ASP.NET 5 MVC 6：通过“接受”标头路由到操作

Dave New 发表于 Dev

戴夫·纽

假设有两种方法可以通过文件或请求主体将数据发布到同一API端点。

是否可以通过同一资源的Accept标头将其路由到某个动作？

通过请求正文：

// Accept: application/json
[HttpPost]
public IActionResult PostText([FromBody]string text)
{
    ...
    return new HttpOkResult();
}

按文件：

// Accept: application/x-www-form-urlencoded
[HttpPost]
public IActionResult PostFile(IFormFile file)
{
    ...
    return new HttpOkResult();
}

Stas boyarincev

为此使用动作约束。

动作约束

namespace WebApplication
{
    public class PostDataConstraint : ActionMethodSelectorAttribute
    {
        public override bool IsValidForRequest(RouteContext routeContext, ActionDescriptor action)
        {
            var httpContext = routeContext.HttpContext;
            var acceptHeader = //getting accept header from httpContext
            var currentActionName = action.DisplayName;

            if(actionName == "PostFile" and header == "application/x-www-form-urlencoded" ||
               actionName == "PostText" and header == "application/json")
            {
                return true
            }

            return false;
        }
    }
}

动作：

// Accept: application/json
[HttpPost]
[PostData]
public IActionResult PostText([FromBody]string text)
{
    ...
    return new HttpOkResult();
}

// Accept: application/x-www-form-urlencoded
[PostData]
[HttpPost]
public IActionResult PostFile(IFormFile file)
{
    ...
    return new HttpOkResult();
}