ASP.NET Core and Blazor updates in .NET Core 3.0 Preview 9
.NET Core 3.0 Preview 9 is now available and it contains a number of improvements and updates to ASP.NET Core and Blazor.
Here’s the list of what’s new in this preview:
- Blazor event handlers and data binding attributes moved to Microsoft.AspNetCore.Components.Web
- Blazor routing improvements
- Render content using a specific layout
- Routing decoupled from authorization
- Route to components from multiple assemblies
- Render multiple Blazor components from MVC views or pages
- Smarter reconnection for Blazor Server apps
- Utility base component classes for managing a dependency injection scope
- Razor component unit test framework prototype
- Helper methods for returning Problem Details from controllers
- New client API for gRPC
- Support for async streams in streaming gRPC responses
Please see the release notes for additional details and known issues.
Get started
To get started with ASP.NET Core in .NET Core 3.0 Preview 9 install the .NET Core 3.0 Preview 9 SDK.
If you’re on Windows using Visual Studio, install the latest preview of Visual Studio 2019.
.NET Core 3.0 Preview 9 requires Visual Studio 2019 16.3 Preview 3 or later.
To install the latest Blazor WebAssembly template also run the following command:
dotnet new -i Microsoft.AspNetCore.Blazor.Templates::3.0.0-preview9.19424.4
Upgrade an existing project
To upgrade an existing ASP.NET Core app to .NET Core 3.0 Preview 9, follow the migrations steps in the ASP.NET Core docs.
Please also see the full list of breaking changes in ASP.NET Core 3.0.
To upgrade an existing ASP.NET Core 3.0 Preview 8 project to Preview 9:
- Update all Microsoft.AspNetCore.* package references to 3.0.0-preview9.19424.4
- In Blazor apps and libraries:
- Add a using statement for
Microsoft.AspNetCore.Components.Web
in your top level _Imports.razor file (see Blazor event handlers and data binding attributes moved to Microsoft.AspNetCore.Components.Web below for details) - Add a using statement for
Microsoft.AspNetCore.Components.Authorization
in your top level _Imports.razor file. In Blazor WebAssembly apps also add a package reference to Microsoft.AspNetCore.Components.Authorization. - Update all Blazor component parameters to be public.
- Update implementations of
IJSRuntime
to returnValueTask<T>
. - Replace calls to
MapBlazorHub<TComponent>
with a single call toMapBlazorHub
. - Update calls to
RenderComponentAsync
andRenderStaticComponentAsync
to use the new overloads toRenderComponentAsync
that take aRenderMode
parameter (see Render multiple Blazor components from MVC views or pages below for details). - Update App.razor to use the updated
Router
component (see Blazor routing improvements below for details). - (Optional) Remove page specific _Imports.razor file with the
@layout
directive to use the default layout specified through the router instead. - Remove any use of the
PageDisplay
component and replace withLayoutView
,RouteView
, orAuthorizeRouteView
as appropriate (see Blazor routing improvements below for details). - Replace uses of
IUriHelper
withNavigationManager
. - Remove any use of
@ref:suppressField
. - Replace the previous
RevalidatingAuthenticationStateProvider
code with the newRevalidatingIdentityAuthenticationStateProvider
code from the project template. - Replace
Microsoft.AspNetCore.Components.UIEventArgs
withSystem.EventArgs
and remove the “UI” prefix from allEventArgs
derived types (UIChangeEventArgs
->ChangeEventArgs
, etc.). - Replace
DotNetObjectRef
withDotNetObjectReference
. - Replace
OnAfterRender()
andOnAfterRenderAsync()
implementations withOnAfterRender(bool firstRender)
orOnAfterRenderAsync(bool firstRender)
. - Remove any usage of
IComponentContext
and move any logic that should not run during prerendering intoOnAfterRender
orOnAfterRenderAsync
.
- Add a using statement for
- In gRPC projects:
- Update calls to
GrpcClient.Create
with a callGrpcChannel.ForAddress
to create a new gRPC channel and new up your typed gRPC clients using this channel. - Rebuild any project or project dependency that uses gRPC code generation for an ABI change in which all clients inherit from
ClientBase
instead ofLiteClientBase
. There are no code changes required for this change. - Please also see the grpc-dotnet announcement for all changes.
- Update calls to
You should now be all set to use .NET Core 3.0 Preview 9!
Blazor event handlers and data binding attributes moved to Microsoft.AspNetCore.Components.Web
In this release we moved the set of bindings and event handlers available for HTML elements into the Microsoft.AspNetCore.Components.Web.dll assembly and into the Microsoft.AspNetCore.Components.Web
namespace. This change was made to isolate the web specific aspects of the Blazor programming from the core programming model. This section provides additional details on how to upgrade your existing projects to react to this change.
Blazor apps
Open the application’s root _Imports.razor and add @using Microsoft.AspNetCore.Components.Web
. Blazor apps get a reference to the Microsoft.AspNetCore.Components.Web package implicitly without any additional package references, so adding a reference to this package isn’t necessary.
Blazor libraries
Add a package reference to the Microsoft.AspNetCore.Components.Web package package if you don’t already have one. Then open the root _Imports.razor file for the project (create the file if you don’t already have it) and add @using Microsoft.AspNetCore.Components.Web
.
Troubleshooting guidance
With the correct references and using statement for Microsoft.AspNetCore.Components.Web
, event handlers like @onclick
and @bind
should be bold font and colorized as shown below when using Visual Studio.
If @bind
or @onclick
are colorized as a normal HTML attribute, then the @using
statement is missing.
If you’re missing a using statement for the Microsoft.AspNetCore.Components.Web
namespace, you may see build failures. For example, the following build error for the code shown above indicates that the @bind
attribute wasn’t recognized:
CS0169 The field 'Index.text' is never used
CS0428 Cannot convert method group 'Submit' to non-delegate type 'object'. Did you intend to invoke the method?
In other cases you may get a runtime exception and the app fails to render. For example, the following runtime exception seen in the browser console indicates that the @onclick
attribute wasn’t recognized:
Error: There was an error applying batch 2.
DOMException: Failed to execute 'setAttribute' on 'Element': '@onclick' is not a valid attribute name.
Add a using statement for the Microsoft.AspNetCore.Components.Web
namespace to address these issues. If adding the using statement fixed the problem, consider moving to the using statement app’s root _Imports.razor so it will apply to all files.
If you add the Microsoft.AspNetCore.Components.Web
namespace but get the following build error, then you’re missing a package reference to the Microsoft.AspNetCore.Components.Web package:
CS0234 The type or namespace name 'Web' does not exist in the namespace 'Microsoft.AspNetCore.Components' (are you missing an assembly reference?)
Add a package reference to the Microsoft.AspNetCore.Components.Web package to address the issue.
Blazor routing improvements
In this release we’ve revised the Blazor Router
component to make it more flexible and to enable new scenarios. The Router
component in Blazor handles rendering the correct component that matches the current address. Routable components are marked with the @page
directive, which adds the RouteAttribute
to the generated component classes. If the current address matches a route, then the Router
renders the contents of its Found
parameter. If no route matches, then the Router
component renders the contents of its NotFound
parameter.
To render the component with the matched route, use the new RouteView
component passing in the supplied RouteData
from the Router
along with any desired parameters. The RouteView
component will render the matched component with its layout if it has one. You can also optionally specify a default layout to use if the matched component doesn’t have one.
<Router AppAssembly="typeof(Program).Assembly">
<Found Context="routeData">
<RouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" />
</Found>
<NotFound>
<h1>Page not found</h1>
<p>Sorry, but there's nothing here!</p>
</NotFound>
</Router>
Render content using a specific layout
To render a component using a particular layout, use the new LayoutView
component. This is useful when specifying content for not found pages that you still want to use the app’s layout.
<Router AppAssembly="typeof(Program).Assembly">
<Found Context="routeData">
<RouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" />
</Found>
<NotFound>
<LayoutView Layout="typeof(MainLayout)">
<h1>Page not found</h1>
<p>Sorry, but there's nothing here!</p>
</LayoutView>
</NotFound>
</Router>
Routing decoupled from authorization
Authorization is no longer handled directly by the Router
. Instead, you use the AuthorizeRouteView
component. The AuthorizeRouteView
component is a RouteView
that will only render the matched component if the user is authorized. Authorization rules for specific components are specified using the AuthorizeAttribute
. The AuthorizeRouteView
component also sets up the AuthenticationState
as a cascading value if there isn’t one already. Otherwise, you can still manually setup the AuthenticationState
as a cascading value using the CascadingAuthenticationState
component.
<Router AppAssembly="@typeof(Program).Assembly">
<Found Context="routeData">
<AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
</Found>
<NotFound>
<CascadingAuthenticationState>
<LayoutView Layout="@typeof(MainLayout)">
<p>Sorry, there's nothing at this address.</p>
</LayoutView>
</CascadingAuthenticationState>
</NotFound>
</Router>
You can optionally set the NotAuthorized
and Authorizing
parameters of the AuthorizedRouteView
component to specify content to display if the user is not authorized or authorization is still in progress.
<Router AppAssembly="@typeof(Program).Assembly">
<Found Context="routeData">
<AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)">
<NotAuthorized>
<p>Nope, nope!</p>
</NotAuthorized>
</AuthorizeRouteView>
</Found>
</Router>
Route to components from multiple assemblies
You can now specify additional assemblies for the Router
component to consider when searching for routable components. These assemblies will be considered in addition to the specified AppAssembly
. You specify these assemblies using the AdditionalAssemblies
parameter. For example, if Component1
is a routable component defined in a referenced class library, then you can support routing to this component like this:
<Router
AppAssembly="typeof(Program).Assembly"
AdditionalAssemblies="new[] { typeof(Component1).Assembly }>
...
</Router>
Render multiple Blazor components from MVC views or pages
We’ve reenabled support for rendering multiple components from a view or page in a Blazor Server app. To render a component from a .cshtml file, use the Html.RenderComponentAsync<TComponent>(RenderMode renderMode, object parameters)
HTML helper method with the desired RenderMode
.
RenderMode | Description | Supports parameters? |
---|---|---|
Static | Statically render the component with the specified parameters. | Yes |
Server | Render a marker where the component should be rendered interactively by the Blazor Server app. | No |
ServerPrerendered | Statically prerender the component along with a marker to indicate the component should later be rendered interactively by the Blazor Server app. | No |
Support for stateful prerendering has been removed in this release due to security concerns. You can no longer prerender components and then connect back to the same component state when the app loads. We may reenable this feature in a future release post .NET Core 3.0.
Blazor Server apps also no longer require that the entry point components be registered in the app’s Configure
method. Only a single call to MapBlazorHub()
is required.
Smarter reconnection for Blazor Server apps
Blazor Server apps are stateful and require an active connection to the server in order to function. If the network connection is lost, the app will try to reconnect to the server. If the connection can be reestablished but the server state is lost, then reconnection will fail. Blazor Server apps will now detect this condition and recommend the user to refresh the browser instead of retrying to connect.
Utility base component classes for managing a dependency injection scope
In ASP.NET Core apps, scoped services are typically scoped to the current request. After the request completes, any scoped or transient services are disposed by the dependency injection (DI) system. In Blazor Server apps, the request scope lasts for the duration of the client connection, which can result in transient and scoped services living much longer than expected.
To scope services to the lifetime of a component you can use the new OwningComponentBase
and OwningComponentBase<TService>
base classes. These base classes expose a ScopedServices
property of type IServiceProvider
that can be used to resolve services that are scoped to the lifetime of the component. To author a component that inherits from a base class in Razor use the @inherits
directive.
@page "/users"
@attribute [Authorize]
@inherits OwningComponentBase<Data.ApplicationDbContext>
<h1>Users (@Service.Users.Count())</h1>
<ul>
@foreach (var user in Service.Users)
{
<li>@user.UserName</li>
}
</ul>
Note: Services injected into the component using @inject
or the InjectAttribute
are not created in the component’s scope and will still be tied to the request scope.
Razor component unit test framework prototype
We’ve started experimenting with building a unit test framework for Razor components. You can read about the prototype in Steve Sanderson’s Unit testing Blazor components – a prototype blog post. While this work won’t ship with .NET Core 3.0, we’d still love to get your feedback early in the design process. Take a look at the code on GitHub and let us know what you think!
Helper methods for returning Problem Details from controllers
Problem Details is a standardized format for returning error information from an HTTP endpoint. We’ve added new Problem
and ValidationProblem
method overloads to controllers that use optional parameters to simplify returning Problem Detail responses.
[Route("/error")]
public ActionResult<ProblemDetails> HandleError()
{
return Problem(title: "An error occurred while processing your request", statusCode: 500);
}
New client API for gRPC
To improve compatibility with the existing Grpc.Core
implementation, we’ve changed our client API to use gRPC channels. The channel is where gRPC configuration is set and it is used to create strongly typed clients. The new API provides a more consistent client experience with Grpc.Core
, making it easier to switch between using the two libraries.
// Old
using var httpClient = new HttpClient() { BaseAddress = new Uri("https://localhost:5001") };
var client = GrpcClient.Create<GreeterClient>(httpClient);
// New
var channel = GrpcChannel.ForAddress("https://localhost:5001");
var client = new GreeterClient(channel);
var reply = await client.GreetAsync(new HelloRequest { Name = "Santa" });
Support for async streams in streaming gRPC responses
gRPC streaming responses return a custom IAsyncStreamReader
type that can be iterated on to receive all response messages in a streaming response. With the addition of async streams in C# 8, we’ve added a new extension method that makes for a more ergonomic API while consuming streaming responses.
// Old
while (await requestStream.MoveNext(CancellationToken.None))
{
var message = requestStream.Current;
// …
}
// New and improved
await foreach (var message in requestStream.ReadAllAsync())
{
// …
}
Give feedback
We hope you enjoy the new features in this preview release of ASP.NET Core and Blazor! Please let us know what you think by filing issues on GitHub.
Thanks for trying out ASP.NET Core and Blazor!
116 comments
Hello
What about IComponentContext? Now it’s absent in Microsoft.AspNetCore.Components namespace. Thank you.
I have the same issue…
There is an open issue on Github questioning this: https://github.com/aspnet/AspNetCore/issues/13711
It was removed: see https://github.com/aspnet/AspNetCore/commit/1f7d59d8f1e7cd1bc8d816cb1e78f3c40ccc26e7 – also see https://github.com/aspnet/AspNetCore/issues/13703 as you can use
NavigationManager
for prerenderMaybe this comment helps you as well: https://github.com/SamProf/MatBlazor/issues/232#issuecomment-528362115
There seems to be an ommission in the upgrade process you’ve outlined. I tried to upgrade by chat sample https://github.com/conficient/BlazorChatSample from preview 8 to preview 9. The <Router> changes generated lots of errors (despite the app still compiling) – I found that we have two new packages we need to add:
Microsoft.AspNetCore.Blazor.HttpClient
Microsoft.AspNetCore.Blazor.DevServer
You might want to update the post to cover these off?
Yes, painfull process with lots of erros. Got lost now after upgrading the visual preview to 16.3 – would be really helpfull if someone could tell how to avoid Preview9 is used for all existing projects for build and how to force rollback to preview8 to being able to continue working while upgrading the projects later step by step to Preview9.
I don’t think it’s possible to simply downgrade. Install the old version of VS and preview8 and run your project with a previous commit from your git history^^
By default dotnet compiler uses the latest SDK, which is in this case 3.0.100-preview9-014004. You can either uninstall it to return back to preview 8 aand then install it back when it is ready, or you can specify in your project whoch SDK to use in global.json file. See here in details: https://docs.microsoft.com/en-us/dotnet/core/versions/selection
Simply: create global.json file and put into your project root folder. Add the following content:
{ “sdk”: { “version”: “3.0.100-preview8-013656” } }
And rebuild your project. You may need to clean and rebuild in order for it to work. My compiler did not pick it up on incremental build.
Which migration steps were missing for the Router? Most of the changes should already be covered in the Blazor Router improvements section, but let me know if I missed anything and I’m happy to add it.
The Microsoft.AspNetCore.Blazor.HttpClient package was actually introduced in Preview 8, not Preview 9, and is covered in the Preview 8 migration guidance. Microsoft.AspNetCore.Blazor.DevServer package was introduced back in Preview 4.
I have an demo app that’s working on Preview 8 just fine, it only referenced
Microsoft.AspNetCore.Blazor Microsoft.AspNetCore.Blazor.Build
When upgrade to Preview 9 and did the changes to <Router> I got errors – it didn’t like the new syntax.
I found that I need to add
Microsoft.AspNetCore.Blazor.HttpClient Microsoft.AspNetCore.Blazor.DevServer
As well. Not sure when these libs were introduced but don’t remember them from earlier previews
I assume that the router code must have moved to the HttpClient package since I didn’t previously reference it in Preview8, hence the error I got. I expect we can leave the blog post unchanged as people might notice the comments if they too experience errors.
As I understand Core 3 is supposed to be release end of sept. 2019 (this month) I am starting a new project and would like to go with Blazor. Is Preview 9 would be part of the release with Core 3 end of this month. If not is there minor or major changes coming later? more or less I do not burn fingers.
If I were you, I really would wait… There are still a lot of changes going on. At least, it seems like that.
.NET Core 3.0 Preview 9 is the last planned preview release before we ship later this month. We worked pretty hard to get the last batch of Blazor related API changes into Preview 9 and we don’t have plans to make any additional API breaking changes before .NET Core 3.0 ships later this month. It’s a great time to start building with .NET Core 3.0!
How do we replace
EditContext?.FieldClass(FieldIdentifier)
? IsEditContext?.FieldCssClass(FieldIdentifier)
the same? Check https://github.com/aspnet/AspNetCore/issues/13713, please.Yup, FieldCssClass is the new name.
Is there documentation on:
@inherits OwningComponentBase<Data.ApplicationDbContext>
The question is, should be used this when using Entity Framework? If we don’t, what happens?
Thank You
Docs on OwningComponentBase are coming shortly. Because EF Core DbContext are expected to be scoped and generally short lived we recommend using them with OwningComponentBase so that data doesn’t accumulate unnecessarily in the DbContext instance. Using OwningComponentBase will cause the DbContext to have the same lifetime as the component. If you don’t use OwningComponentBase, then the DbContext will live for the life of the connection, which may be problematic if your clients stay connected for a long time.
Could you please inform us next time when the .NET Core 3 version is updated automatically?
Yes, absolutely! I’m sorry if this caught you by surprise. The Visual Studio 16.3 previews all now carry the latest .NET Core 3.0 previews.
Is there any method to avoid prerendering? Simply having <app></app> doesn’t work anymore.
In a Blazor Server app you can use `@(await Html.RenderStaticComponentAsync<App>(RenderMode.Server)) to avoid prerendering. Blazor Server apps no longer use the older CSS selector mechanism.
That’s what I thought, but my experience is that with the mode of ServerPreRendered my application starts and is not functional (The first screen appears but no interaction is possible). When I switch the mode to Server i get as far as seeing the placeholder in the html (using the developer tools in FF) but the application never renders. What I see ‘on screen’ is a blank browser window. What I see in the html is
The same app launched client-side work with no issue.
Any thoughts on what I might be doing wrong in the app?
BTW, this new method removes a use case that I was employing that had html/css in between the <app></app> to show a spinner until the content loaded. That still works with a wasm client but no longer with server side rendering. On the bright side, the startup is so much faster there is little meed for the spinner if server side.
Additional info — Wth ServerPreRendered the html has the placeholders and they are never replaced with active content. When I switch my app to client side wasm execution everything works. The app is embodied in a couple of Razor Class Libraries so my switch is simply changing the DNC startup.cs file (which I do with a configuration switch) to go between CSE/SSE.
Do you see any errors is the browser dev tools console or in the server logs?
If it’s important for your app to still show a spinner while waiting for the component to render, then please open an issue on https://github.com/aspnet/aspnetcore/issues and we’ll discuss possible solutions.
No errors in the dev tools nor the server logs. I have a small repository that demonstrates the problem so I’ll open an issue and reference it there. On the server side I don’t feel the need for the spinner as startup is so fast. On the client I’d like it to be preserved.
I have upgraded a Blazor Web Assembly project from preview 7 to preview 9. Updated VS 2-19, installed new project templates and followed instructions above for Router, etc. After resolving all of the errors, I attempt to build the project from VS and get the following msbuild error:
error MSB3073: The command “dotnet ….<build dependencies, etc> …. exited with code -532462766
Any ideas what is wrong, I have the latest .NET COre 3 preview installed which appears to have been done with the VS update.
Thanks
You can check https://github.com/dodyg/practical-aspnetcore/blob/master/projects/blazor/README.md for Blazor Web Assembly. I’ve upgraded all 17 samples.
Do you see any additional errors in the build output in the output tab in Visual Studio? What about when building the project on the command line using `dotnet build`?
Hi Daniel, yes dotnet build does fail with the same error. Just noticed from VS outout that I also have this:
Unhandled Exception: Mono.Cecil.ResolutionException: Failed to resolve Microsoft.AspNetCore.Components.IComponentContextat Mono.Linker.Steps.MarkStep.HandleUnresolvedType(TypeReference reference)at Mono.Linker.Steps.MarkStep.MarkType(TypeReference reference)at Mono.Linker.Steps.MarkStep.MarkField(FieldReference reference)at Mono.Linker.Steps.MarkStep.InitializeFields(TypeDefinition type)at Mono.Linker.Steps.MarkStep.InitializeType(TypeDefinition type)at Mono.Linker.Steps.MarkStep.InitializeAssembly(AssemblyDefinition assembly)at Mono.Linker.Steps.MarkStep.Initialize()at Mono.Linker.Steps.MarkStep.Process(LinkContext context)at Mono.Linker.Pipeline.ProcessStep(LinkContext context, IStep step)at Mono.Linker.Pipeline.Process(LinkContext context)at Mono.Linker.Driver.Run(ILogger customLogger)at Mono.Linker.Driver.Execute(String[] args, ILogger customLogger)at Mono.Linker.Driver.Main(String[] args)
Looks like you’re still using IComponentContext somewhere in your app. This service was removed in this release. Instead, we now guarantee that OnAfterRender and OnAfterRenderAsync are not called during prerendering.
I’m upgrading to Prev.9 it’s going ok but I can’t seem to find the replacement for keyboard events. Changing UIKeyboardEventArgs to KeyboardEventArgs still gives an error and so does KeyPressEventArgs. What’s the path to take here? Thanks
KeyboardEventArgs is the right type. Are you missing the Microsoft.AspNetCore.Components.Web namespace or package?
I have Microsoft.AspNetCore.Components.Web and Microsoft.AspNetCore installed and still get the error
Error CS0246: The type or namespace name ‘KeyboardEventArgs’ could not be found (are you missing a using directive or an assembly reference?) (CS0246)
dotnet –info
.NET Core SDK (reflecting any global.json):
Version: 3.0.100-preview9-014004
Commit: 8e7ef240a5
Runtime Environment:
OS Name: Mac OS X
OS Version: 10.14
OS Platform: Darwin
RID: osx.10.14-x64
Base Path: /usr/local/share/dotnet/sdk/3.0.100-preview9-014004/
Host (useful for support):
Version: 3.0.0-preview9-19423-09
Commit: 2be172345a
.NET Core SDKs installed:
3.0.100-preview9-014004 [/usr/local/share/dotnet/sdk]
.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.0.0-preview9.19424.4 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.0.0-preview9-19423-09 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]
dotnet –info
.NET Core SDK (reflecting any global.json):
Version: 3.0.100-preview9-014004
Commit: 8e7ef240a5
Runtime Environment:
OS Name: Mac OS X
OS Version: 10.14
OS Platform: Darwin
RID: osx.10.14-x64
Base Path: /usr/local/share/dotnet/sdk/3.0.100-preview9-014004/
Host (useful for support):
Version: 3.0.0-preview9-19423-09
Commit: 2be172345a
.NET Core SDKs installed:
3.0.100-preview9-014004 [/usr/local/share/dotnet/sdk]
.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.0.0-preview9.19424.4 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.0.0-preview9-19423-09 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]
Now that .NET Core 3.0 has shipped I recommend upgrading to the final released version. Also, if you’re using Visual Studio, please upgrade to Visual Studio 2019 16.3. If you’re still having issues after that, please open a GitHub issue on https://github.com/aspnet/aspnetcore/issues with your component code that isn’t compiling and we’ll take a look.
woops, I had a second _Imports.razor that needed
Now I no longer get the error Error CS0246: The type or namespace name ‘KeyboardEventArgs’ could not be found
Excellent! Let us know if you’re still blocked on anything.
Hi Daniel,
I have problems after this update with tablets, both android and iOS. I have made a new project from the template, for this test clientside only. ON my desktop it’s working fine but on tablets it keeps loading…..
You can check it yourself on this url: slimtab.innovixion.nl
I tried accessing the website on my desktop and Android phone (yes, I do sometimes click on random links on the internet :oP) and I get the same experience where the website loads but I get an authorization error. Is it possible you hit some sort of network issue on your tablets? Do you have any firewall/proxy on your network that might be blocking the .dll files from being downloaded? If you think this is a bug in Blazor, please go ahead and file on issue at https://github.com/aspnet/aspnetcore/issues with full details of your setup and we’ll take a look.