerik:RadListBox SelectionMode="Extended">
    <telerik:RadListBoxItem Content="Item 1"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 2"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 3"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 4"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 5"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 6"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 7"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBoxItem Content="Item 8"
                    Style="{DynamicResource ReorderableListItemStyle}"/>
    <telerik:RadListBox.DragDropBehavior>
        <telerik:ListBoxDragDropBehavior/>
    </telerik:RadListBox.DragDropBehavior>
</telerik:RadListBox>

 

And here is the code for ReorderableListItemStyle:

<Style x:Key="ReorderableListItemStyle"
    TargetType="telerik:RadListBoxItem"
    BasedOn="{StaticResource RadListBoxItemStyle}">
    <Setter Property="telerik:DragDropManager.AllowCapturedDrag" Value="True" />
</Style>

 

Is there something I am missing? I am using Telerik WPF R3 2020.

[Dinko | Tech Support Engineer]

Hi Daniel,

Thank you for the provided code snippet.

I have run a few tests, but I wasn't able to observe the described behavior. I have used the code snippet from your post for testing purposes. Is it possible to create a video that shows the steps and this behavior? This way, I can try to follow them on my side to reproduce it. 

I am looking forward to your reply.

Regards,
Dinko
Progress Telerik

[Daniel]

Hello Dinko,

Thanks for replying. I have included a link to a video below. It is the same RadListBox mentioned above, and I am using Ctrl + Click to select multiple items, then trying to drag them to reorder. The color effects around the cursor are from the recording software. Let me know if you need anything else from me.

https://www.dropbox.com/s/bqp71cwxs0wv3nv/ListBoxForTelerik.mp4?dl=0

[Daniel]

We found the issue. It turns out that when you select multiple items, Visual Studio places the debugger toolbar on the drag visual, and if you happen to mouse over that during the drag, it causes the issue mentioned.

[Dinko | Tech Support Engineer]

Hello Daniel,

I am happy to hear that you have found a solution for your case, and thank you for sharing it. If you have any other questions, you can open a new thread with your questions inside, and we will be happy to help.

Regards,
Dinko
Progress Telerik