When you have LazyLoading() enabled on an EF context, the grid throws errors similar to
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NotImplementedException: This is a DynamicProxy2 error: The interceptor attempted to 'Proceed' for method 'Void set_LazyLoader(Microsoft.EntityFrameworkCore.Infrastructure.ILazyLoader)' which has no target.
Here is a sample of the service registration that causes the issue
services.AddDbContext<ApplicationDbContext>(options =>
options
.UseLazyLoadingProxies() // this causes the problem
.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")), ServiceLifetime.Transient);
Here is the full stack trace
Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer: Warning: Unhandled exception rendering component: Object reference not set to an instance of an object.System.NullReferenceException: Object reference not set to an instance of an object.
at Telerik.Blazor.Components.Grid.GridContentCell`1.get_PropInfo()
at Telerik.Blazor.Components.Grid.GridContentCell`1.get_Value()
at Telerik.Blazor.Components.Grid.GridContentCell`1.BuildRenderTree(RenderTreeBuilder __builder)
at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost: Error: Unhandled exception in circuit '-ctJ-ctr0bp4mytl5k9AxUWcoK3LyC8ybsC6BxFhGhA'.
System.NullReferenceException: Object reference not set to an instance of an object.
at Telerik.Blazor.Components.Grid.GridContentCell`1.get_PropInfo()
at Telerik.Blazor.Components.Grid.GridContentCell`1.get_Value()
at Telerik.Blazor.Components.Grid.GridContentCell`1.BuildRenderTree(RenderTreeBuilder __builder)
at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
[2020-01-31T17:09:22.390Z] Error: System.NullReferenceException: Object reference not set to an instance of an object.
at Telerik.Blazor.Components.Grid.GridContentCell`1.get_PropInfo()
at Telerik.Blazor.Components.Grid.GridContentCell`1.get_Value()
at Telerik.Blazor.Components.Grid.GridContentCell`1.BuildRenderTree(RenderTreeBuilder __builder)
at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
[2020-01-31T17:09:22.393Z] Information: Connection disconnected.
Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer: Warning: Unhandled exception rendering component: Exception has been thrown by the target of an invocation.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.NotImplementedException: This is a DynamicProxy2 error: The interceptor attempted to 'Proceed' for method 'Void set_LazyLoader(Microsoft.EntityFrameworkCore.Infrastructure.ILazyLoader)' which has no target. When calling method without target there is no implementation to 'proceed' to and it is the responsibility of the interceptor to mimic the implementation (set return value, out arguments etc)
at Castle.DynamicProxy.AbstractInvocation.ThrowOnNoTarget()
at Castle.DynamicProxy.Internal.CompositionInvocation.EnsureValidTarget()
at Castle.Proxies.Invocations.IProxyLazyLoader_set_LazyLoader.InvokeMethodOnTarget()
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Castle.DynamicProxy.StandardInterceptor.PerformProceed(IInvocation invocation)
at Castle.DynamicProxy.StandardInterceptor.Intercept(IInvocation invocation)
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Castle.Proxies.AttivitaProxy.set_LazyLoader(ILazyLoader value)
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture)
at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, Object[] index)
at Telerik.Blazor.Components.TelerikGridBase`1.Clone(TItem original)
at Telerik.Blazor.Components.TelerikGridBase`1.Edit(GridCommandEventArgs args)
at Telerik.Blazor.Components.TelerikGridBase`1.ExecuteCommand(Object args)
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Telerik.Blazor.Components.Grid.GridRowBase`1.OnExecuteCommand(GridCommandEventArgs commandArgs)
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Telerik.Blazor.Components.Grid.GridContentCell`1.ExecuteCommandAsync(String commandName)
at Telerik.Blazor.Components.Grid.GridContentCell`1.EditAsync()
at Telerik.Blazor.Components.Grid.GridContentCell`1.OnClick()
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)
Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost: Error: Unhandled exception in circuit '-ctJ-ctr0bp4mytl5k9AxUWcoK3LyC8ybsC6BxFhGhA'.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.NotImplementedException: This is a DynamicProxy2 error: The interceptor attempted to 'Proceed' for method 'Void set_LazyLoader(Microsoft.EntityFrameworkCore.Infrastructure.ILazyLoader)' which has no target. When calling method without target there is no implementation to 'proceed' to and it is the responsibility of the interceptor to mimic the implementation (set return value, out arguments etc)
at Castle.DynamicProxy.AbstractInvocation.ThrowOnNoTarget()
at Castle.DynamicProxy.Internal.CompositionInvocation.EnsureValidTarget()
at Castle.Proxies.Invocations.IProxyLazyLoader_set_LazyLoader.InvokeMethodOnTarget()
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Castle.DynamicProxy.StandardInterceptor.PerformProceed(IInvocation invocation)
at Castle.DynamicProxy.StandardInterceptor.Intercept(IInvocation invocation)
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Castle.Proxies.AttivitaProxy.set_LazyLoader(ILazyLoader value)
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture)
at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, Object[] index)
at Telerik.Blazor.Components.TelerikGridBase`1.Clone(TItem original)
at Telerik.Blazor.Components.TelerikGridBase`1.Edit(GridCommandEventArgs args)
at Telerik.Blazor.Components.TelerikGridBase`1.ExecuteCommand(Object args)
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Telerik.Blazor.Components.Grid.GridRowBase`1.OnExecuteCommand(GridCommandEventArgs commandArgs)
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Telerik.Blazor.Components.Grid.GridContentCell`1.ExecuteCommandAsync(String commandName)
at Telerik.Blazor.Components.Grid.GridContentCell`1.EditAsync()
at Telerik.Blazor.Components.Grid.GridContentCell`1.OnClick()
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)
Hi,
Any information on when the Layout Components available in AspNetCore will be available in Blazor?
I am currently putting a proposal together to purchase Telerik for Blazor and could really use some of those components to enhance the application than relying on 3rd-Party integrations.
Hi!
I want to create a grid with multiselect options (controlled by checkboxes in the first column). I have used code from https://demos.telerik.com/blazor-ui/grid/selection but when i try this code in my project there are no checkboxes in the first column, just empty cells. Am i the only one with this problem?
I'd like to make a suggestion.
When one of the third party vendors became involved in producing Blazor components, they opted to wrap their existing 65+ JS components as "Blazor" components. At first, I though that's not as good as Native components that Telerik is doing.
But, as I then read more about their plan, they basically offered a full solutions from their JS library to developers, so we, the developers can start building a complete business application and as long as the vendor doesn't change the Wrapper API and only change the back end, their changes should work on the developer side.
Their idea was, to give us a jump start with JS and we start using counterpart Native Blazor components, and as as they become available, the components get changed to Native Blazor, and the apps written by us continue working.
I think this is a great strategy to have the full suite available to us from start to build apps than waiting for each Native component to be build.
My suggestion is to do the same, i.e. the word processing component where it is needed and we can build our app using the JS Word processor and by the time we are ready, Telerik might have the Word processor replaced by Native Blazor. This way we can build our apps with a full suite from the start than waiting for essential components to be built.
I hope the team would consider such strategy if possible.
Thanks!
..Ben
Hi!
I'm trying out Marin Bratnov's code (from a Link - demonstration code). When i try to write a letter in a TelerikComboBox control it is automatically cleared out. I get the same behavior in my own project too. Filtering TelerikComboBox outside the grid works perfecly. Please check te video.
It seems like Blazor on the server-side will be re-branded as Razor Components. Will Telerik support it?
I have a TelerikComboBox in an EditorTemplate within a Grid. Code looks like this:
<TelerikComboBox Data="@CustomerPayCodes"
@bind-Value="@PayItemMapInEdit.ClientPayCode.UniqueId"
Placeholder="Select..."
Filterable="true"
TextField="PayCodeDisplayName"
ValueField="UniqueId"
@ref="_clientPayCodeComboBox"
Width="auto"
Enabled="@(string.IsNullOrEmpty(_payItemTextBoxRef?.Value))">
</TelerikComboBox>
Where reference prop looks like this:
private TelerikComboBox<PayCode, Guid> _clientPayCodeComboBox;
When adding a new row, the Placeholder text becomes the empty GUID, until I click in the box and then outside, upon it changes to correct "Select...". The GUID is never supposed to be showed at all in the box, that is only the binded value.
See attached pictures.
Please advice.
Br,
Sten
I have an animationcontainer which I in overridden OnAfterRenderAsync(bool firstRender) call:
await AnimationContainerSettings.ShowAsync();...since it is the only way to show the AnimationContainer from start. However, when I in some cases return to the page, the animationcontainer will only show itself if I delay the call with e.g. 1000 ms:
await Task.Delay(1000);
await AnimationContainerSettings.ShowAsync();What could be possible reasons for this be? If I want my AnimationContainer to be visible as default when page is either Initialized or after rendering has occured, where and how should I call ShowAsync()?
Br,
Sten
When I create multiple tabs and each tab has the same type of component, the OnInitialized is only running for the first one I click on.
Here is a simplified example to demonstrate:
MAIN PAGE:
@page "/tabtest"
@using Telerik.Blazor.Components
<div>Product XYZ</div>
<TelerikTabStrip TabPosition="Telerik.Blazor.TabPosition.Top" @ref="productTabStrip" @bind-ActiveTabIndex="@ActiveTabIndex">
<TabStripTab Title="Details">
<div class="container sms-tab-content">
GENERAL PRODUCT INTRO STUFF HERE
</div>
</TabStripTab>
@foreach (var item in listOfWidgets)
{
<TabStripTab Title="@item.WidgetName" Disabled="false">
<Widget WidgetID="@item.WidgetID" WidgetName="@item.WidgetName" />
</TabStripTab>
}
</TelerikTabStrip>
<div style="margin-top: 15px;">
<div><b>Below is a flat non-tab example of repeating widgets:</b></div>
@foreach (var item in listOfWidgets)
{
<Widget WidgetID="@item.WidgetID" WidgetName="@item.WidgetName" />
}
</div>
@code {
Telerik.Blazor.Components.TelerikTabStrip productTabStrip;
public int ActiveTabIndex { get; set; } = 0;
protected class Widget
{
public int WidgetID { get; set; }
public string WidgetName { get; set; }
}
private List<Widget> listOfWidgets = new List<Widget>();
protected void GetData()
{
listOfWidgets.Add(new Widget { WidgetID = 1, WidgetName = "Cog" });
listOfWidgets.Add(new Widget { WidgetID = 2, WidgetName = "Wheel" });
listOfWidgets.Add(new Widget { WidgetID = 3, WidgetName = "Bloof" });
}
protected override void OnInitialized()
{
GetData();
}
}
WIDGET COMPONENT:
@page "/widget/{WidgetID:int}/{WidgetName}"<div>
<div>@WidgetID</div>
<div>@WidgetName</div>
<div>@ExtraWidgetInfo</div>
</div>
@code {
[Parameter] public int WidgetID { get; set; } = 0;
[Parameter] public string WidgetName { get; set; } = "Nothing";
private string ExtraWidgetInfo { get; set; } = "Stuff";
protected override void OnInitialized()
{
if (WidgetName == "Cog")
ExtraWidgetInfo = "This is good info about cogs.";
if (WidgetName == "Wheel")
ExtraWidgetInfo = "This is good info about wheels.";
if (WidgetName == "Bloof")
ExtraWidgetInfo = "This is good info about bloofs.";
}
}
Looking for feature parity with - https://www.telerik.com/kendo-react-ui/components/grid/data-operations/odata-server-operations/
ADMIN NOTE: The goal is to expose a method like args.Request.ToODataString() for the grid OnRead event, so you can pass this on to a service so it knows the grid state (page size, current page, filtering,..). The grid will still expect the total of items and the current page of data to be set in the local fields.
Our grids / drop downs / comboboxes pull 1000s of items, resulting in JSON of 20mb+ if we pull all of the elements to the client. The OData server operations have greatly reduced what we send over the wire, and have worked amazing well in our current React application. Would love to have the same capability for Blazor client side. We are treating Blazor as a client side replacement for React/Redux, we do not want to run Server Side Blazor.
We’ve the use case of an editable combo-box and until now, we used to it with a textbox and a gridview to achieve this with your components.
On the demo page, when I hover over menu items "Overview" and "Demos" and "Roadmap" it changes background color to gray. When I load it into a project with the verbatim demo code no background color change occurs except on "Roadmap".
<TelerikMenu Data="@MenuItems"
ParentIdField="@nameof(MenuItem.SectionId)"
IdField="@nameof(MenuItem.Id)"
TextField="@nameof(MenuItem.Section)">
</TelerikMenu>
@code {
public List<MenuItem> MenuItems { get; set; }
public class MenuItem
{
public int Id { get; set; }
public int? SectionId { get; set; }
public string Section { get; set; }
}
protected override void OnInitialized()
{
MenuItems = new List<MenuItem>()
{
new MenuItem()
{
Id = 1,
Section = "Overview"
},
new MenuItem()
{
Id = 2,
Section = "Demos"
},
new MenuItem()
{
Id = 3,
Section = "Roadmap"
},
new MenuItem()
{
Id = 4,
SectionId = 3,
Section = "What's new"
},
new MenuItem()
{
Id = 5,
SectionId = 3,
Section = "Roadmap"
},
new MenuItem()
{
Id = 6,
SectionId = 3,
Section = "Release History"
}
};
base.OnInitialized();
}
}