12/29/2019 Admin

Creating A Step-By-Step End-To-End Database Server-Side Blazor Application (updated to .Net Core 3.1)


The primary benefit we have when using server-side Blazor is that we do not have to make web http calls from the client code to the server code. This reduces the code we need to write and eliminates many security concerns.

In this article, we will demonstrate how a list of Weather forecasts can be added to the database by each user. A user will only have the ability to see their own forecasts.


image

You can watch the YouTube video for this tutorial at the following link:

https://www.youtube.com/watch?v=dSW23gkQLP4


Use SQL Server

image

The new project template in Visual Studio will allow you to create a database using SQL Server Express LocalDB. However, it can be problematic to install and configure. Using the free SQL Server 2019 Developer server (or the full SQL Server) is recommended.

Download and install SQL Server 2019 Developer Edition from the following link:

https://www.microsoft.com/en-us/sql-server/sql-server-downloads


Create The Blazor Application

image

Open Visual Studio.


image

Select Create a new Project.


image

Select Blazor App and click Next.


image

Name it EndToEnd and click Create.


image

Select Blazor Server App.


image

Click the Change link under Authentication.


image

Select Individual User Accounts and Store user accounts in-app.


image

Click Create.


image

The project will be created.


Create The Database

image

Open the SQL Server Object Explorer.


image

Add a connection to your local database server if you don’t already have it in the SQL Server list.

For this tutorial, we do not want to use the SQL Express server on (localdb) that you may already see in the list.


image

You will specify just the server and Connect.


image

Expand the tree under the local SQL server, right-click on the Databases folder and select Add New Database.


image

Give the database a name and press Enter.

The database will be created.

image

Right-Click on the Database node and select Properties.


image

Open the Properties window if it is not already opened.

The Properties window for the database will display.

Copy the Connection string for the database.


image

Open the appsettings.json file.


image

Paste in the connection string for the DefaultConnection and save the file.


image

Hit F5 to run the application.


image

The application will open in your web browser.

Click the Register link.


image

Enter the information to create a new account.

Click the Register button.


image

Because this is the first time the database is being used, you will see a message asking you to run the migration scripts that will create the database objects needed to support the user membership code.

Click the Apply Migrations button.


image

After the message changes to Migrations Applied, refresh the page in the web browser.


image

After clicking refresh in your web browser, a popup will require you to click Continue.


image

Click the Click here to confirm your account link.


image

On the Confirm email page, click the name of the application to navigate to the home page.


image

Now you can click the Log in link to log in using the account you just created.


image

You will now be logged into the application.

You can click around the application and see that it works.


image

The Fetch data page currently shows random data. We will alter the application to allow us to add, update, and delete this data in the database.

Close the web browser to stop the application.


Do Not Require Account Confirmation

image

If we do not intend to configure email account verification (using the directions at this link: https://bit.ly/2tf2ym4), we can open the Startup.cs file and change the following line:


								
									services.AddDefaultIdentity<IdentityUser>(
								
									options => options.SignIn.RequireConfirmedAccount =
									true)
								
									.AddEntityFrameworkStores<ApplicationDbContext>();


To:


								
									services.AddDefaultIdentity<IdentityUser>(
								
									options => options.SignIn.RequireConfirmedAccount =
									
										false
									)
								
									.AddEntityFrameworkStores<ApplicationDbContext>();




Create The Database

image

In the SQL Server Object Explorer window, in Visual Studio, we see the tables that the migration scripts added.


image

Right-click on the Tables node and select Add New Table.


image

Paste the following script in the T-SQL window and then click the Update button:


								
									CREATE
									TABLE
									[dbo].[WeatherForecast] (
								
									[Id]
									INT
									IDENTITY
									(1, 1)
									NOT
									NULL,
								
									[Date]
									DATETIME
									NULL,
								
									[TemperatureC]
									INT
									NULL,
								
									[TemperatureF]
									INT
									NULL,
								
									[Summary]
									NVARCHAR
									(50)
									NULL,
								
									[UserName]
									NVARCHAR
									(50)
									NULL,
								
									PRIMARY
									KEY
									CLUSTERED
									([Id]
									ASC)
								
);
								

							


image

The script will prepare.

Click the Update Database button.


image

Back in the Server Explorer window, right-click on Tables and select Refresh.


image

The WeatherForecast table will display.

Right-click on the table and select Show Table Data.


image

We will enter some sample data so that we will be able to test the data connection in the next steps.

Set the UserName field to the username of the user that we registered an account for earlier.


Create The Data Context

image

If you do not already have it installed, install EF Core Power Tools from:

https://marketplace.visualstudio.com/items?itemName=ErikEJ.EFCorePowerTools


image

(Note: Before installing, close Visual Studio)

(Note: Please give this project a 5 star review on marketplace.visualstudio.com!)


image

Right-click on the project node in the Solution Explorer and select EF Core Power Tools then Reverse Engineer.


image

Click the Add button.


image

Connect to the database.



image

Select the database connection in the dropdown and click OK.


image

Select the WeatherForecast table and click OK.


image

Set the values and click OK.


image

In the Solution Explorer, you will see the Data Context has been created.

Click the OK button to close the popup.


image

Open the Startup.cs file.

Add the following code to the ConfigureServices section:


								
									// Read the connection string from the appsettings.json file
								
									// Set the database connection for the EndtoEndContext
								
									services.AddDbContext<EndToEndDB.Data.EndToEnd.EndtoEndContext>(options =>
								
									options.UseSqlServer(
								
									Configuration.GetConnectionString("DefaultConnection")));


Also, change this line:


								
									services.AddSingleton<WeatherForecastService>();


to this:


								
									// Scoped creates an instance for each user
								
									services.AddScoped<WeatherForecastService>();


image

Save the file.

Select Build, then Rebuild Solution.


Read From The Database

image

Delete the Data/WeatherForecast.cs file in the project.

We will use the Data/EndToEnd/WeatherForcast.cs class file created by the EF Core Tools instead.


image

Open the WeatherForecastService.cs file.

Replace all the code with the following code:


								
									using
									EndToEndDB.Data.EndToEnd;
								
									using
									Microsoft.EntityFrameworkCore;
								
									using
									System.Collections.Generic;
								
									using
									System.Linq;
								
									using
									System.Threading.Tasks;
								

								
									namespace
									EndToEnd.Data
								
{
								
									public
									class
									WeatherForecastService
								
									{
								
									private
									readonly
									EndtoEndContext _context;
								

								
									public
									WeatherForecastService(EndtoEndContext context)
								
									{
								
									_context = context;
								
									}
								

								
									public
									async Task<List<WeatherForecast>>
								
									GetForecastAsync(string
									strCurrentUser)
								
									{
								
									// Get Weather Forecasts
									
								
									return
									await _context.WeatherForecast
								
									// Only get entries for the current logged in user
								
									.Where(x => x.UserName == strCurrentUser)
								
									// Use AsNoTracking to disable EF change tracking
								
									// Use ToListAsync to avoid blocking a thread
								
									.AsNoTracking().ToListAsync();
								
									}
								
									}
								
}


This:


								
									private
									readonly
									EndtoEndContext _context;
								
									public
									WeatherForecastService(EndtoEndContext context)
								
									{
								
									_context = context;
								
									}



Connects to the database using the datacontext we created with the EF Core tools.


image

Finally, open the FetchData.razor file.

Replace all the code with the following code:


								
@page "/fetchdata"
								
@using EndToEnd.Data
								
@using EndToEndDB.Data.EndToEnd
								
@inject AuthenticationStateProvider AuthenticationStateProvider
								
@*
								
									Using OwningComponentBase ensures that the service and related services
								
									that share its scope are disposed with the component.
								
									Otherwise DbContext in ForecastService will live for the life of the
								
									connection, which may be problematic if clients stay
								
									connected for a long time.
								

								
									We access WeatherForecastService using @Service
								
*@
								
@inherits OwningComponentBase<
									WeatherForecastService
									>
								

								
									<
									h1
									>Weather forecast</
									h1
									>
								
									<!-- AuthorizeView allows us to only show sections of the page -->
								
									<!-- based on the security on the current user -->
								
									<
									AuthorizeView
									>
								
									<!-- Show this section if the user is logged in -->
								
									<
									Authorized
									>
								
									<
									h4
									>Hello, @context.User.Identity.Name!</
									h4
									>
								
									@if (forecasts == null)
								
									{
								
									<!-- Show this if the current user has no data... yet... -->
								
									<
									p
									>
									<
									em
									>Loading...</
									em
									>
									</
									p
									>
								
									}
								
									else
								
									{
								
									<!-- Show the forecasts for the current user -->
								
									<
									table
									class="table"
									>
								
									<
									thead
									>
								
									<
									tr
									>
								
									<
									th
									>Date</
									th
									>
								
									<
									th
									>Temp. (C)</
									th
									>
								
									<
									th
									>Temp. (F)</
									th
									>
								
									<
									th
									>Summary</
									th
									>
								
									</
									tr
									>
								
									</
									thead
									>
								
									<
									tbody
									>
								
									@foreach (var forecast in forecasts)
								
									{
								
									<
									tr
									>
								
									<
									td
									>@forecast.Date.Value.ToShortDateString()</
									td
									>
								
									<
									td
									>@forecast.TemperatureC</
									td
									>
								
									<
									td
									>@forecast.TemperatureF</
									td
									>
								
									<
									td
									>@forecast.Summary</
									td
									>
								
									</
									tr
									>
								
									}
								
									</
									tbody
									>
								
									</
									table
									>
								
									}
								
									</
									Authorized
									>
								
									<!-- Show this section if the user is not logged in -->
								
									<
									NotAuthorized
									>
								
									<
									p
									>You're not signed in.</
									p
									>
								
									</
									NotAuthorized
									>
								
									</
									AuthorizeView
									>
								
								
@code {
								
									// AuthenticationState is available as a CascadingParameter
								
									[CascadingParameter]
								
									private
									Task<AuthenticationState> authenticationStateTask {
									get;
									set; }
								
									List<WeatherForecast> forecasts;
								

								
									protected
									override
									async Task OnInitializedAsync()
								
									{
								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								

								
									// Get the forecasts for the current user
								
									// We access WeatherForecastService using @Service
								
									forecasts = await @Service.GetForecastAsync(user.Identity.Name);
								
									}
								
}


This code simply calls the GetForecastAsync method we created in the previous step, passing the username of the currently logged in user.

In a normal web application we would have to make a http web call from this client code to the code that connects to the database.

With server-side Blazor we don’t have to do that, yet the call is still secure because the pages are rendered on the server.


image

Build and run the project.

If we are not logged in, and we go to the Fetch data page, we will see a message indicating we are not signed in.


image

Click the Login button.


image

Log in as the user we created data for earlier.


image

After you are logged in, switch to the Fetch data page and you will see the data for the user we entered earlier.


Inserting Data Into The Database

image

Open the WeatherForecastService.cs file and add the following method:


								
									public
									Task<WeatherForecast>
								
									CreateForecastAsync(WeatherForecast objWeatherForecast)
								
									{
								
									_context.WeatherForecast.Add(objWeatherForecast);
								
									_context.SaveChanges();
								

								
									return
									Task.FromResult(objWeatherForecast);
								
									}


image

Open the FetchData.razor file.

Add the following HTML markup directly under the existing table element:


								
									<
									p
									>
								
									<!-- Add a new forecast -->
								
									<
									button
									class="btn btn-primary"
								
									@onclick="AddNewForecast"
									>
								
									Add New Forecast
								
									</
									button
									>
								
									</
									p
									>
								


This adds a button to allow a new forecast to be added.

Add the following code below the previous code:


								
									@if (ShowPopup)
								
									{
								
									<!-- This is the popup to create or edit a forecast -->
								
									<
									div
									class="modal"
									tabindex="-1"
									style="display:block"
									role="dialog"
									>
								
									<
									div
									class="modal-dialog"
									>
								
									<
									div
									class="modal-content"
									>
								
									<
									div
									class="modal-header"
									>
								
									<
									h3
									class="modal-title"
									>Edit Forecast</
									h3
									>
								
									<!-- Button to close the popup -->
								
									<
									button
									type="button"
									class="close"
								
									@onclick="ClosePopup"
									>
								
									<
									span
									aria-hidden="true"
									>X</
									span
									>
								
									</
									button
									>
								
									</
									div
									>
								
									<!-- Edit form for the current forecast -->
								
									<
									div
									class="modal-body"
									>
								
									<
									input
									class="form-control"
									type="text"
								
									placeholder="Celsius forecast"
								
									@bind="objWeatherForecast.TemperatureC"
									/>
								
									<
									input
									class="form-control"
									type="text"
								
									placeholder="Fahrenheit forecast"
								
									@bind="objWeatherForecast.TemperatureF"
									/>
								
									<
									input
									class="form-control"
									type="text"
								
									placeholder="Summary"
								
									@bind="objWeatherForecast.Summary"
									/>
								
									<
									br
									/>
								
									<!-- Button to save the forecast -->
								
									<
									button
									class="btn btn-primary"
								
									@onclick="SaveForecast"
									>
								
									Save
								
									</
									button
									>
								
									</
									div
									>
								
									</
									div
									>
								
									</
									div
									>
								
									</
									div
									>
								
									}


This adds a form (that will be displayed a popup because the class for the DIV is modal), that allows the user to enter (and later edit) data for a forecast.

We do not need JavaScript to make this popup show. We only need to wrap this code with:


								
									
										@if
										(ShowPopup)
									
										{
									
										...
									
										}


When the ShowPopup value is true the popup will show. When the value is false, the popup will disappear.

Add the following code to the @code section:


								
									WeatherForecast objWeatherForecast =
									new
									WeatherForecast();
								

								
									bool
									ShowPopup =
									false;
								
									void
									ClosePopup()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								
									}
								
									void
									AddNewForecast()
								
									{
								
									// Make new forecast
								
									objWeatherForecast =
									new
									WeatherForecast();
								
									// Set Id to 0 so we know it is a new record
								
									objWeatherForecast.Id = 0;
								
									// Open the Popup
								
									ShowPopup =
									true;
								
									}
								
									async Task SaveForecast()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								
									// A new forecast will have the Id set to 0
								
									if
									(objWeatherForecast.Id == 0)
								
									{
								
									// Create new forecast
								
									WeatherForecast objNewWeatherForecast =
									new
									WeatherForecast();
								
									objNewWeatherForecast.Date = System.DateTime.Now;
								
									objNewWeatherForecast.Summary = objWeatherForecast.Summary;
								
									objNewWeatherForecast.TemperatureC =
								
									Convert.ToInt32(objWeatherForecast.TemperatureC);
								
									objNewWeatherForecast.TemperatureF =
								
									Convert.ToInt32(objWeatherForecast.TemperatureF);
								
									objNewWeatherForecast.UserName = user.Identity.Name;
								
									// Save the result
								
									var result =
								
									@Service.CreateForecastAsync(objNewWeatherForecast);
								
									}
								
									else
								
									{
								
									// This is an update
								
									}
								
									// Get the forecasts for the current user
								
									forecasts =
								
									await @Service.GetForecastAsync(user.Identity.Name);
								
									}



image

When you run the project, you can click the Add New Forecast button to add an entry.


image

The form only requires a Fahrenheit, Celsius, and a summary, because the other values (date and username), will be set by the code.


image

After clicking the Save button, the entry is saved to the database and displayed.


Updating The Data

image

Open the WeatherForecastService.cs file and add the following method:


								
									public
									Task<bool>
								
									UpdateForecastAsync(WeatherForecast objWeatherForecast)
								
									{
								
									var ExistingWeatherForecast =
								
									_context.WeatherForecast
								
									.Where(x => x.Id == objWeatherForecast.Id)
								
									.FirstOrDefault();
								

								
									if
									(ExistingWeatherForecast !=
									null)
								
									{
								
									ExistingWeatherForecast.Date =
								
									objWeatherForecast.Date;
								

								
									ExistingWeatherForecast.Summary =
								
									objWeatherForecast.Summary;
								

								
									ExistingWeatherForecast.TemperatureC =
								
									objWeatherForecast.TemperatureC;
								

								
									ExistingWeatherForecast.TemperatureF =
								
									objWeatherForecast.TemperatureF;
								

								
									_context.SaveChanges();
								
									}
								
									else
								
									{
								
									return
									Task.FromResult(false);
								
									}
								

								
									return
									Task.FromResult(true);
								
									}


image

Open the FetchData.razor file.

Replace the existing table element with the following markup that adds an edit button in the last column (that calls the EditForecast method we will add in the next step):


								
									<
									table
									class="table"
									>
								
									<
									thead
									>
								
									<
									tr
									>
								
									<
									th
									>Date</
									th
									>
								
									<
									th
									>Temp. (C)</
									th
									>
								
									<
									th
									>Temp. (F)</
									th
									>
								
									<
									th
									>Summary</
									th
									>
								
									<
									th
									>
									</
									th
									>
								
									</
									tr
									>
								
									</
									thead
									>
								
									<
									tbody
									>
								
									@foreach (var forecast in forecasts)
								
									{
								
									<
									tr
									>
								
									<
									td
									>@forecast.Date.Value.ToShortDateString()</
									td
									>
								
									<
									td
									>@forecast.TemperatureC</
									td
									>
								
									<
									td
									>@forecast.TemperatureF</
									td
									>
								
									<
									td
									>@forecast.Summary</
									td
									>
								
									<
									td
									>
								
									<!-- Edit the current forecast -->
								
									<
									button
									class="btn btn-primary"
								
									@onclick="(() => EditForecast(forecast))"
									>
								
									Edit
								
									</
									button
									>
								
									</
									td
									>
								
									</
									tr
									>
								
									}
								
									</
									tbody
									>
								
									</
									table
									>
								


Add the following code to the @code section:


								
									void
									EditForecast(WeatherForecast weatherForecast)
								
									{
								
									// Set the selected forecast
								
									// as the current forecast
								
									objWeatherForecast = weatherForecast;
								

								
									// Open the Popup
								
									ShowPopup =
									true;
								
									}


This sets the current record to the objWeatherForecast object that the popup is bound to, and opens the popup.

Finally, change the existing SaveForecast method to the following:


								
									async Task SaveForecast()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								
									// A new forecast will have the Id set to 0
								
									if
									(objWeatherForecast.Id == 0)
								
									{
								
									// Create new forecast
								
									WeatherForecast objNewWeatherForecast =
									new
									WeatherForecast();
								
									objNewWeatherForecast.Date = System.DateTime.Now;
								
									objNewWeatherForecast.Summary = objWeatherForecast.Summary;
								
									objNewWeatherForecast.TemperatureC =
								
									Convert.ToInt32(objWeatherForecast.TemperatureC);
								
									objNewWeatherForecast.TemperatureF =
								
									Convert.ToInt32(objWeatherForecast.TemperatureF);
								
									objNewWeatherForecast.UserName = user.Identity.Name;
								
									// Save the result
								
									var result =
								
									@Service.CreateForecastAsync(objNewWeatherForecast);
								
									}
								
									else
								
									{
								
									// This is an update
								
									var result =
								
									@Service.UpdateForecastAsync(objWeatherForecast);
								
									}
								
									// Get the forecasts for the current user
								
									forecasts =
								
									await @Service.GetForecastAsync(user.Identity.Name);
								
									}


This simply adds one line:


								
									// This is an update
								
									var result =
								
									@Service.UpdateForecastAsync(objWeatherForecast);


To the existing method to handle an update rather than an insert.


image

When we run the application, we now have an Edit button to edit the existing record.


image

The existing record will display in the popup, allowing us to edit the data and save it.


image

The updated record is then displayed in the table.


Deleting The Data

image

Open the WeatherForecastService.cs file and add the following method:


								
									public
									Task<bool>
								
									DeleteForecastAsync(WeatherForecast objWeatherForecast)
								
									{
								
									var ExistingWeatherForecast =
								
									_context.WeatherForecast
								
									.Where(x => x.Id == objWeatherForecast.Id)
								
									.FirstOrDefault();
								

								
									if
									(ExistingWeatherForecast !=
									null)
								
									{
								
									_context.WeatherForecast.Remove(ExistingWeatherForecast);
								
									_context.SaveChanges();
								
									}
								
									else
								
									{
								
									return
									Task.FromResult(false);
								
									}
								

								
									return
									Task.FromResult(true);
								
									}


image

Open the FetchData.razor file.

Add code markup for a Delete button under the code markup for the current Save button in the popup:


								
									<!-- Only show delete button if not a new record -->
								
									@if (objWeatherForecast.Id > 0)
								
									{
								
									<!-- Button to delete the forecast -->
								
									<
									button
									class="btn btn-primary"
								
									@onclick="DeleteForecast"
									>
								
									Delete
								
									</
									button
									>
								
									}


Add the following code to the @code section:


								
									async Task DeleteForecast()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								

								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								

								
									// Delete the forecast
								
									var result = @Service.DeleteForecastAsync(objWeatherForecast);
								

								
									// Get the forecasts for the current user
								
									forecasts =
								
									await @Service.GetForecastAsync(user.Identity.Name);
								
									}


image

When we run the code and click the Edit button…


image

… we now see a Delete button that will delete the record.


image

However, when we click the Add New Forecast button that opens the same popup


image

The delete button does not display (because there is no record to delete at this point).


Use Code Behind Method Using Partial Class Support

image

We can code our .razor pages using an @code block with HTML markup in a single file, or with the C# code placed in a code-behind file defined as a partial class.

Create a new class called FetchData.razor.cs using the following code:


								
									using
									EndToEndDB.Data.EndToEnd;
								
									using
									Microsoft.AspNetCore.Components;
								
									using
									Microsoft.AspNetCore.Components.Authorization;
								
									using
									System;
								
									using
									System.Collections.Generic;
								
									using
									System.Threading.Tasks;
								

								
									namespace
									EndToEnd.Pages
								
{
								
									public
									partial
									class
									FetchData
								
									{
								
									// AuthenticationState is available as a CascadingParameter
								
									[CascadingParameter]
								
									private
									Task<AuthenticationState> authenticationStateTask {
									get;
									set; }
								
									List<WeatherForecast> forecasts;
								

								
									protected
									override
									async Task OnInitializedAsync()
								
									{
								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								
									// Get the forecasts for the current user
								
									// We access WeatherForecastService using @Service
								
									forecasts = await @Service.GetForecastAsync(user.Identity.Name);
								
									}
								

								
									WeatherForecast objWeatherForecast =
									new
									WeatherForecast();
								
									bool
									ShowPopup =
									false;
								

								
									void
									ClosePopup()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								
									}
								
									void
									AddNewForecast()
								
									{
								
									// Make new forecast
								
									objWeatherForecast =
									new
									WeatherForecast();
								
									// Set Id to 0 so we know it is a new record
								
									objWeatherForecast.Id = 0;
								
									// Open the Popup
								
									ShowPopup =
									true;
								
									}
								

								
									async Task SaveForecast()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								
									// A new forecast will have the Id set to 0
								
									if
									(objWeatherForecast.Id == 0)
								
									{
								
									// Create new forecast
								
									WeatherForecast objNewWeatherForecast =
									new
									WeatherForecast();
								
									objNewWeatherForecast.Date = System.DateTime.Now;
								
									objNewWeatherForecast.Summary = objWeatherForecast.Summary;
								
									objNewWeatherForecast.TemperatureC =
								
									Convert.ToInt32(objWeatherForecast.TemperatureC);
								
									objNewWeatherForecast.TemperatureF =
								
									Convert.ToInt32(objWeatherForecast.TemperatureF);
								
									objNewWeatherForecast.UserName = user.Identity.Name;
								
									// Save the result
								
									var result =
								
									@Service.CreateForecastAsync(objNewWeatherForecast);
								
									}
								
									else
								
									{
								
									// This is an update
								
									var result =
								
									@Service.UpdateForecastAsync(objWeatherForecast);
								
									}
								
									// Get the forecasts for the current user
								
									forecasts =
								
									await @Service.GetForecastAsync(user.Identity.Name);
								
									}
								

								
									void
									EditForecast(WeatherForecast weatherForecast)
								
									{
								
									// Set the selected forecast
								
									// as the current forecast
								
									objWeatherForecast = weatherForecast;
								
									// Open the Popup
								
									ShowPopup =
									true;
								
									}
								

								
									async Task DeleteForecast()
								
									{
								
									// Close the Popup
								
									ShowPopup =
									false;
								
									// Get the current user
								
									var user = (await authenticationStateTask).User;
								
									// Delete the forecast
								
									var result = @Service.DeleteForecastAsync(objWeatherForecast);
								
									// Get the forecasts for the current user
								
									forecasts =
								
									await @Service.GetForecastAsync(user.Identity.Name);
								
									}
								
									}
								
}
								

							
Remove the entire @code bock from the FetchData.razor page.

The application will still behave the same.


Links

Blazor.net

ASP.NET Core Blazor authentication and authorization

EF Core Power Tools

OwningComponentBase (background)


Download

The project is available on the Downloads page on this site.

You must have Visual Studio 2019 Version 16.3 (or higher) installed to run the code.

An error has occurred. This application may no longer respond until reloaded. Reload 🗙