Drag&drop doesn't work in wpf in rhino

Rhino Developer
,
1

Hi
I use a wpf sample to create my own plugin for rhino, the function is a wpf contains a treeview, this treeview load some gh files in a folder. I would like to drag the gh file into active grasshopper file, but when i drag, it seems doesn’t work. Belows are dragleave event, I think the code should be ok, the reason is probably related to my sample, the sample i used is SampleCSwpf which may have some special setting. i use the I am a new developer. Can anybody help? Thank you very much!

private void treeView1_DragLeave(object sender, DragEventArgs e)
{
  string file = "C:\\Users\\DIY\\Desktop\\Project\\Buildings" + treeView1.SelectedValue.ToString();
  DataObject dataObject = new DataObject(DataFormats.FileDrop, new string[] { file });
  DragDropEffects finalDropEffect = DragDrop.DoDragDrop(treeView1, dataObject, DragDropEffects.Move);
}
2

Hi @z112 ,
You should be using using the MouseLeftButtonDown or PreviewMouseLeftButtonDown event to start the drag-and-drop operation.

private void treeView1_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    TreeViewItem treeViewItem = FindAncestor<TreeViewItem>((DependencyObject)e.OriginalSource);

    if (treeViewItem != null)
    {
        string file = "C:\\whatever" + treeView1.SelectedValue.ToString();
        DataObject dataObject = new DataObject(DataFormats.FileDrop, new string[] { file });
        DragDrop.DoDragDrop(treeView1, dataObject, DragDropEffects.Move);
    }
}

// Helper to search up the VisualTree
private static T FindAncestor<T>(DependencyObject current)
    where T : DependencyObject
{
    do
    {
        if (current is T)
        {
            return (T)current;
        }
        current = VisualTreeHelper.GetParent(current);
    }
    while (current != null);
    return null;
}

The target application must also be configured to accept the dragged items.
I hope that sparks some inspiration.

Farouk

3

Hi Farouk,

Thank you for your reply. I tried Winform and it works. So i changed my plugin to Winform. I’ll try your answer later and back to you then.

Wei