Project
- Open the Visual Studio.
- Create web project using ASP.NET Core Empty template.
- Project name: RPExercises
- Solution name: RPExercises
- .NET Core version: 5.0
- Add the AddRazorPages() into the IServiceCollection in Startup class.
- Use MapRazorPages() as terminal middleware in Startup class.
Look at the below updated code in Startup class.
Startup.cs
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
namespace CascadingDropdownsRP
{
public class Startup
{
// This method gets called by the runtime. Use this method to add services to the container.
// For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
public void ConfigureServices(IServiceCollection services)
{
services.AddRazorPages();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
});
}
}
}- Add a new folder and rename it Pages.
- Add a Razor Page in Pages folder and name it Index. Two files are generated which are Index.cshtml and Index.cshtml.cs
- Add a folder and rename it Models.
- In Models folder, create a model class called Student.
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
namespace RPExercises.Models
{
public class Student
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Required]
[MinLength(1)]
[MaxLength(20)]
public string Name { get; set; }
public bool IsPassed { get; set; }
[Required]
public Qualification Degree { get; set; }
}
public enum Qualification
{
BA, MA, BCA, MCA
}
} Install the EF Core packages by running the following commands.
- Install-Package Microsoft.EntityFrameworkCore -version 5.0
- Install-Package Microsoft.EntityFrameworkCore.Design -version 5.0
- Install-Package Microsoft.EntityFrameworkCore.Tools -version 5.0
- Install-Package Microsoft.EntityFrameworkCore.SqlServer -version 5.0
Add a folder and rename it Data. In this folder, add AppDbContext class as given below.
using Microsoft.EntityFrameworkCore;
using RPExercises.Models;
namespace RPExercises.Data
{
public class AppDbContext: DbContext
{
public AppDbContext(DbContextOptions<AppDbContext> options)
: base(options)
{
}
public DbSet<Student> tblStudents { get; set; }
}
}
Add Connection String in appsettings.json file.
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft": "Warning",
"Microsoft.Hosting.Lifetime": "Information"
}
},
"ConnectionStrings": {
"DBCS": "Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=Appliedk11;Integrated Security=True;Connect Timeout=30;Encrypt=False;Trust Server Certificate=False;Application Intent=ReadWrite;Multi Subnet Failover=False"
},
"AllowedHosts": "*"
}
Next step. Update the Startup class to add DbContext service with SQLServer database. .
public void ConfigureServices(IServiceCollection services)
{
services.AddRazorPages();
services.AddDbContext<AppDbContext>(options =>
{
options.UseSqlServer(_cfg.GetConnectionString("DBCS"));
});
}
Perform Add-Migration and Update-Database commands in Package Manager Console.
Now update the Index.cshtml file.
@page "{handler?}"
@using RPExercises.Models;
@model RPExercises.Pages.IndexModel
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
<h2>Create students</h2>
<style type="text/css">
body {
margin-left: 8%;
}
.myclass {
padding: 5px;
border: 2px solid blue;
background-color: beige;
width: 30%;
text-align: left;
}
</style>
<form method="post" class="myclass">
<h3> Input student details</h3>
<label hidden asp-for="student.Id">Id</label>
<input hidden asp-for="student.Id" />
<label asp-for="student.Name" >Name</label>
<input asp-for="student.Name" />
<br />
<label asp-for="student.IsPassed">IsPassed</label>
<input asp-for="student.IsPassed" />
<br />
<label asp-for="student.Degree">Highest Degree</label>
BA<input type="radio" asp-for="student.Degree" value="@Qualification.BA" />
MA<input type="radio" asp-for="student.Degree" value="@Qualification.MA" />
BCA<input type="radio" asp-for="student.Degree" value="@Qualification.BCA" />
MCA<input type="radio" asp-for="student.Degree" value="@Qualification.MCA" />
<br />
<br />
<input type="submit" value="@ViewData["btnLabel"]" style="background-color:green;color:wheat;margin-left:80%" />
</form>
<br />
<hr />
<h2>List students</h2>
Students Count: @Model.students.Count
<br/>
<table border="1" class="myclass">
<tr>
<th>Id</th>
<th>Name</th>
<th>Is Passed</th>
<th>Degree</th>
<th>Action</th>
</tr>
@foreach (Student s in Model.students)
{
<tr>
<td>@s.Id</td>
<td>@s.Name</td>
<td>@s.IsPassed</td>
<td>@s.Degree</td>
<td>
<a asp-page-handler="Edit" asp-route-id="@s.Id">Edit</a>|
<a asp-page-handler="Delete" asp-route-id="@s.Id">Delete</a>
</td>
</tr>
}
</table>Update the Index.cshtml.cs file.
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.EntityFrameworkCore;
using RPExercises.Data;
using RPExercises.Models;
using System.Collections.Generic;
using System.Threading.Tasks;
namespace RPExercises.Pages
{
public class IndexModel : PageModel
{
[BindProperty]
public Student student { get; set; }
public List<Student> students { get; set; } = new List<Student>();
private readonly AppDbContext ctx;
public IndexModel(AppDbContext ctx)
{
this.ctx = ctx;
}
public async Task<IActionResult> OnGet()
{
students = await ctx.tblStudents.ToListAsync();
ViewData["btnLabel"] = "Create";
return Page();
}
public async Task<IActionResult> OnPost()
{
if (student.Id==0)
{
await ctx.tblStudents.AddAsync(student);
await ctx.SaveChangesAsync();
}
else
{
Student studentEdit = await ctx.tblStudents.FindAsync(student.Id);
if (HttpContext.Request.Path.Value.ToLower().Contains("edit"))
{
studentEdit.Id = student.Id;
studentEdit.Name = student.Name;
studentEdit.IsPassed = student.IsPassed;
studentEdit.Degree = student.Degree;
ctx.Entry(studentEdit).State = EntityState.Modified;
}
if (HttpContext.Request.Path.Value.ToLower().Contains("delete"))
{
ctx.Entry(studentEdit).State = EntityState.Deleted;
}
ctx.SaveChanges();
}
return RedirectToPage();
}
public async Task<IActionResult> OnGetEdit(int id)
{
// get data from table
Student studentEdit = await ctx.tblStudents.FindAsync(id);
// update form by updating BindProperty
student = studentEdit;
students = await ctx.tblStudents.ToListAsync();
ViewData["btnLabel"] = "Edit";
return Page();
}
public async Task<IActionResult> OnGetDelete(int id)
{
// get data from table
Student studentDelete = await ctx.tblStudents.FindAsync(id);
// update form by updating BindProperty
student = studentDelete;
students = await ctx.tblStudents.ToListAsync();
ViewData["btnLabel"] = "Delete";
return Page();
}
}
}
Run the application and do CRUD operations. We get the following output.
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