4/29/2023 0 Comments Asp.net treeview examples![]() ![]() But I cannot find out the reason for this myself. Protected void tvw_SelectedNodeChanged(object snd, EventArgs evt)įor (int i = 0 i < i++)ĭear community, I believe that this minimal example shows my problem very clearly. Private Table createTable(Control ctl_l, Control ctl_r) ![]() Trv.SelectedNodeChanged += new EventHandler(tvw_SelectedNodeChanged) Protected override void CreateChildControls() Second, 'subgroup1 and subgroup1' may be is a semantic error. Public virtual ControlCollection /*TreePageCollection*/ PagesĬol_Pages = new ControlCollection (this) Private ControlCollection col_Pages = null Public class TreePageView : CompositeControl Public class TreePage : Panel, INamingContainerĪnd here is the code for TreePageView.cs: using System Here is the code for TreePage.cs: using System However, here is the code for TreePageNode.cs: using System When you then select an arbitrary node, you get this exception: When the variable crash is set to true, another node called "Evil node" is added to the tree in the Page_LoadComplete event. When the variable crash is set to false, you can select any node and on the right you see "This is an Employer" or "This is a Car", respectively. When this variable is set to true, the application exits with an exception described below whenever an arbitrary node in the tree is selected. Here you can see the member variable "crash". Protected void Page_LoadComplete(object snd, EventArgs evt) Protected void Page_Load(object snd, EventArgs evt) Private static bool crash = true // if this is true, we crash when a node is selected Here is the code behind for this page: using System The Pages section contains one page for the type "emp" and one page for the type "car". The persons belong to the type "emp", which means "employer", while the cars belong to the type "car", which means "car". There are some persons and some cars in the tree. The Nodes section contains the tree nodes. Here we have such a TreePageView, with a "Nodes" section and a "Pages" section. ![]() I want to declare this with the following markup: This control should be called a "TreePageView" the tree nodes are called "TreePageNode" the pages are called "TreePage". For each type there is a corresponding "page", which should be displayed in the MultiView when a node with the corresponding I want one control that has a TreeView to the left and a MultiView to the right. Iīelieve that it could not be much smaller. I swear, I did a really hard work to extract the problem from my real-life project and reduce it to a minimal example. I already made experience with some custom controls, but this one has some specific difficulties. It's supported by Internet Explorer version 5.0 (or higher) and Netscape version 6.0 (or higher) and uses XmlHttp.I need help with a custom control. The dynamical loading of the TreeView control is based on the new Client Callback feature, which I'll explain later in the book. You'll better understand this example by using the debugger just place a breakpoint in the LoadChildNodes method. By using the DirectoryInfo class in the System.IO namespace, you can read the subfolders and pass them as subnodes to the TreeView control. In this case, the result is the current path. The latter returns a list of all values from the current node up to the root. When data-bound to these types of data sources, RadTreeView automatically creates the node hierarchy. These include SiteMapDataSource and XmlDataSource. Some of the declarative data sources are inherently hierarchical. This method queries the value of the selected node or, if available, of the ValuePath property. RadTreeView supports binding to various types of data sources, including declarative datasources. If not, those are loaded using the LoadChildNodes method. Within the TreeNodePopulate event the current node is checked as to whether it already contains subnodes. Caching also belongs to the functions set.įigure 3-21: Nested directories are populated dynamically if you click the parent.Īctually this isn't a zero-code scenario, but it's just a tiny and understandable piece of code that is needed for this example. If the XML file is displayed without transformation, you even have write access. For example, you have the option to assign a schema file (XSD file), a transformation file (XSL file) or an XPath expression to the corresponding properties. Then hit F5 and see what's happening in your browser window.įigure 3-19 shows the result, which looks pretty professional, but I guess you may have expected the data in a different shape.Īnd of course, the XmlDataSource control offers many more features than you've seen so far. If desired, you can apply one of the built-in format templates I explained previously. Select the books.xml file as the new XmlDataSource. Now choose the Connect To DataSource command in the Task List. After creating the file, you can place a new TreeView control on your page. ![]()
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