Asp.Net Core on Board: Middleware

Foreword

本文介绍Asp.Net Core 中间件。

surroundings

1.Visual Studio 2017
2.Asp.Net Core 2.2

Start

Firsthand: Middleware Overview

1.中间件：添加到应用管道用于处理处理请求和响应的组件。每个组件：
    - 可以选择是否将请求传递到管道中的下一个组件；
    - 可以在调用管道中的下一个组件之前和之后执行工作；

2.管道：如图中黑色箭头，从请求到相应的过程，称之为管道；

3.上图解释：当Request进来时，首先进入Middleware1，然后调用next方法进入Middleware2，
然后调用next方法进入Middleware3，没有next方法所以再依次返回，完成管道处理； 4.三种方法添加中间件： - Use：通常使用Use，Use也可使管道短路，即不调用next方法； - Run：Run一般在管道末端使用Run方法； - Map：Map一般用于处理特定的请求路径。 下面介绍这三种方法的使用。

Second hand: the use of middleware

1.Use of use

1.说一下IApplicationBuilder，Use、Run、和Map添加中间件，其实都是添加到IApplicationBuilder
中的一个组件容器内，在执行时，会遍历这个组件容器，依次执行中间件。

2.Run use

3.Map use

Built-in middleware

Asp.Net Core内置了以下中间件(用法：Use{中间件})：

Middleware	description	order
Authentication	It provides authentication support.	We needed `HttpContext.User`before. OAuth called back to the terminal.
Cookie Policy	Whether tracking user consent to store personal information, and enforce the cookie field (such as `secure`and `SameSite`) minimum standards.	Before issuing the cookie middleware. Example: authentication, session, MVC (TempData).
HEARTS	Configuring cross-domain resource sharing.	Before using components of CORS.
Diagnostics	Configure diagnostic.	Before generating the error components.
Forwarded Headers	The proxy header forwarding to the current request.	Before using updated components field. Example: the program, the host, the IP client, method.
Health Check	Check the application and its dependencies ASP.NET Core operating conditions, such as checking database availability.	If the request matches the endpoint checks operating conditions, for the terminal.
HTTP Method Override	Override allows incoming POST request method.	Before using components have been updated methods.
HTTPS Redirection	Will redirect all HTTP requests to HTTPS (ASP.NET Core 2.1 or later).	Before using components of the URL.
HTTP Strict Transport Security (HSTS)	Add special security header in response to enhanced middleware (ASP.NET Core 2.1 or later).	Before sending the response, after the modification request component. Example: adapter, URL rewriting.
MVC	Processing request (ASP.NET Core Version 2.0 or later) with MVC / Razor Pages.	If the request matches the route, for the terminal.
OWIN	Interoperable OWIN based applications, and middleware servers.	If the request is processed OWIN middleware, for the terminal.
Response Caching	It provides support for caching the response.	Prior to cache components.
Response Compression	Provide support for compressed response.	Before compression required components.
Request Localization	Provide localized support.	Prior to localize sensitive components.
Routing	Request routing definitions and constraints.	Terminal for the matching route.
Session	It provides support for managing user sessions.	Before the components needed sessions.
Static Files	To provide support static files and directories browsing.	If the request matches the file, for the terminal.
URL Rewriting	Support for URL rewriting and redirection requests.	Before using components of the URL.
WebSockets	Enable WebSockets protocol.	Before accepting requests assembly WebSocket required.

Third Hand: Custom Middleware

1. Create a custom middleware class and use it to provide extension methods

2. Configure method call

3. Run

Outcome

本文介绍Asp.Net Core中间件，下局介绍路由，待续...

Author: home dotNET the
link: https: //www.jianshu.com/p/ff1a9bd14eb6
Source: Jane book
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