如何在asp.net中调用WebMethod并显示报警消息

function displayAlertMessage(message) {
    alert(message);
}

using System.Web.Services;

public class MyWebService : WebService
{
    [WebMethod]
    public static string GetAlertMessage()
    {
        // 执行一些逻辑，获取报警消息
        string alertMessage = "这是一个报警消息！";

        return alertMessage;
    }
}

function callWebMethod() {
    PageMethods.GetAlertMessage(onSuccess, onFailure);
}

function onSuccess(result) {
    displayAlertMessage(result);
}

function onFailure(error) {
    console.log(error.get_message());
}

<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true"></asp:ScriptManager>

<script type="text/javascript">
    function displayAlertMessage(message) {
        alert(message);
    }

    function callWebMethod() {
        PageMethods.GetAlertMessage(onSuccess, onFailure);
    }

    function onSuccess(result) {
        displayAlertMessage(result);
    }

    function onFailure(error) {
        console.log(error.get_message());
    }
</script>

<button type="button" onclick="callWebMethod()">调用WebMethod并显示报警消息</button>