daohualiuxiang
/
AspNetCore.Docs
mirror of https://github.com/dotnet/AspNetCore.Docs.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

bad #in-page-anchors (#2518)

pull/2469/merge
Rick Anderson 2017-01-14 11:56:03 -10:00 committed by Tom Dykstra
parent cab82f5867
commit fe9b341361
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
aspnetcore/mvc/controllers/routing.md
View File

@ -197,9 +197,9 @@ public class ProductsController : Controller
This controller defines two actions that would match the URL path `/Products/Edit/17` and route data `{ controller = Products, action = Edit, id = 17 }`. This is a typical pattern for MVC controllers where `Edit(int)` shows a form to edit a product, and `Edit(int, Product)` processes the posted form. To make this possible MVC would need to choose `Edit(int, Product)` when the request is an HTTP `POST` and `Edit(int)` when the HTTP verb is anything else.
The `HttpPostAttribute` ( `[HttpPost]` ) is an implementation of `IActionConstraint` that will only allow the action to be selected when the HTTP verb is `POST`. The presence of an `IActionConstraint` makes the `Edit(int, Product)` a 'better' match than `Edit(int)`, so `Edit(int, Product)` will be tried first. See <!-- Some exception as occured. Possible loss of data --> for details.
The `HttpPostAttribute` ( `[HttpPost]` ) is an implementation of `IActionConstraint` that will only allow the action to be selected when the HTTP verb is `POST`. The presence of an `IActionConstraint` makes the `Edit(int, Product)` a 'better' match than `Edit(int)`, so `Edit(int, Product)` will be tried first.
You will only need to write custom `IActionConstraint` implementations in specialized scenarios, but it's important to understand the role of attributes like `HttpPostAttribute` - similar attributes are defined for other HTTP verbs. In conventional routing it's common for actions to use the same action name when they are part of a `show form -> submit form` workflow. The convenience of this pattern will become more apparent after reviewing the <!-- Some exception as occured. Possible loss of data --> section.
You will only need to write custom `IActionConstraint` implementations in specialized scenarios, but it's important to understand the role of attributes like `HttpPostAttribute` - similar attributes are defined for other HTTP verbs. In conventional routing it's common for actions to use the same action name when they are part of a `show form -> submit form` workflow. The convenience of this pattern will become more apparent after reviewing the [Understanding IActionConstraint](#understanding-iactionconstraint) section.
If multiple routes match, and MVC can't find a 'best' route, it will throw an `AmbiguousActionException`.