Links
Components libraries
Useful librairies
Description
- Développement frontend avec C#
- Intégration des bibliothèques .NET existantes (nuget)
Permet d'exécuter du bytecode (code intermediaire) dans le navigateur grâce à la javascript runtime sandbox.
WebAssembly est nativement présent dans les navigateurs moderne.
WebAssembly possède un runtime .NET (mono.wasm), ce qui permet d'exécuter des assemblies .NET dans le navigateur.
L'application est téléchargée et exécutée dans le navigateur.
- Excellentes performances
- Pas besoin d'un serveur web ASP.NET Core pour héberger l'application
- Permet une utilisation offline une fois chargée
- Le temps de chargement est long, il faut télécharger l'application, ses dépendances et le .NET runtime
- Les identifiants pour les accès aux bdd et web API sont chargés par chaque client
L'application est exécutée sur le serveur. UI updates, event handling et les appels JavaScript sont pris en charge grâce à une connexion SignalR.
- Pas besoin de WebAssembly
- Chaque interaction utilisateur nécessite un appel au serveur
- Un serveur web ASP.NET Core est nécessaire pour héberger l'application
Pages
| Pages/Items.razor
|
@page "/items" @* url *@
@page "/item/{id:int}" @* url avec un parameter *@
<PageTitle>Items</PageTitle>
@if (Items == null) @* attendre que la valeur soit chargée *@
{
<p><em>Loading...</em></p>
}
else
{ /* ... */ }
|
| Pages/Items.razor.cs
|
public partial class Table : ComponentBase
{
private IReadOnlyCollection<ItemDto> items;
[Parameter]
public int Id { get; set; }
protected override async Task OnInitializedAsync()
{
items = await this.ItemClient.GetAsync();
}
protected override async Task OnAfterRenderAsync(bool firstRender) { }
|
 |
You may need of the ::deep pseudo-element to modify the style of child components. |
| Pages/Items.razor.css
|
/* scoped css only for this page */
/* @import is not allowed in scoped css */
first-level-tag { }
first-level-tag ::deep second-level-tag { }
|
| Pages/MyPage.razor.js
|
export function myFunction() { }
export function myFunctionWithArg(arg) {
return 'ok';
}
|
| Pages/MyPage.razor.cs
|
public partial class MyPage : ComponentBase, IAsyncDisposable
{
[Inject]
private IJSRuntime JS { get; set; } = default!;
private IJSObjectReference? module;
protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
module = await JS.InvokeAsync<IJSObjectReference>("import", "./Pages/MyPage.razor.js");
}
}
private async Task MyJsFunction()
{
if (module is not null)
await module.InvokeVoidAsync("myFunction");
}
private async ValueTask<string?> MyJsFunctionWithArg(string arg)
{
string result = null;
if (module is not null)
await module.InvokeAsync<string>("myFunctionWithArg", arg);
return result;
}
async ValueTask IAsyncDisposable.DisposeAsync()
{
if (module is not null)
await module.DisposeAsync();
}
|
| MyPage.razor
|
<button @onclick=OnButtonClicked>Click me</button>
<button @onclick="() => OnButtonClicked(Item.Name)">Click me</button>
|
| MyPage.razor.cs
|
void OnButtonClicked()
{ }
async Task OnButtonClicked(string name)
{ }
|
preventDefault and stopPropagation
|
<div @onclick="OnDivClicked">
<a href="/page1" @onclick=OnLinkClicked
@onclick:preventDefault @* prevent the navigation to the url but still executes the OnLinkClicked method *@
@onclick:stopPropagation> @* stop the propagation of the event (bubbling), so the OnDivClicked method is never called *@
Page 1
</a>
</div>
|
foreach
|
|
<ul>
@foreach (var item in items)
{
<li>
@item
</li>
}
</ul>
|
| EditItem.razor
|
@page "/edititem/{ItemId:int}"
<EditForm Model="@item"
OnValidSubmit="@HandleValidSubmitAsync"
OnInvalidSubmit="@HandleInvalidSubmitAsync">
<button type="submit">Save</button>
<button @onclick="Cancel">Cancel</button>
</EditForm>
|
| EditItem.razor.cs
|
[Parameter]
public int ItemId { get; set; }
[Inject]
private IItemService ItemService { get; set; }
private Item item = null;
protected override async Task OnInitializedAsync()
{
item = await ItemDataService.GetItemAsync(ItemId);
}
// when the submit button is clicked and the model is valid
private async Task HandleValidSubmitAsync()
{
await ItemService.UpdateItemAsync(item);
}
// when the submit button is clicked and the model is not valid
private async Task HandleInvalidSubmitAsync() { }
|
|
|
<div class="form-group row">
<label for="name"
class="col-sm-3">
Item:
</label>
<InputText id="name"
@bind-Value="Item.Name"
class="form-control col-sm-8"
placeholder="Enter name">
</InputText>
</div>
|
InputTextArea InputNumber InputDate
Input Select
 |
Only support binding of type string. |
|
|
<div class="form-group row">
<label for="country" class="col-sm-3">Color: </label>
<InputSelect id="color"
@bind-Value="CountryId"
class="form-control col-sm-8">
@foreach (var color in Enum.GetValues(typeof(RgbColor)))
{
<option value="@color">@color</option>
}
<option value="@RgbColor.Red">@RgbColor.Red</option>
<option value="@RgbColor.Green">@RgbColor.Green</option>
<option value="@RgbColor.Blue">@RgbColor.Blue</option>
</InputSelect>
</div>
|
| Components/DropDown.cs
|
public sealed class DropDown<T> : InputSelect<T>
{
protected override bool TryParseValueFromString(string value, out T result, out string validationErrorMessage)
{
if (typeof(T) == typeof(string))
{
result = (T)(object)value;
validationErrorMessage = null;
return true;
}
else if (typeof(T) == typeof(int))
{
int.TryParse(value, NumberStyles.Integer, CultureInfo.InvariantCulture, out var parsedValue);
result = (T)(object)parsedValue;
validationErrorMessage = null;
return true;
}
else if (typeof(T).IsEnum)
{
try
{
result = (T)Enum.Parse(typeof(T), value);
validationErrorMessage = null;
return true;
}
catch (ArgumentException)
{
result = default;
validationErrorMessage = $"The {FieldIdentifier.FieldName} field is not valid.";
return false;
}
}
throw new InvalidOperationException($"{GetType()} does not support the type '{typeof(T)}'.");
}
}
|
| _Imports.razor
|
@using MyNamespace.Components
|
Error InputSelect`1[System.Int32] does not support the type 'System.Int32'
To bind to an int, use select instead of InputSelect:
|
|
<div class="form-group row">
<label for="group" class="col-sm-3">Color: </label>
<select id="group"
@bind="@User.Group.Id"
class="form-control col-sm-8">
@foreach (var availableGroup in AvailableGroups)
{
<option value="@availableGroup.Id">@availableGroup.Name</option>
}
</select>
</div>
|
Input CheckBox
|
InputCheckbox requires a cascading parameter of type EditContext.
For example, you can use InputCheckbox inside an EditForm. |
|
|
<div class="form-group row">
<label for="smoker"
class=" offset-sm-3">
<InputCheckbox id="smoker"
@bind-Value="Employee.Smoker">
</InputCheckbox>
Smoker
</label>
</div>
|
|
|
<label>
<input type="checkbox" @onchange="(e) => FilterAsync(e)" />
Only items with ...
</label>
@code {
private async Task FilterAsync(ChangeEventArgs e)
{
if ((bool)e.Value)
{
Items = await this.ItemClient.GetAsync();
}
else
{
Items = await this.ItemClient.GetAsync();
}
}
}
|
|
dotnet add package BlazorInputFile
|
| Pages/_Host.cshtml
|
<script src="_content/BlazorInputFile/inputfile.js"></script>
</body>
|
| _Imports.razor
|
@using BlazorInputFile
|
| Fichier:Blazor.svg
|
<InputFile OnChange="HandleSelectionAsync" />
<p>@OutputMessages</p>
@code {
async Task HandleSelectionAsync(IFileListEntry[] files)
{
var file = files.FirstOrDefault();
if (file != null)
{
OutputMessages += $"Loading {file.Name}";
string jsonContent;
using (var streamReader = new StreamReader(file.Data))
{
jsonContent = await streamReader.ReadToEndAsync();
}
var importedItems = JsonConvert.DeserializeObject<IReadOnlyCollection<ItemDto>>(jsonContent);
OutputMessages += $"<br>{importedItems.Count} items extracted";
}
}
}
|
Align multiple inputs
|
|
<EditForm Model="@myModel">
<table>
<tbody>
<tr>
<td><label for="login">Login: </label></td>
<td>
<InputText id="login"
@bind-Value="myModel.Login"
class="form-control"
placeholder="Lgin">
</InputText>
</td>
</tr>
<tr>
<td><label for="password">Password: </label></td>
<td>
<InputText id="password"
@bind-Value="myModel.Password"
class="form-control"
placeholder="Password">
</InputText>
</td>
</tr>
</tbody>
</table>
<div class="mt-3">
<button class="btn btn-primary btn-sm" @onclick="Save">Save</button>
<button class="btn btn-secondary btn-sm" @onclick="Cancel">Cancel</button>
</div>
</EditForm>
|
One way
Changes made in the UI doesn't change the binded property.
The onchange event can be used to manually update the property.
|
|
<input type="text" value="@Description"
@onchange=@((ChangeEventArgs __e) => Description = __e.Value.ToString())
@onchange=OnInputChanged />
@code {
string Description { get; set; } = "Text";
void OnInputChanged(ChangeEventArgs e) => Description = e.Value.ToString();
}
|
Two way
|
|
<input type="text" @bind="Name" /> @* by default uses the 'on change' event (focus lost) *@
<input type="text" @bind="Name"
@bind:event="oninput" @* use the oninput event instead of the default onchange, the event is triggered on each input key event *@
@bind:after="DoActionAsync" /> @* trigger the DoActionAsync method when the UI text is modified *@
@code {
string Name { get; set; } = "Text";
async Task DoActionAsync() { }
}
|
Form validation
| Item.cs
|
[Required, StringLength(50, MinimumLength = 3, ErrorMessage = "Name must be between 3 and 50 characters")]
public string Name { get; set; }
|
| Pages/ItemEdit.razor
|
<EditForm Model="@item">
<DataAnnotationsValidator />
<ValidationSummary /> @* affiche la liste des messages d'erreur de validation *@
<InputText @bind-value="item.Name"
placeholder="Enter name" />
<ValidationMessage class="offset-sm-3 col-sm-8" For="@(() => Item.Name)" /> @* affiche le message d'erreur de validation *@
|
|
|
dotnet add package Blazored.FluentValidation
|
| _Imports.razor
|
@using Blazored.FluentValidation
|
| Pages/MyForm.razor
|
<EditForm Model="@model" OnValidSubmit="@SubmitValidForm">
<FluentValidationValidator />
|
Manual validation
| Clients/ItemClient.cs
|
public async Task<OperationResult<IReadOnlyCollection<ItemResponse>>> GetItemsAsync(
ItemQuery query,
CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(query);
// client validation
var validator = new ItemQueryValidator();
var validationResult = validator.Validate(query);
if (!validationResult.IsValid)
{
return new OperationResult<IReadOnlyCollection<TransactionResponse>>(validationResult.Errors);
}
|
| Clients/OperationResult.cs
|
public class OperationResult<T>
{
public T? Result { get; set; }
public IDictionary<string, string[]> ValidationErrors { get; } // error messages grouped by property name
public IReadOnlyCollection<string> Errors => ValidationErrors.SelectMany(x => x.Value).ToList();
public bool IsValid => ValidationErrors.Count == 0;
public OperationResult(IDictionary<string, string[]> validationErrors) // for server side validation error
{
ValidationErrors = validationErrors;
}
public OperationResult(IEnumerable<ValidationFailure> validationFailures) // for client side validation errors
{
ValidationErrors = validationFailures
.GroupBy(x => x.PropertyName, x => x.ErrorMessage)
.ToDictionary(x => x.Key, x => x.ToArray());
}
public OperationResult(T result) // for valid result
{
Result = result;
ValidationErrors = new Dictionary<string, string[]>();
}
}
|
Form exemples
Deactivate the form while submitting
| MyPage.razor
|
<EditForm Model="@search"
OnValidSubmit="@HandleValidSubmitAsync">
<DataAnnotationsValidator />
<fieldset disabled="@isSearching">
<div class="row justify-content-center">
<InputText @bind-Value="search.Text"
class="col-sm-6"
placeholder="Nom de table" />
<button type="submit" class="btn btn-primary col-auto">
@if (!isSearching)
{
<span class="oi oi-magnifying-glass" aria-hidden="true"></span>
}
else
{
<span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>
}
</button>
</div>
<div class="row justify-content-center">
<ValidationMessage class="text-danger col-sm-6" For="@(() => search.Text)" />
</div>
</fieldset>
</EditForm>
@if (isSearching)
{
<h5 class="text-center mt-5 mb-2">Loading
<span class="spinner-border spinner-border-sm" role="status"></span>
</h5>
}
else if (tables.Count > 0)
{
<h5 class="text-center mt-5 mb-2">Résultat de la recherche</h5>
}
else if (validSearchHasBeenStarted)
{
<h5 class="text-center mt-5 mb-2">Pas de résultat pour cette recherche</h5>
}
|
| MyPage.razor.cs
|
private bool isSearching { get; set; } = false;
private bool validSearchHasBeenStarted { get; set; } = false;
private async Task HandleValidSubmitAsync()
{
validSearchHasBeenStarted = true;
isSearching = true;
var data = await myClient.FetchDataAsync(search.Text);
isSearching = false;
}
|
| Components/MyComponent.razor
|
|
|
| Components/MyComponent.cs
|
[Parameter]
public EventCallback<bool> MyEventCallback { get; set; }
// invoke asynchronously callback
await MyEventCallback.InvokeAsync(true);
|
| _Imports.razor
|
@* Make components available *@
@using BlazorServerApp.Components
|
| Pages/MyPage.razor
|
<MyComponent @ref="MyComponent"
MyEventCallback="@MyComponent_OnSomethingHappened"></MyComponent>
|
| Pages/MyPageBase.cs
|
protected MyComponentBase MyComponent { get; set; }
public async void MyComponent_OnSomethingHappened()
{
// refresh the DOM if elements have changed
StateHasChanged();
}
|
|
Due to pre-rendering in Blazor Server you can't perform any JS interop until the OnAfterRender lifecycle method. |
| Method
|
Start / End
|
Show
|
| SetParametersAsync |
Start |
false
|
| OnInitializedAsync |
Start |
false
|
| OnAfterRenderAsync |
Start |
false
|
| OnAfterRenderAsync |
End |
false
|
| OnInitializedAsync |
End |
true
|
| OnParametersSetAsync |
Start |
true
|
| OnParametersSetAsync |
End |
true
|
| OnAfterRenderAsync |
Start |
true
|
| OnAfterRenderAsync |
End |
true
|
| SetParametersAsync |
End |
true
|
- OnInitialized OnInitializedAsync
- OnParametersSet OnParametersSetAsync
- OnAfterRender OnAfterRenderAsync
| ChildComponent.razor
|
<button @onclick="OnClickCallback">Click</button>
@code {
[Parameter]
public EventCallback<MouseEventArgs> OnClickCallback { get; set; }
}
|
| Parent.razor
|
@* The ShowMessage is passed to the ChildComponent
When the button will be pressed in the ChildComponent, the ShowMessage will be triggered in the parent *@
<ChildComponent OnClickCallback="@ShowMessage">
Content of the child component is supplied by the parent component.
</ChildComponent>
@code {
private void ShowMessage(MouseEventArgs e)
{ }
}
|
Navigation
|
[Inject]
private NavigationManager NavigationManager { get; set; } = default!;
NavigationManager.NavigateTo("url");
// to implement redirection, use the OnInitializedAsync method otherwise you will get an NavigationException
protected override async Task OnInitializedAsync()
{
NavigationManager.NavigateTo("/item", true, true);
await base.OnInitializedAsync();
}
|
There is no native way in Blazor to go back to the previous page, but there is still the JS way.
|
|
private IJSRuntime JSRuntime { get; set; } = default!;
await JSRuntime.InvokeVoidAsync("history.back")
|
| Program.cs
|
builder.Services.AddTransient<IMyService, MyService>();
|
| Pages/MyPage.razor.cs
|
[Inject]
private IMyService myService { get; set; }
|
| Lifetime
|
Description
|
| Singleton |
creates a single instance of the service.
All components requiring a Singleton service receive the same instance of the service.
|
| Transient |
creates a new instance of the service on each component request.
|
| Scoped |
creates a new instance of the service on each HTTP request but not across SignalR connection/circuit messages.
Which means only when:
- The user closes the browser's window, then opens a new window and navigates back to the app.
- The user closes a tab of the app in a browser window, then opens a new tab and navigates back to the app.
- The user selects the browser's reload/refresh button.
|
| Program.cs
|
builder.Services.AddLocalization();
app.UseRequestLocalization("fr-FR");
|
Static files
| Pages/_Host.cshtml
|
<head>
<link rel="stylesheet" href="css/bootstrap/bootstrap.min.css" />
<link href="css/site.css" rel="stylesheet" />
|
| wwwroot/css/site.css
|
/* custom css */
/* import Iconic font */
@import url('open-iconic/font/css/open-iconic-bootstrap.min.css');
|
- wwwroot/css/font-awesome
- css/all.min.css
- webfonts/*
- LICENSE.txt
| wwwroot/css/site.css
|
@import url('font-awesome/css/all.min.css');
|
| Program.cs
|
//builder.Services.AddServerSideBlazor();
var myWebapiUrl = builder.Configuration["MyWebapiUrl"];
if (string.IsNullOrWhiteSpace(myWebapiUrl))
{
throw new Exception("MyWebapiUrl setting is null");
}
builder.Services.AddHttpClient<IMyClient, MyClient>(
client => client.BaseAddress = new Uri(myWebapiUrl)
);
|
| Program.cs
|
builder.Services.AddScoped(_ => new MyDbContext(builder.Configuration.GetConnectionString("MyDbContext")));
|
| appsettings.json
|
{
"ConnectionStrings": {
"MyDbContext": "Data Source=MyServer; Initial Catalog=MyDb; Integrated Security=True; MultipleActiveResultSets=True;"
},
|
| MyRepository.cs
|
private readonly MyDbContext context;
public MyRepository(MyDbContext context)
{
this.context= context;
}
public Task<Data> FetchDataAsync()
=> context.Data.ToListAsync();
|
DbContext isn't thread safe and isn't designed for concurrent use.
To handle multi-threads scenarios, use a AddDbContextFactory to create a DbContext for each query.
| Program.cs
|
builder.Services.AddDbContextFactory<MyDbContext>();
|
| MyRepository.cs
|
private readonly IDbContextFactory<MyDbContext> contextFactory;
public MyRepository(IDbContextFactory<MyDbContext> contextFactory)
{
this.contextFactory = contextFactory;
}
public async Task<Data> FetchDataAsync()
{
// create a DbContext for this query, then dispose it once the query has been executed
using var context = await contextFactory.CreateDbContextAsync();
}
|
|
|
[Inject]
public ProtectedSessionStorage ProtectedSessionStore { get; set; }
protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
await LoadStateAsync();
StateHasChanged();
}
}
private async Task LoadStateAsync()
{
var fetchValueResult = await ProtectedSessionStore.GetAsync<string>("key");
var value = fetchValueResult.Success ? fetchValueResult.Value : null;
}
await ProtectedSessionStore.SetAsync("key", value);
|
External JS libraries
|
|
# install the LibMan CLI
dotnet tool install -g Microsoft.Web.LibraryManager.Cli
# create the libman.js file
libman init
# available providers: cdnjs (default), jsdelivr (choose this one), unpkg, filesystem
libman install bootswatch@5.0.1 --files dist/darkly/bootstrap.min.css
# uninstall bootstrap
libman uninstall bootstrap@5.0.1
|
Bootstrap
|
|
# jsdelivr provider
# install only bootstrap.min.css and bootstrap.bundle.min.js (with popper)
libman install bootstrap@latest \
--files dist/css/bootstrap.min.css \
--files dist/css/bootstrap.min.css.map \
--files dist/js/bootstrap.bundle.min.js \
--files dist/js/bootstrap.bundle.min.js.map \
--files LICENSE
# default destination path: wwwroot/lib/bootstrap
|
| Pages/_Host.cshtml
|
<head>
<!-- REPLACE <link rel="stylesheet" href="css/bootstrap/bootstrap.min.css" /> BY -->
<link rel="stylesheet" href="lib/bootstrap/css/bootstrap.min.css" />
<link href="css/site.css" rel="stylesheet" />
<script src="lib/bootstrap/js/bootstrap.bundle.min.js"></script>
<script src="_framework/blazor.server.js"></script>
</body>
|
| Pages/Error.cshtml
|
<head>
<!-- REPLACE <link href="~/css/bootstrap/bootstrap.min.css" rel="stylesheet" /> BY -->
<link rel="stylesheet" href="~/lib/bootstrap/css/bootstrap.min.css" />
|
|
Delete the folder wwwroot/css/bootstrap |
|
|
# install the css and fonts only
libman install bootstrap-icons@latest \
--files font/bootstrap-icons.min.css \
--files font/fonts/bootstrap-icons.woff \
--files font/fonts/bootstrap-icons.woff2
# default destination path: wwwroot/lib/bootstrap-icons
|
| Pages/_Host.cshtml
|
<head>
<link rel="stylesheet" href="lib/bootstrap-icons/font/bootstrap-icons.min.css" />
<link href="css/site.css" rel="stylesheet" />
|
| wwroot/css/site.css
|
/* remove this line */
@import url('open-iconic/font/css/open-iconic-bootstrap.min.css');
|
|
Delete the folder wwwroot/css/open-iconic |
| Shared/NavMenu.razor
|
<NavLink class="nav-link" href="" Match="NavLinkMatch.All">
<i class="bi bi-house"></i> Home
</NavLink>
|
| Shared/NavMenu.razor.css
|
/* replace .oi by .bi */
.bi {
width: 2rem;
font-size: 1.1rem;
vertical-align: text-top;
top: -2px;
}
|
| App.razor
|
@* replace RouteView by AuthorizeRouteView *@
<AuthorizeRouteView RouteData="@routeData"
DefaultLayout="@typeof(MainLayout)" />
|
| Shared/LoginDisplay.razor
|
<AuthorizeView>
<Authorized>
<p>@context.User.Identity.Name</p>
</Authorized>
<NotAuthorized>
<a href="login">Log in</a>
</NotAuthorized>
</AuthorizeView>
|
| Startup.cs
|
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints => {});
}
public void ConfigureServices(IServiceCollection services)
{
services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
.AddEntityFrameworkStores<ApplicationDbContext>();
services.AddRazorPages();
services.AddServerSideBlazor();
}
|
|
|
dotnet tool install -g dotnet-aspnet-codegenerator
dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design --version 3.1.3
dotnet add package Microsoft.EntityFrameworkCore.Design --version 3.1.3
dotnet add package Microsoft.AspNetCore.Identity.EntityFrameworkCore --version 3.1.3
dotnet add package Microsoft.AspNetCore.Identity.UI --version 3.1.3
dotnet add package Microsoft.EntityFrameworkCore.SqlServer --version 3.1.3
dotnet add package Microsoft.EntityFrameworkCore.Tools --version 3.1.3
# help
dotnet aspnet-codegenerator identity -h
# list the files that can be scaffolded
dotnet aspnet-codegenerator identity -lf
# scaffold
dotnet aspnet-codegenerator identity -dc MyApplication.Data.ApplicationDbContext --files "Account.Login"
# create the page Area/Identity/Pages/Account/Login.cshtml
|
| Shared/MainLayout.razor
|
<ErrorBoundary @ref="errorBoundary">
<ChildContent>
@Body
</ChildContent>
<ErrorContent Context="e">
@{ OnError(@e); }
<MudAlert Severity="Severity.Error">An exception occured: @e.Message</MudAlert>
</ErrorContent>
</ErrorBoundary>
@code {
[Inject]
private ILogger<MainLayout> Logger { get; set; } = null!;
private ErrorBoundary? errorBoundary;
private void OnError(Exception e)
{
Logger.LogCritical(e, e.Message);
}
// reset the ErrorBoundary to a non-error state on subsequent page navigation events by calling the error boundary's Recover method.
protected override void OnParametersSet()
{
errorBoundary?.Recover();
}
}
|
|
Display detailed error in the client. Never do that in Production, rely better on server log. |
| Program.cs
|
builder.Services.AddServerSideBlazor()
.AddCircuitOptions(o =>
{
o.DetailedErrors = true;
o.DetailedErrors = builder.Environment.IsDevelopment(); // only add details when debugging
});
|
Create a new project
|
|
mkdir MySolution
cd MySolution
dotnet new sln --name MySolution
dotnet new blazorserver -o MyBlazorProject --no-https
dotnet sln add ./MyBlazorProject/MyBlazorProject.csproj
|
Solution Blazor / Webapi
|
|
# create item/item.sln
dotnet new sln -o item
cd item
dotnet new blazorserver --no-https -o item.blazor
dotnet new webapi --no-https -o item.webapi
dotnet sln add item.blazor/item.blazor.csproj
dotnet sln add item.webapi/item.webapi.csproj
|
| item/.vscode/tasks.json
|
{
"version": "2.0.0",
"tasks": [
{
"label": "build blazor",
"command": "dotnet",
"type": "process",
"args": [
"build",
"${workspaceFolder}/item.blazor/item.blazor.csproj",
"/property:GenerateFullPaths=true",
"/consoleloggerparameters:NoSummary"
],
"problemMatcher": "$msCompile"
},
{
"label": "build webapi",
"command": "dotnet",
"type": "process",
"args": [
"build",
"${workspaceFolder}/item.webapi/item.webapi.csproj",
"/property:GenerateFullPaths=true",
"/consoleloggerparameters:NoSummary"
],
"problemMatcher": "$msCompile"
},
{
"label": "build all",
"dependsOn": [
"build blazor",
"build webapi"
],
"group": "build",
"problemMatcher": []
}
]
}
|
| item/.vscode/launch.json
|
{
"version": "0.2.0",
"configurations": [
{
"name": "blazor",
"type": "coreclr",
"request": "launch",
"preLaunchTask": "build blazor",
"program": "${workspaceFolder}/item.blazor/bin/Debug/netcoreapp3.1/item.blazor.dll",
"args": [],
"cwd": "${workspaceFolder}/item.blazor",
"stopAtEntry": false,
"serverReadyAction": {
"action": "openExternally",
"pattern": "\\bNow listening on:\\s+(https?://\\S+)"
},
"env": {
"ASPNETCORE_ENVIRONMENT": "Development"
},
"sourceFileMap": {
"/Views": "${workspaceFolder}/Views"
}
},
{
"name": "webapi",
"type": "coreclr",
"request": "launch",
"preLaunchTask": "build webapi",
"program": "${workspaceFolder}/item.webapi/bin/Debug/netcoreapp3.1/item.webapi.dll",
"args": [],
"cwd": "${workspaceFolder}/item.webapi",
"stopAtEntry": false,
"serverReadyAction": {
"action": "openExternally",
"pattern": "\\bNow listening on:\\s+(https?://\\S+)"
},
"env": {
"ASPNETCORE_ENVIRONMENT": "Development"
},
"sourceFileMap": {
"/Views": "${workspaceFolder}/Views"
}
}
],
"compounds": [
{
"name": "blazor / webapi",
"configurations": [
"blazor",
"webapi"
],
"preLaunchTask": "build all"
}
]
}
|
