126 lines
4.5 KiB
Markdown
126 lines
4.5 KiB
Markdown
|
||
## **0. Middleware and Request Pipeline**
|
||
![[Pasted image 20241105101014.png]]
|
||
![[Pasted image 20241105111037.png]]
|
||
|
||
![[Pasted image 20241105111022.png]]
|
||
|
||
## **1. Routing in ASP.NET Core MVC**
|
||
|
||
Routing is a mechanism to map incoming HTTP requests to specific controller actions. Understanding routing is crucial for managing URL patterns and making your app user-friendly and SEO-optimized.
|
||
|
||
### **Basic Routing Structure**
|
||
|
||
Routes in ASP.NET Core are configured in `Program.cs` (or `Startup.cs` in earlier versions) using the `app.MapControllerRoute` method, which defines how URLs map to controllers and actions.
|
||
|
||
### **Steps and Key Concepts in Routing**
|
||
|
||
1. **Define a Default Route** The default route defines the basic URL pattern that ASP.NET Core will follow.
|
||
|
||
```c#
|
||
app.MapControllerRoute(name: "default", pattern: "{controller=Home}/{action=Index}/{id?}");
|
||
```
|
||
- **Pattern**:
|
||
- `{controller=Home}/{action=Index}/{id?}`:
|
||
- `{controller=Home}`: Specifies the controller, defaulting to `Home`.
|
||
- `{action=Index}`: Specifies the action method, defaulting to `Index`.
|
||
- `{id?}`: Optional parameter for passing an `id`.
|
||
1. **Attribute Routing** Define routes directly within the controller using attributes. This is useful when each action needs a unique route.
|
||
|
||
```c#
|
||
[Route("products")]
|
||
public class ProductsController : Controller
|
||
{
|
||
[HttpGet("all")]
|
||
public IActionResult GetAllProducts() { /*...*/ }
|
||
|
||
[HttpGet("{id}")]
|
||
public IActionResult GetProductById(int id) { /*...*/ }
|
||
}
|
||
```
|
||
1. **Custom Route Parameters and Constraints** You can add custom parameters and enforce constraints directly in the route to manage data types and URL patterns.
|
||
|
||
```c#
|
||
app.MapControllerRoute(name: "custom", pattern: "{controller=Products}/{action=List}/{id:int:min(1)}");
|
||
```
|
||
|
||
- **Constraints**: `{id:int:min(1)}` ensures `id` is an integer greater than or equal to 1.
|
||
- Other constraints include `bool`, `datetime`, `guid`, `minlength(x)`, `maxlength(x)`, and custom regular expressions.
|
||
|
||
1. **Setting Default Actions Based on Controller** To give specific controllers a unique default action, create additional routes before the default route.
|
||
|
||
```c#
|
||
app.MapControllerRoute(name: "gallery", pattern: "Gallery/{action=Main}/{id?}",defaults: new { controller = "Gallery" });
|
||
|
||
app.MapControllerRoute(name: "default", pattern: "{controller=Home}/{action=Index}/{id?}");
|
||
```
|
||
|
||
1. **SEO-Friendly and Readable URLs** For user-friendly URLs, use meaningful route names instead of parameters. This is particularly useful for e-commerce or content-heavy sites.
|
||
```c#
|
||
app.MapControllerRoute(name: "productDetail", pattern: "products/details/{id:int}/{name}");
|
||
```
|
||
|
||
This structure allows URLs like `/products/details/10/laptop`, which is clear and keyword-rich.
|
||
|
||
---
|
||
|
||
## **2. Controllers in ASP.NET Core MVC**
|
||
|
||
Controllers are central in ASP.NET Core MVC and handle requests, retrieve data, and determine how it’s returned to the client.
|
||
|
||
### **Controller Basics**
|
||
|
||
- **Controller Naming**: Controllers usually end with "Controller" (e.g., `HomeController`, `ProductController`).
|
||
- **Actions**: Methods within controllers are called action methods, typically returning a response to the user.
|
||
|
||
### **Steps and Key Concepts in Controllers**
|
||
|
||
1. **Creating a Basic Controller** A controller inherits from the `Controller` base class and contains action methods.
|
||
|
||
```c#
|
||
public class HomeController : Controller
|
||
{
|
||
public IActionResult Index()
|
||
{
|
||
return View();
|
||
}
|
||
}
|
||
```
|
||
|
||
1. **Handling HTTP Methods with Attributes** Controllers use HTTP attributes like `[HttpGet]`, `[HttpPost]`, `[HttpPut]`, and `[HttpDelete]` to specify which HTTP methods they handle.
|
||
|
||
```c#
|
||
[HttpPost]
|
||
public IActionResult CreateProduct(Product product)
|
||
{
|
||
//Handle POST request
|
||
return RedirectToAction("Index");
|
||
}
|
||
```
|
||
|
||
3. **Using Dependency Injection in Controllers** Dependency injection is commonly used in ASP.NET Core to inject services (like a repository) into controllers, supporting clean code and testability.
|
||
|
||
```c#
|
||
public class ProductsController : Controller
|
||
{
|
||
private readonly IProductRepository _repository;
|
||
public ProductsController(IProductRepository repository)
|
||
{
|
||
_repository = repository;
|
||
}
|
||
}
|
||
}
|
||
```
|
||
|
||
1. **Defining Action Parameters** Parameters passed to action methods are automatically bound from the URL or query string. Use model binding to parse complex objects from the request body.
|
||
|
||
|
||
```c#
|
||
public IActionResult EditProduct(int id, string name) {
|
||
// Parameters are bound from the URL }
|
||
```
|
||
|
||
|
||
---
|
||
|