Hello, i want use the treeview, i have many elements. so it stretch if i expand it over the screen, and this is not fine :)
so i want the treeview in the dropdown list. but it doestn work. it looks horrible. Have someone a idea or a soution. thank you.
this is my code. and i need a treeview. because i have expand items.
<TelerikDropDownList Data="@FlatData" @bind-Value="SelectedItemText" >Hello,
We recently upgraded to Telerik v7.0 for our controls and since then expanding a single item always expands all items. Has anyone else run into this or does anyone know a workaround?
Is there a way to use a Switch control instead of checkbox in a TreeView? I am able to use ItemTemplate to insert a switch next to the checkbox but I need to replace the checkbox and have the switch use CheckChildren and CheckParents.
Any ideas?
Thanks!
<TelerikTreeView OnItemRender="@OnItemRender" CheckBoxMode="TreeViewCheckBoxMode.Multiple" CheckChildren="true" CheckParents="true" Data="@FlatData" @bind-ExpandedItems="@ExpandedItems">
<TreeViewBindings>
<TreeViewBinding TextField="Text" IdField="Id" ParentIdField="ParentId" ItemsField="Text" HasChildrenField="HasChildren" IconField="Icon">
<ItemTemplate>
@{var treeItem = (TreeItem)context; }
<div class="treeview-item">
<TelerikSwitch @bind-Value="treeItem.IsChecked" />
<span>@treeItem.Text</span>
</div>
</ItemTemplate>
</TreeViewBinding>
</TreeViewBindings>
</TelerikTreeView>
Microsoft.JSInterop.JSException: Cannot read properties of null (reading 'addEventListener') TypeError: Cannot read properties of null (reading 'addEventListener') at c.bindEvents (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1282242) at new c (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1282116) at e.initComponent (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1085487) at e.initTreeView (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1279920) at https://0.0.0.0/_framework/blazor.webview.js:1:3337 at new Promise (<anonymous>) at beginInvokeJSFromDotNet (https://0.0.0.0/_framework/blazor.webview.js:1:3311) at https://0.0.0.0/_framework/blazor.webview.js:1:42795 at EventTarget.<anonymous> (<anonymous>:7:62) at EmbeddedBrowserWebView.<anonymous> (<anonymous>:1:40673)
at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
at Microsoft.JSInterop.JSRuntimeExtensions.InvokeVoidAsync(IJSRuntime jsRuntime, String identifier, Object[] args)
at Telerik.Blazor.Components.TelerikTreeView.InitTreeView()
at Telerik.Blazor.Components.TelerikTreeView.OnAfterRenderAsync(Boolean firstRender)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)
Microsoft.JSInterop.JSException: Cannot read properties of null (reading 'addEventListener') TypeError: Cannot read properties of null (reading 'addEventListener') at c.bindEvents (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1282242) at new c (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1282116) at e.initComponent (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1085487) at e.initTreeView (https://0.0.0.0/_content/Telerik.UI.for.Blazor/js/telerik-blazor.js:50:1279920) at https://0.0.0.0/_framework/blazor.webview.js:1:3337 at new Promise (<anonymous>) at beginInvokeJSFromDotNet (https://0.0.0.0/_framework/blazor.webview.js:1:3311) at https://0.0.0.0/_framework/blazor.webview.js:1:42795 at EventTarget.<anonymous> (<anonymous>:7:62) at EmbeddedBrowserWebView.<anonymous> (<anonymous>:1:40673)
at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
at Microsoft.JSInterop.JSRuntimeExtensions.InvokeVoidAsync(IJSRuntime jsRuntime, String identifier, Object[] args)
at Telerik.Blazor.Components.TelerikTreeView.InitTreeView()
at Telerik.Blazor.Components.TelerikTreeView.OnAfterRenderAsync(Boolean firstRender)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)
Hi, I am trying to implement Drag and Drop on the Blazor Treeview component. I am using version 4.4.0 and have been referencing this documentation: https://docs.telerik.com/blazor-ui/components/treeview/drag-drop#ondragstart-event
So far
The event "OnDragStart" does not exist,
The class "TreeViewDragStartEventArgs" does not exist.
Your documentation never seems to list when functionality is available so I have no idea if it is the version I am using, something I have done, or your components.
Would love some help clearing this up.
Hi,
I have a TreeView where the initial values are set programmatically.
When all the child nodes are checked the parent node should be checked as well. But it isn't:
https://blazorrepl.telerik.com/GIOLlWks03IKIiiZ31
Is there any solution for that?
Best regards,
Rayko
We are updating the data bound to the treeview dynamically which has CheckParents and CheckChildren set to true . Issue is it appears the binding is ignoring these flags. screenshot show it ignoring CheckParents. This REPL shows it ignoring CheckChildren https://blazorrepl.telerik.com/GyuKmVPY13f8gREi18
<TelerikTreeView Data="@PermissionTreeData"
@bind-CheckedItems="@CheckedItems"
CheckBoxMode=@TreeViewCheckBoxMode.Multiple
CheckParents=@true
CheckChildren=@true>
HI:
How Can I change the expanded i/collapsed con from TelerikTreeView?
There is a demo in the documentation but is for the main icon, not for the collapse/expanded icon.
Thanks in advance.
I am using a TelerikTreeView in my component. When I click on a node (an expanded child node), I check whether the form for the currently selected node is dirty. If the form is dirty, I show a prompt asking the user to continue or not. When the user selects no/cancel, the clicked node should not be selected.
I am using the event below.
protected async Task OnItemClickedAsync(TreeViewItemClickEventArgs args)
I can't find a way to cancel this event or to prevent the newly clicked item to be selected. Is there any way to prevent a clicked item to be selected? I have been experimenting with @bind-SelectedItems to no avail. I haven't been able to find a solution for this problem.
Any help is appreciated.