当ajax调用C#mvc控制器不起作用时,处理会话超时

$.ajax({ 
            type: "POST",url:'/Employee/SaveEmployee',data:
            {
                Location:$("#txtLocation").val(),dateApplied:$("#txtDateApplied").val(),Status:$("#ddStatus").val(),mailCheck:$("#ddMailCheck").val(),...
                ...
                ... 
            },success: function (result) 
            {

            },error: function (msg) 
            {
            }
      });

[Authorize]
public string SaveEmployee(string Location,string dateApplied,string Status,string mailCheck,...)
{
      objEmpMain.FirstName = firstName;
      objEmpMain.LastName = lastName;
      objEmpMain.Initial = Initial;
      objEmpMain.Address1 = Address;
      ...
      ... 
      ...
}

您的AJAX调用的结果仍可能最终显示成功(但不要担心,它实际上不会执行您的操作方法),并调用您的成功处理程序.这是因为您期待HTML,这就是您所接收的内容(尽管如此,生成的HTML可能是您的登录页面,而不是您想要的HTML).顺便说一下,如果你期望JSON(使用dataType：’JSON’),它会触发错误,因为它会将HTML解析为JSON.

您需要做的是阻止FormsAuth重定向AJAX请求的登录页面.现在,AuthorizeAttribute忠实地返回一个NotAuthorizedResult,它向客户端发送HTTP 401 Not Authorized响应,这对您的AJAX客户端来说是理想的.

问题是FormsAuth模块检查StatusCode,如果它是401,它执行重定向.我用这种方式解决了这个问题：

1)创建我自己的衍生类型的AuthorizeAttribute,它在HttpContext.Items中放置一个标志,让我知道授权失败,我应该强制401而不是重定向：

public class AjaxAuthorizeAttribute : AuthorizeAttribute
{
    /// <summary>
    /// Processes HTTP requests that fail authorization.
    /// </summary>
    /// <param name="filterContext">Encapsulates the information for using <see cref="T:System.Web.Mvc.AuthorizeAttribute"/>. The <paramref name="filterContext"/> object contains the controller,HTTP context,request context,action result,and route data.</param>
    protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
    {
        if (filterContext.HttpContext.Request.IsAjaxRequest()) filterContext.HttpContext.Items["AjaxPermissionDenied"] = true;

        base.HandleUnauthorizedRequest(filterContext);
    }
}

2)添加到您的Global.asax.cs：

protected void Application_EndRequest(Object sender,EventArgs e)
    {
        if (Context.Items["AjaxPermissionDenied"] is bool)
        {
            Context.Response.StatusCode = 401;
            Context.Response.End();
        }
     }

3)为jQuery AJAX设置添加一个statusCode处理程序：

$.ajaxSetup({
    statusCode: {
        401: function() {
            window.location.href = "path/to/login";
        }
    }
});

4)将您希望此行为的控制器或操作从使用AuthorizeAttribute更改为AjaxAuthorizeAttribute：

[AjaxAuthorize]
public string SaveEmployee(string Location,...)
{
      objEmpMain.FirstName = firstName;
      objEmpMain.LastName = lastName;
      objEmpMain.Initial = Initial;
      objEmpMain.Address1 = Address;
      ...
      ... 
      ...
}