使用Ajax轮询检测当前会话状态

以下是代码示例：

首先，您需要添加一个名为"CheckSessionState"的Web服务，用于检测会话状态。示例代码如下：

[WebMethod(EnableSession = true)] public static bool CheckSessionState() { return HttpContext.Current.Session != null && HttpContext.Current.Session["UserId"] != null; }

接下来，您可以使用Ajax轮询调用此Web服务检查会话状态。示例代码如下：

function CheckSessionState() { var isSessionExpired = true; // Assume session is expired by default

$.ajax({
    type: "POST",
    url: "/your-app-path/CheckSessionState.asmx/CheckSessionState",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (data) {
        if (data.d) {
            isSessionExpired = false; // Session is active
        }
    },
    async: false // Make sure the function waits for the response before returning
});

return isSessionExpired;

}

最后，您可以在页面中定期调用此函数来检查会话状态。示例代码如下：

window.setInterval(function () { if (CheckSessionState()) { // Redirect to login page or show a message alert("Your session has expired. Please log in again."); window.location.href = "/your-app-path/login.aspx"; // Redirect to login page } }, 5000); // Check the session state every 5 seconds (adjust as needed)