What is JS interop in Blazor?
In a Blazor application, you can call JavaScript functions from C# (.NET) methods and vice versa. This is referred to as “JavaScript interoperability” or “JS interop.” The JS interop allows you to integrate JavaScript libraries into your Blazor application, and its primary function is to handle DOM manipulation and browser API calls. Please refer to this link to learn more about JS interop in Blazor. Please refer to this link for calling and implementing JS interop in Blazor.
How do you fix “The CORS protocol does not allow specifying a wildcard (any) origin and credentials at the same time” error in Blazor Server application?
In a Blazor Server application, if you want to use both AllowCredentials() and AllowAnyOrigin() with respect to CORS settings, then add SetIsOriginAllowed(Func<string,bool> predicate) under ConfigureServices in the Startup.cs file instead of using AllowAnyOrigin(). See the following code snippet. [Startup.cs] Refer to this link for more information.
How do I change the CSS value directly in Blazor?
You can change the CSS value in the Blazor application by using the following options. NOTE: In CSS, the “!important” rule is used to give a property more weightage, that is, it will override all the previous styling rules applied to that element for that specific property. [Index.razor] View Sample in GitHub
How do I enable or disable the submit button based on the form validation state?
Use the disabled=”@(!context.Validate()) attribute for the submit button component to validate the form to display and enable or disable the button. If an Error message occurs in form validation, the button is disabled.Follow the code below to enable or disable the submit button based on the form validation state.[Index.razor] Refer to this link for more details.
How do I use stored procedures in Blazor application?
Stored procedures are pieces of reusable code that you can save in a database data dictionary. They help you extract, edit, and remove data from a database without writing the code to do so again and again. It also saves your time, lessens your workload, and increases your productivity.Follow these steps to use stored procedures in a Blazor application: Create a new Blazor application and add the Microsoft.EntityFrameworkCore, Microsoft.EntityFrameworkCore.SqlServer, Microsoft.EntityFrameworkCore.Design, Microsoft.EntityFrameworkCore.Tools NuGet packages using the NuGet package manager. Create a class named EmpClass.cs in the Data folder and define the properties that are already in the database table.[Empclass.cs] public class EmpClass{ [Key] public int Empid { get; set; } public string? Empname { get; set; } public string? Department { get; set; } public DateTime joinDate { get; set;}} [EmpClass table]Also Define inserted Employee Details in stored procedure. CREATE PROCEDURE [dbo].[InsertEmpdetails]@Empname nvarchar(150),@Department nvarchar(150), @joinDate datetime ASInsert into EmpClass(Empname,Department,joinDate) values (@Empname,@Department,@Joindate)RETURN 0 Add the virtual property for the DbSet from EmpClass to insert records in the database under the Data folder.[ApplicationDbContext.cs] public class ApplicationDbContext:DbContext { public ApplicationDbContext(DbContextOptions options ) : base(options) { } public virtual DbSet InsertRecord { get; set; }} Connect the SQL Server database to the Blazor application by choosing (View –> Server Explorer). Right-click the Data Connections and choose Add connection in Visual Studio. Add your server name and DB name to connect the database to the Blazor application.The database is now connected to the Blazor application. Add the connection string configurations to the appsetting.json file.[appsetting.json] { “ConnectionStrings”: { “Myconnection”: ” “Data Source={{Server_Name}};Initial Catalog={{DataBase_Name}};Integrated Security=True”” }, “Logging”: { …… }, “AllowedHosts”: “*”} Create an EmpServices class in the Services folder and define the ExecuteSqlRaw extension method to execute a stored procedure.[EmpServices.cs] using {Your App Name}.Data;using Microsoft.EntityFrameworkCore;namespace {Your App Name}.Services{ public class EmpService { protected readonly ApplicationDbContext? _dbcontext; public EmpService ( ApplicationDbContext? _db ) { _dbcontext = _db; } public EmpClass AddNewRecord ( EmpClass? ec) { //Here define the ExecuteSqlRaw extension method to execute a stored procedure with InsertEmpdetails _dbcontext!.Database.ExecuteSqlRaw(“InsertEmpdetails {0},{1},{2}”, ec?.Empname!, ec?.Department!, ec!.Joindate); _dbcontext.SaveChanges(); return ec; } }} Add the DbContext configuration to the Program.cs file. builder.Services.AddDbContext(options => options.UseSqlServer(“name=ConnectionStrings:Myconnection”));builder.Services.AddScoped(); Insert Record Into Database Using Stored Procedure implement in index.razor page @page “/”@using {Your App Name}.Data@using {Your App Name}.Services@inherits OwningComponentBase<EmpService><h1>Insert Record Into Database Using Stored Procedure</h1><hr/><EditForm Model=”@ec” OnValidSubmit=”@Insertdata”> <table border=”1″> <tr> <td>Employee Name</td> <td><input type=”text” placeholder=”Enter Employee Name” @bind=”ec.Empname”/></td> </tr> <tr> <td>Department</td> <td><input type=”text” placeholder=”Enter Department” @bind=”ec.Department” /></td> </tr> <tr> <td>Joindate</td> <td><InputDate @bind-Value=”ec.Joindate”></InputDate></td> </tr> <tr> <td>Joindate</td> <td><input type=”submit” value=”Insert”/></td> </tr> </table></EditForm>@code{ EmpClass ec = new EmpClass(); void Insertdata () { ec.Empid = 0; Service.AddNewRecord(ec); }} Press Ctrl + F5 to run the application and see the output in the following image. View Sample in GitHub
