Public void get_children(TreeViewItem parent)ĭataRow rows = dt. SqlDataAdapter adapt = new SqlDataAdapter(sql, cnn) ĭataRow rows = dt.Select("fdr_parent_id = '0'")
The problem is that people often try to use it in the same way that one might code against the Windows Forms TreeView control. Many people try to use it, and find it to be exceedingly difficult. Create new WPF application and name it as TreeViewMVVMBinding. Background of TreeView The TreeView control in WPF has gained an undeserved bad reputation. Let’s take an example of populating employees’ details per position per department in hierarchical pattern. SqlCommand cmd = new SqlCommand(sql, cnn) Today, in this article, we will learn how to populate hierarchical data in TreeView in WPF using MVVM architecture. String sql = "SELECT * FROM tbl_report_folders ORDER BY fdr_parent_id ASC" Using (SqlConnection cnn = new SqlConnection(cnn_string)) The following example works for any TreeView, regardless of the underlying data model, and searches every TreeViewItem until the object is found. My usual approach, which is not quite classic MVVM, can be summarized as follows: A base class for a dialog ViewModel that exposes commands for commit and cancel actions, an event to lets the view know that a dialog is ready to be closed, and whatever else you will need in all of your dialogs. TreeViewItem item = (TreeViewItem)e.OriginalSource If you simply try to bind the SelectedItem property of the TreeView control to the SelectedItem source property of the view model in XAML using the ordinary binding markup extension syntax, Visual Studio will put a squiggly line under the property in the XAML view and tell you that the ‘SelectedItem’ property is read-only and cannot be. Public void tv_favorites_Expanded(object sender, RoutedEventArgs e) A TreeViewItem control is a HeaderedItemsControl that has a Header and an Items collection. Private string cnn_string = new cls_server().ConnectionString The TreeView control contains a hierarchy of TreeViewItem controls.
OK, well I have come up with a solution that seems to work, but I'm not sure if there is a better way.Īny suggestions would be welcome! public partial class MainWindow : Window 7 Answers Sorted by: 17 This is remarkably straightforward to do, once you know how. Can someone please provide me with some insight on how to accomplish this?
I have done a lot of reading about hierarchal data templates and observable collections but cannot seem to make them fit with my requirements (probably due to my lack of experience). The (Data)Model-View-ViewModel pattern is similar to the classic Model-View-Presenter, except you have a model tailor-made for the View, called the ViewModel. you set ItemTemplate for TreeViewItem, but you should set ItemTemplate for TreeView you addedIf I stored the data this way, I would need to add each folder to it's parent folder first (based on the ParentID), then add the reports to the correct folder (based on the FolderID).īeing fairly new to WPF and C# in general, I am not sure if this is the best way or if it would even work. I was thinking of having my database table structure as follows:
The application will not know how many levels there will be, only that there are 2 types of items, folders, and reports. This is where you would include the logic to handle ticking / unticking the. Create a common ViewModel base class to represent each node of the tree, with a collection of the same type to represent the nodes children.
The treeview needs to have multiple levels like the following: Like many other aspects of WPF development, this becomes much easier if you follow the MVVM pattern. This article takes that idea further, and shows how we can use a ViewModel to encapsulate application-specific logic related to the check state of items in the tree. You can also explore our WPF TreeView example to knows how to represents hierarchical data in a tree-like structure with expand and collapse node options.I am trying to populate a treeview from a database, but I am not sure the best way to do it. As explained in my ‘Simplifying the WPF TreeView by Using the ViewModel Pattern’ article, the TreeView was practically designed to be used in conjunction with a ViewModel. You can refer to our WPF TreeView feature tour page for its groundbreaking feature representations. Public class ViewModel : NotificationObject