![wpf treeview mvvm example wpf treeview mvvm example](http://i.stack.imgur.com/9Btd1.png)
Private static T FindAnchestor(DependencyObject current) where T : DependencyObjectĬurrent = VisualTreeHelper.GetParent(current) Private void tv_DragLeave(object sender, DragEventArgs e)
![wpf treeview mvvm example wpf treeview mvvm example](https://wpf-tutorial.com/Images/ArticleImages/1/chapters/treeview/treeview_multiple_templates.png)
reset background on leaved possible target TreeViewItem
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If (tvi != null) tvi.Background = Brushes.White reset background on target TreeViewItem (viewItemToInsert) Įlse if (!targetItem.Equals(draggedTVI.DataContext as ViewItem))ĭeleteViewNodeFromSource(vm.TreeViewSource, data)
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ViewItem viewItemToInsert = new ViewItem(data.ItemName) ViewItem data = (ViewItem)e.Data.GetData(typeof(ViewItem)) ViewItem targetItem = (e.OriginalSource as TextBlock)?.DataContext as ViewItem If (!e.Data.GetDataPresent(typeof(ViewItem))) return MainViewModel vm = (sender as TreeView).DataContext as MainViewModel Private void Tv_Drop(object sender, DragEventArgs e) If (tvi != null) tvi.Background = Brushes.MediumPurple TreeViewItem tvi = FindAnchestor((DependencyObject)e.OriginalSource) Private void tv_DragOver(object sender, DragEventArgs e) ViewItem dragData = draggedTVI.DataContext as ViewItem ĭragDrop.DoDragDrop(draggedTVI, dragData, DragDropEffects.Move) Private void tv_MouseMove(object sender, MouseEventArgs e) start Drag&Drop when mouse is moved and there's a saved TreeViewItem Private void PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) Private void AssociatedObject_PreviewMouseRightButtonDown(object sender, MouseButtonEventArgs e)ĭraggedTVI = FindAnchestor((DependencyObject)e.OriginalSource) ĭraggedTVI.Background = Brushes.MediumPurple Public class TreeViewDragDropBehavior : BehaviorĪssociatedObject.PreviewMouseLeftButtonDown += PreviewMouseLeftButtonDown ĪssociatedObject.MouseMove += tv_MouseMove ĪssociatedObject.DragOver += tv_DragOver ĪssociatedObject.DragLeave += tv_DragLeave ĪssociatedObject.PreviewMouseRightButtonDown += AssociatedObject_PreviewMouseRightButtonDown Only when I move mouse out of the window and move back into the window, I can do operation again, but only one operation and the same issue appears again. Not to show ContextMenu on other TreeViewItem or not to collapse a node. Clicks on any other places will not show the ContextMenu.Īnother issue I am facing is, after I right click on a TreeViewItem to show the ContextMenu, I cannot perform any other operations on the whole window. As you can see in the screeshot, I only want the ContextMenu to be displayed when mouse right clicks on the first level TreeViewItem(those in yellow). This defines a DataType and then the ItemSource as the collection within the DataType.Following MVVM, I have developed a TreeView and now I want mouse right click to show ContextMenu on certain TreeViewItem. A TreeView.Resources sits inside in which we define a HierarchicalTemplate. We define a TreeView & bind the ItemSource to our ItemsA. In the real world these lists are replaced with your queried data from the Database, Json, Xml etc:įinally our Xaml designer view. The ViewModel instantiates a collection of ItemA class objects, ItemA defines a collection of ItemB’s in the constructor & ItemB defines a list of ItemC. To acheive this we need to put our OOP hat on & build a hierarchy of classes to provide the TreeView with our data at run time. If you don’t know what to expect at run time then we can’t hard code the values, we need a dynamic TreeView! This is fine unless you have dynamic data. You could also bind these values to string property values exposed in your viewModel. TreeViewItems are nested within the TreeView & Headers are hardcoded. Hard coding your values is simple enough however I quickly learned that building a dynamic hierarchical TreeView was to be a little more complex!įirstly, here’s some simple hard coded Xaml: I got about using WPF’s TreeView control. I recently had a UI design which required the use of a tree view.