如何在通过覆盖修改后再次设置 javascript 警报的默认行为

Question

我已经覆盖并修改了警报框的功能，它工作正常，但问题是我已经修改了某些情况下的现有警报（）框，但对于所有情况，我修改后的警报只有在我不加载页面。请找出我在覆盖警报后写的代码。

<logic:notEmpty name="kvbmsg" scope="request">
    <style>


    #alertBox{
    position:absolute;
    top:300px;
    left:500px;
    border:solid 2px black;
    background-color: #cec8c8;
    padding: 50px;
    font-weight:bold;
    visibility: hidden;
}
#alertClose{
    position: absolute;
    right:0;
    top: 0;
    background-color: #cec8c8;
    border: solid 2px #cec8c8;
    color: white;
    width: 1em;
    padding-right: 10px;
    text-align: center; 
    cursor: pointer;
}
    </style>
    <script>

                window.alert = function(msg){
                var id = "alertBox", alertBox, closeId = "alertClose", alertClose;
                alertBox = document.createElement("div");
                document.body.appendChild(alertBox);
                alertBox.id = id;
                alertBox.innerHTML = msg;
                alertClose = document.createElement("div");
                alertClose.id = closeId;
                 alertClose.innerHTML = "<img src=\"/ttk/images/Cancel.png\" width=\"20px\" height=\"20px\">";
                alertBox.appendChild(alertClose);
                alertBox.style.visibility = "visible";
                alertClose.style.visibility = "visible";
                alertClose.onclick = closeAlertBox;
            };

            function closeAlertBox(){

             var alertBox = document.getElementById("alertBox");
             var alertClose = document.getElementById("alertClose");
             alertBox.style.visibility = "hidden";
             alertClose.style.visibility = "hidden";


            }
            alert("<img src=\"/ttk/images/info_icon.png\" width=\"20px\" height=\"20px\">"+" &nbsp;&nbsp;&nbsp;&nbsp;  "+"<%=request.getAttribute("kvbmsg")%>");

            </script>

        </logic:notEmpty>


        <logic:notEmpty name="kvbmsgnull" scope="request">
        <script>
    alert("<%=request.getAttribute("kvbmsgnull")%>");
    </script>
            </logic:notEmpty>

所以请建议我如何在 javascript 中完成任务后再次保留警报的默认行为而无需再次加载页面。

Answer 1

您可以将变量设置为警报函数的引用，然后再将警报设置为该变量。

var tempAlert = window.alert
.
.
.
window.alert = tempAlert

如何在通过覆盖修改后再次设置 javascript 警报的默认行为

how to set default behavior of javascript alert again after modifying by overriding

javascript

alert