使用MVC Action Filter捕获Ajax请求中的重定向并返回JsonResult

Question

在我的ASP.NET MVC 3应用程序中,我有一些可以使用Ajax和非Ajax请求调用的操作方法.操作方法可以返回RedirectResult,我希望在浏览器中加载目标URL - 即使对于Ajax请求也是如此.

我目前的解决方案是使用action方法调用IsAjaxRequest本身.如果为false,则返回RedirectResult.如果为true,则返回包含目标URL的JsonResult,并且我在浏览器中有脚本来读取它并相应地设置window.location.

我希望整理动作方法并在过滤器中处理它.我的问题是目标URL(filterContext.HttpContext.Response.RedirectLocation)在OnResultExecuted以外的过滤器事件处理程序中为空,并且在该处理程序中设置filterContext.Result(并且更改response.StatusCode)不能成功发出JSON响应.

如果我使用其他处理程序之一,例如OnActionExecuted,我可以更改响应以发出JSON,但无法获取目标URL.

两步过程也不起作用 - 如果我在OnActionExecuted中将结果更改为JsonResult,则OnResultExecuted中的RedirectLocation为null.

任何人都可以重新创建此问题或建议更好的解决方案？谢谢.

PS这里是来自OnResultExecuted的代码:

if ((filterContext.Result is RedirectToRouteResult || 
     filterContext.Result is RedirectResult) && 
     filterContext.HttpContext.Request.IsAjaxRequest())
{
    string url = filterContext.HttpContext.Response.RedirectLocation;

    filterContext.HttpContext.Response.StatusCode = (int)HttpStatusCode.OK;

    filterContext.HttpContext.Response.RedirectLocation = "";

    filterContext.Result = new JsonResult
    {
        Data = new { Redirect = url },
        ContentEncoding = System.Text.Encoding.UTF8,
        ContentType = "application/json",
        JsonRequestBehavior = JsonRequestBehavior.AllowGet
    };
}

Answer 1

以下是您可以继续操作的示例:

public override void OnActionExecuted(ActionExecutedContext filterContext)
{
    base.OnActionExecuted(filterContext);

    if (filterContext.HttpContext.Request.IsAjaxRequest())
    {
        string url = "/";
        var redirectResult = filterContext.Result as RedirectResult;
        if (filterContext.Result is RedirectResult)
        {
            // It was a RedirectResult => we need to calculate the url
            var result = filterContext.Result as RedirectResult;
            url = UrlHelper.GenerateContentUrl(result.Url, filterContext.HttpContext);
        }
        else if (filterContext.Result is RedirectToRouteResult)
        {
            // It was a RedirectToRouteResult => we need to calculate
            // the target url
            var result = filterContext.Result as RedirectToRouteResult;
            url = UrlHelper.GenerateUrl(result.RouteName, null, null, result.RouteValues, RouteTable.Routes, filterContext.RequestContext, false);
        }
        filterContext.Result = new JsonResult
        {
            Data = new { Redirect = url },
            JsonRequestBehavior = JsonRequestBehavior.AllowGet
        };
    }
    else
    {
        // TODO: It is not an AJAX request => do whatever you were doing
    }
}