在更新面板中异步回发后如何在客户端推迟更新

Question

我有一个使用 UpdatePanels 的 asp.net 的旧系统

postback完成后，我们知道UpdatePanel的内部更新了

我可以在客户端以某种方式延迟此更新吗？这可能吗？

所以就像，当postback 启动时，我在客户端设置了一个javascript datetime object

一旦postback 完成，并从服务器返回data，在更新client side interface 之前，我检查已经过了多少毫秒，我延迟更新客户端直到某些毫秒过去

这可能吗？

asp.net 4.5 c#

让我澄清一下

我希望页面的每次更新恰好在 ajax 回发请求开始后 500 毫秒

但是服务器延迟是未知的，并且每个位置都会发生变化

假设第 1 个人的服务器延迟为 122 毫秒

对于第 2 个人，服务器延迟为 234

对于人 3，服务器延迟为 444

所以我将不得不在客户端延迟页面更新

对于人 1：378 毫秒

对于人 2：266 毫秒

对于人 3：56 毫秒

我查了一下，发现有一个功能：

Sys.WebForms.PageRequestManager pageLoading Event

所以如果我能以某种方式覆盖这个函数调用的函数来更新我可以实现的页面

(我还是不知道它调用什么函数来完成客户端的更新操作)

让我们假设在里面

Sys.WebForms.PageRequestManager pageLoading Event 

updateTheChanges 函数被调用

所以如果我可以覆盖这个updateTheChanges 函数并延迟调用它，我可以实现我想要的

我需要这样的东西来覆盖更新面板的更新功能。所以我可以延迟调用这个函数

ASP.Net Webforms w/ AJAX Slow Rendering

ty

这里是网络资源文件

1. 脚本资源1：http://pastebin.com/0rSCMn3g
2. 脚本资源 2：http://pastebin.com/GvqwpPv8

下面的脚本资源 3

    function WebForm_PostBackOptions(eventTarget, eventArgument, validation, validationGroup, actionUrl, trackFocus, clientSubmit) {
    this.eventTarget = eventTarget;
    this.eventArgument = eventArgument;
    this.validation = validation;
    this.validationGroup = validationGroup;
    this.actionUrl = actionUrl;
    this.trackFocus = trackFocus;
    this.clientSubmit = clientSubmit;
}

function WebForm_DoPostBackWithOptions(options) {
    var validationResult = true;
    if (options.validation) {
        if (typeof(Page_ClientValidate) == 'function') {
            validationResult = Page_ClientValidate(options.validationGroup);
        }
    }
    if (validationResult) {
        if ((typeof(options.actionUrl) != "undefined") && (options.actionUrl != null) && (options.actionUrl.length > 0)) {
            theForm.action = options.actionUrl;
        }
        if (options.trackFocus) {
            var lastFocus = theForm.elements["__LASTFOCUS"];
            if ((typeof(lastFocus) != "undefined") && (lastFocus != null)) {
                if (typeof(document.activeElement) == "undefined") {
                    lastFocus.value = options.eventTarget;
                } else {
                    var active = document.activeElement;
                    if ((typeof(active) != "undefined") && (active != null)) {
                        if ((typeof(active.id) != "undefined") && (active.id != null) && (active.id.length > 0)) {
                            lastFocus.value = active.id;
                        } else if (typeof(active.name) != "undefined") {
                            lastFocus.value = active.name;
                        }
                    }
                }
            }
        }
    }
    if (options.clientSubmit) {
        __doPostBack(options.eventTarget, options.eventArgument);
    }
}
var __pendingCallbacks = new Array();
var __synchronousCallBackIndex = -1;

function WebForm_DoCallback(eventTarget, eventArgument, eventCallback, context, errorCallback, useAsync) {
    var postData = __theFormPostData +
        "__CALLBACKID=" + WebForm_EncodeCallback(eventTarget) +
        "&__CALLBACKPARAM=" + WebForm_EncodeCallback(eventArgument);
    if (theForm["__EVENTVALIDATION"]) {
        postData += "&__EVENTVALIDATION=" + WebForm_EncodeCallback(theForm["__EVENTVALIDATION"].value);
    }
    var xmlRequest, e;
    try {
        xmlRequest = new XMLHttpRequest();
    } catch (e) {
        try {
            xmlRequest = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {}
    }
    var setRequestHeaderMethodExists = true;
    try {
        setRequestHeaderMethodExists = (xmlRequest && xmlRequest.setRequestHeader);
    } catch (e) {}
    var callback = new Object();
    callback.eventCallback = eventCallback;
    callback.context = context;
    callback.errorCallback = errorCallback;
    callback.async = useAsync;
    var callbackIndex = WebForm_FillFirstAvailableSlot(__pendingCallbacks, callback);
    if (!useAsync) {
        if (__synchronousCallBackIndex != -1) {
            __pendingCallbacks[__synchronousCallBackIndex] = null;
        }
        __synchronousCallBackIndex = callbackIndex;
    }
    if (setRequestHeaderMethodExists) {
        xmlRequest.onreadystatechange = WebForm_CallbackComplete;
        callback.xmlRequest = xmlRequest;
        // e.g. http:
        var action = theForm.action || document.location.pathname,
            fragmentIndex = action.indexOf('#');
        if (fragmentIndex !== -1) {
            action = action.substr(0, fragmentIndex);
        }
        if (!__nonMSDOMBrowser) {
            var queryIndex = action.indexOf('?');
            if (queryIndex !== -1) {
                var path = action.substr(0, queryIndex);
                if (path.indexOf("%") === -1) {
                    action = encodeURI(path) + action.substr(queryIndex);
                }
            } else if (action.indexOf("%") === -1) {
                action = encodeURI(action);
            }
        }
        xmlRequest.open("POST", action, true);
        xmlRequest.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
        xmlRequest.send(postData);
        return;
    }
    callback.xmlRequest = new Object();
    var callbackFrameID = "__CALLBACKFRAME" + callbackIndex;
    var xmlRequestFrame = document.frames[callbackFrameID];
    if (!xmlRequestFrame) {
        xmlRequestFrame = document.createElement("IFRAME");
        xmlRequestFrame.width = "1";
        xmlRequestFrame.height = "1";
        xmlRequestFrame.frameBorder = "0";
        xmlRequestFrame.id = callbackFrameID;
        xmlRequestFrame.name = callbackFrameID;
        xmlRequestFrame.style.position = "absolute";
        xmlRequestFrame.style.top = "-100px"
        xmlRequestFrame.style.left = "-100px";
        try {
            if (callBackFrameUrl) {
                xmlRequestFrame.src = callBackFrameUrl;
            }
        } catch (e) {}
        document.body.appendChild(xmlRequestFrame);
    }
    var interval = window.setInterval(function() {
        xmlRequestFrame = document.frames[callbackFrameID];
        if (xmlRequestFrame && xmlRequestFrame.document) {
            window.clearInterval(interval);
            xmlRequestFrame.document.write("");
            xmlRequestFrame.document.close();
            xmlRequestFrame.document.write('<html><body><form method="post"><input type="hidden" name="__CALLBACKLOADSCRIPT" value="t"></form></body></html>');
            xmlRequestFrame.document.close();
            xmlRequestFrame.document.forms[0].action = theForm.action;
            var count = __theFormPostCollection.length;
            var element;
            for (var i = 0; i < count; i++) {
                element = __theFormPostCollection[i];
                if (element) {
                    var fieldElement = xmlRequestFrame.document.createElement("INPUT");
                    fieldElement.type = "hidden";
                    fieldElement.name = element.name;
                    fieldElement.value = element.value;
                    xmlRequestFrame.document.forms[0].appendChild(fieldElement);
                }
            }
            var callbackIdFieldElement = xmlRequestFrame.document.createElement("INPUT");
            callbackIdFieldElement.type = "hidden";
            callbackIdFieldElement.name = "__CALLBACKID";
            callbackIdFieldElement.value = eventTarget;
            xmlRequestFrame.document.forms[0].appendChild(callbackIdFieldElement);
            var callbackParamFieldElement = xmlRequestFrame.document.createElement("INPUT");
            callbackParamFieldElement.type = "hidden";
            callbackParamFieldElement.name = "__CALLBACKPARAM";
            callbackParamFieldElement.value = eventArgument;
            xmlRequestFrame.document.forms[0].appendChild(callbackParamFieldElement);
            if (theForm["__EVENTVALIDATION"]) {
                var callbackValidationFieldElement = xmlRequestFrame.document.createElement("INPUT");
                callbackValidationFieldElement.type = "hidden";
                callbackValidationFieldElement.name = "__EVENTVALIDATION";
                callbackValidationFieldElement.value = theForm["__EVENTVALIDATION"].value;
                xmlRequestFrame.document.forms[0].appendChild(callbackValidationFieldElement);
            }
            var callbackIndexFieldElement = xmlRequestFrame.document.createElement("INPUT");
            callbackIndexFieldElement.type = "hidden";
            callbackIndexFieldElement.name = "__CALLBACKINDEX";
            callbackIndexFieldElement.value = callbackIndex;
            xmlRequestFrame.document.forms[0].appendChild(callbackIndexFieldElement);
            xmlRequestFrame.document.forms[0].submit();
        }
    }, 10);
}

function WebForm_CallbackComplete() {
    for (var i = 0; i < __pendingCallbacks.length; i++) {
        callbackObject = __pendingCallbacks[i];
        if (callbackObject && callbackObject.xmlRequest && (callbackObject.xmlRequest.readyState == 4)) {
            if (!__pendingCallbacks[i].async) {
                __synchronousCallBackIndex = -1;
            }
            __pendingCallbacks[i] = null;
            var callbackFrameID = "__CALLBACKFRAME" + i;
            var xmlRequestFrame = document.getElementById(callbackFrameID);
            if (xmlRequestFrame) {
                xmlRequestFrame.parentNode.removeChild(xmlRequestFrame);
            }
            WebForm_ExecuteCallback(callbackObject);
        }
    }
}

function WebForm_ExecuteCallback(callbackObject) {
    var response = callbackObject.xmlRequest.responseText;
    if (response.charAt(0) == "s") {
        if ((typeof(callbackObject.eventCallback) != "undefined") && (callbackObject.eventCallback != null)) {
            callbackObject.eventCallback(response.substring(1), callbackObject.context);
        }
    } else if (response.charAt(0) == "e") {
        if ((typeof(callbackObject.errorCallback) != "undefined") && (callbackObject.errorCallback != null)) {
            callbackObject.errorCallback(response.substring(1), callbackObject.context);
        }
    } else {
        var separatorIndex = response.indexOf("|");
        if (separatorIndex != -1) {
            var validationFieldLength = parseInt(response.substring(0, separatorIndex));
            if (!isNaN(validationFieldLength)) {
                var validationField = response.substring(separatorIndex + 1, separatorIndex + validationFieldLength + 1);
                if (validationField != "") {
                    var validationFieldElement = theForm["__EVENTVALIDATION"];
                    if (!validationFieldElement) {
                        validationFieldElement = document.createElement("INPUT");
                        validationFieldElement.type = "hidden";
                        validationFieldElement.name = "__EVENTVALIDATION";
                        theForm.appendChild(validationFieldElement);
                    }
                    validationFieldElement.value = validationField;
                }
                if ((typeof(callbackObject.eventCallback) != "undefined") && (callbackObject.eventCallback != null)) {
                    callbackObject.eventCallback(response.substring(separatorIndex + validationFieldLength + 1), callbackObject.context);
                }
            }
        }
    }
}

function WebForm_FillFirstAvailableSlot(array, element) {
    var i;
    for (i = 0; i < array.length; i++) {
        if (!array[i]) break;
    }
    array[i] = element;
    return i;
}
var __nonMSDOMBrowser = (window.navigator.appName.toLowerCase().indexOf('explorer') == -1);
var __theFormPostData = "";
var __theFormPostCollection = new Array();
var __callbackTextTypes = /^(text|password|hidden|search|tel|url|email|number|range|color|datetime|date|month|week|time|datetime-local)$/i;

function WebForm_InitCallback() {
    var formElements = theForm.elements,
        count = formElements.length,
        element;
    for (var i = 0; i < count; i++) {
        element = formElements[i];
        var tagName = element.tagName.toLowerCase();
        if (tagName == "input") {
            var type = element.type;
            if ((__callbackTextTypes.test(type) || ((type == "checkbox" || type == "radio") && element.checked)) && (element.id != "__EVENTVALIDATION")) {
                WebForm_InitCallbackAddField(element.name, element.value);
            }
        } else if (tagName == "select") {
            var selectCount = element.options.length;
            for (var j = 0; j < selectCount; j++) {
                var selectChild = element.options[j];
                if (selectChild.selected == true) {
                    WebForm_InitCallbackAddField(element.name, element.value);
                }
            }
        } else if (tagName == "textarea") {
            WebForm_InitCallbackAddField(element.name, element.value);
        }
    }
}

function WebForm_InitCallbackAddField(name, value) {
    var nameValue = new Object();
    nameValue.name = name;
    nameValue.value = value;
    __theFormPostCollection[__theFormPostCollection.length] = nameValue;
    __theFormPostData += WebForm_EncodeCallback(name) + "=" + WebForm_EncodeCallback(value) + "&";
}

function WebForm_EncodeCallback(parameter) {
    if (encodeURIComponent) {
        return encodeURIComponent(parameter);
    } else {
        return escape(parameter);
    }
}
var __disabledControlArray = new Array();

function WebForm_ReEnableControls() {
    if (typeof(__enabledControlArray) == 'undefined') {
        return false;
    }
    var disabledIndex = 0;
    for (var i = 0; i < __enabledControlArray.length; i++) {
        var c;
        if (__nonMSDOMBrowser) {
            c = document.getElementById(__enabledControlArray[i]);
        } else {
            c = document.all[__enabledControlArray[i]];
        }
        if ((typeof(c) != "undefined") && (c != null) && (c.disabled == true)) {
            c.disabled = false;
            __disabledControlArray[disabledIndex++] = c;
        }
    }
    setTimeout("WebForm_ReDisableControls()", 0);
    return true;
}

function WebForm_ReDisableControls() {
    for (var i = 0; i < __disabledControlArray.length; i++) {
        __disabledControlArray[i].disabled = true;
    }
}

function WebForm_SimulateClick(element, event) {
    var clickEvent;
    if (element) {
        if (element.click) {
            element.click();
        } else {
            clickEvent = document.createEvent("MouseEvents");
            clickEvent.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
            if (!element.dispatchEvent(clickEvent)) {
                return true;
            }
        }
        event.cancelBubble = true;
        if (event.stopPropagation) {
            event.stopPropagation();
        }
        return false;
    }
    return true;
}

function WebForm_FireDefaultButton(event, target) {
    if (event.keyCode == 13) {
        var src = event.srcElement || event.target;
        if (src &&
            ((src.tagName.toLowerCase() == "input") &&
                (src.type.toLowerCase() == "submit" || src.type.toLowerCase() == "button")) ||
            ((src.tagName.toLowerCase() == "a") &&
                (src.href != null) && (src.href != "")) ||
            (src.tagName.toLowerCase() == "textarea")) {
            return true;
        }
        var defaultButton;
        if (__nonMSDOMBrowser) {
            defaultButton = document.getElementById(target);
        } else {
            defaultButton = document.all[target];
        }
        if (defaultButton) {
            return WebForm_SimulateClick(defaultButton, event);
        }
    }
    return true;
}

function WebForm_GetScrollX() {
    if (__nonMSDOMBrowser) {
        return window.pageXOffset;
    } else {
        if (document.documentElement && document.documentElement.scrollLeft) {
            return document.documentElement.scrollLeft;
        } else if (document.body) {
            return document.body.scrollLeft;
        }
    }
    return 0;
}

function WebForm_GetScrollY() {
    if (__nonMSDOMBrowser) {
        return window.pageYOffset;
    } else {
        if (document.documentElement && document.documentElement.scrollTop) {
            return document.documentElement.scrollTop;
        } else if (document.body) {
            return document.body.scrollTop;
        }
    }
    return 0;
}

function WebForm_SaveScrollPositionSubmit() {
    if (__nonMSDOMBrowser) {
        theForm.elements['__SCROLLPOSITIONY'].value = window.pageYOffset;
        theForm.elements['__SCROLLPOSITIONX'].value = window.pageXOffset;
    } else {
        theForm.__SCROLLPOSITIONX.value = WebForm_GetScrollX();
        theForm.__SCROLLPOSITIONY.value = WebForm_GetScrollY();
    }
    if ((typeof(this.oldSubmit) != "undefined") && (this.oldSubmit != null)) {
        return this.oldSubmit();
    }
    return true;
}

function WebForm_SaveScrollPositionOnSubmit() {
    theForm.__SCROLLPOSITIONX.value = WebForm_GetScrollX();
    theForm.__SCROLLPOSITIONY.value = WebForm_GetScrollY();
    if ((typeof(this.oldOnSubmit) != "undefined") && (this.oldOnSubmit != null)) {
        return this.oldOnSubmit();
    }
    return true;
}

function WebForm_RestoreScrollPosition() {
    if (__nonMSDOMBrowser) {
        window.scrollTo(theForm.elements['__SCROLLPOSITIONX'].value, theForm.elements['__SCROLLPOSITIONY'].value);
    } else {
        window.scrollTo(theForm.__SCROLLPOSITIONX.value, theForm.__SCROLLPOSITIONY.value);
    }
    if ((typeof(theForm.oldOnLoad) != "undefined") && (theForm.oldOnLoad != null)) {
        return theForm.oldOnLoad();
    }
    return true;
}

function WebForm_TextBoxKeyHandler(event) {
    if (event.keyCode == 13) {
        var target;
        if (__nonMSDOMBrowser) {
            target = event.target;
        } else {
            target = event.srcElement;
        }
        if ((typeof(target) != "undefined") && (target != null)) {
            if (typeof(target.onchange) != "undefined") {
                target.onchange();
                event.cancelBubble = true;
                if (event.stopPropagation) event.stopPropagation();
                return false;
            }
        }
    }
    return true;
}

function WebForm_TrimString(value) {
    return value.replace(/^\s+|\s+$/g, '')
}

function WebForm_AppendToClassName(element, className) {
    var currentClassName = ' ' + WebForm_TrimString(element.className) + ' ';
    className = WebForm_TrimString(className);
    var index = currentClassName.indexOf(' ' + className + ' ');
    if (index === -1) {
        element.className = (element.className === '') ? className : element.className + ' ' + className;
    }
}

function WebForm_RemoveClassName(element, className) {
    var currentClassName = ' ' + WebForm_TrimString(element.className) + ' ';
    className = WebForm_TrimString(className);
    var index = currentClassName.indexOf(' ' + className + ' ');
    if (index >= 0) {
        element.className = WebForm_TrimString(currentClassName.substring(0, index) + ' ' +
            currentClassName.substring(index + className.length + 1, currentClassName.length));
    }
}

function WebForm_GetElementById(elementId) {
    if (document.getElementById) {
        return document.getElementById(elementId);
    } else if (document.all) {
        return document.all[elementId];
    } else return null;
}

function WebForm_GetElementByTagName(element, tagName) {
    var elements = WebForm_GetElementsByTagName(element, tagName);
    if (elements && elements.length > 0) {
        return elements[0];
    } else return null;
}

function WebForm_GetElementsByTagName(element, tagName) {
    if (element && tagName) {
        if (element.getElementsByTagName) {
            return element.getElementsByTagName(tagName);
        }
        if (element.all && element.all.tags) {
            return element.all.tags(tagName);
        }
    }
    return null;
}

function WebForm_GetElementDir(element) {
    if (element) {
        if (element.dir) {
            return element.dir;
        }
        return WebForm_GetElementDir(element.parentNode);
    }
    return "ltr";
}

function WebForm_GetElementPosition(element) {
    var result = new Object();
    result.x = 0;
    result.y = 0;
    result.width = 0;
    result.height = 0;
    if (element.offsetParent) {
        result.x = element.offsetLeft;
        result.y = element.offsetTop;
        var parent = element.offsetParent;
        while (parent) {
            result.x += parent.offsetLeft;
            result.y += parent.offsetTop;
            var parentTagName = parent.tagName.toLowerCase();
            if (parentTagName != "table" &&
                parentTagName != "body" &&
                parentTagName != "html" &&
                parentTagName != "div" &&
                parent.clientTop &&
                parent.clientLeft) {
                result.x += parent.clientLeft;
                result.y += parent.clientTop;
            }
            parent = parent.offsetParent;
        }
    } else if (element.left && element.top) {
        result.x = element.left;
        result.y = element.top;
    } else {
        if (element.x) {
            result.x = element.x;
        }
        if (element.y) {
            result.y = element.y;
        }
    }
    if (element.offsetWidth && element.offsetHeight) {
        result.width = element.offsetWidth;
        result.height = element.offsetHeight;
    } else if (element.style && element.style.pixelWidth && element.style.pixelHeight) {
        result.width = element.style.pixelWidth;
        result.height = element.style.pixelHeight;
    }
    return result;
}

function WebForm_GetParentByTagName(element, tagName) {
    var parent = element.parentNode;
    var upperTagName = tagName.toUpperCase();
    while (parent && (parent.tagName.toUpperCase() != upperTagName)) {
        parent = parent.parentNode ? parent.parentNode : parent.parentElement;
    }
    return parent;
}

function WebForm_SetElementHeight(element, height) {
    if (element && element.style) {
        element.style.height = height + "px";
    }
}

function WebForm_SetElementWidth(element, width) {
    if (element && element.style) {
        element.style.width = width + "px";
    }
}

function WebForm_SetElementX(element, x) {
    if (element && element.style) {
        element.style.left = x + "px";
    }
}

function WebForm_SetElementY(element, y) {
    if (element && element.style) {
        element.style.top = y + "px";
    }
}

Answer 1

这是一种在不冻结用户界面的情况下延迟 UpdatePanel 刷新的方法：

1. 在 pageLoading 事件处理程序中，保存要更新的面板的 ID 和以前的 HTML
2. 在pageLoad 事件处理程序中，保存面板的新 HTML，但用旧的替换它
3. 延迟到期后，在更新的面板中设置新的 HTML

这是客户端代码：

<script type="text/javascript">
    var updateTime = 0;
    var updatedPanelArray = [];

    function setUpdateTime() {
        updateTime = new Date(Date.now() + 500);
    }

    function pageLoading(sender, e) {
        updatedPanelArray.length = 0;
        var panels = e.get_panelsUpdating();
        for (var i = 0; i < panels.length; i++) {
            var pnl = panels[i];
            updatedPanelArray.push({ id: pnl.id, oldHTML: pnl.innerHTML });
        }
    }

    function pageLoad(sender, e) {
        if (e.get_isPartialLoad()) {
            for (var i = 0; i < updatedPanelArray.length; i++) {
                var updatedPanel = updatedPanelArray[i];
                var pnl = document.getElementById(updatedPanel.id);
                updatedPanel.newHTML = pnl.innerHTML;
                pnl.innerHTML = updatedPanel.oldHTML;
                setTimeout(refreshUpdatePanel, updateTime - Date.now());
            }
        }
    }

    function refreshUpdatePanel() {
        for (var i = 0; i < updatedPanelArray.length; i++) {
            var updatedPanel = updatedPanelArray[i];
            var pnl = document.getElementById(updatedPanel.id);
            pnl.innerHTML = updatedPanel.newHTML;
        }
    }

    Sys.WebForms.PageRequestManager.getInstance().add_pageLoading(pageLoading);
</script>

在触发异步回发之前设置更新时间：

<asp:UpdatePanel runat="server" UpdateMode="Conditional">
    <ContentTemplate>
        <asp:Label ID="lblUpdatePanel1" runat="server" />
        <asp:Button ID="btnUpdatePanel" runat="server" OnClientClick="setUpdateTime();" OnClick="btnUpdatePanel_Click" />
    </ContentTemplate>
</asp:UpdatePanel>

可以在代码隐藏中使用以下事件处理程序进行测试（建议：在Javascript代码中将延迟设置为5000毫秒以使其明显）：

protected void btnUpdatePanel_Click(object sender, EventArgs e)
{
    lblUpdatePanel1.Text = DateTime.Now.ToString();
}

Answer 2

如果您不介意用户界面在等待时被冻结，您可以通过让pageLoad 事件处理程序保持忙碌直到延迟到期来延迟刷新：

<script type="text/javascript">
    var updateTime = 0;

    function setUpdateTime() {
        updateTime = new Date(Date.now() + 500);
    }

    function pageLoad(sender, e) {
        if (e.get_isPartialLoad()) {
            while (Date.now() < updateTime) { 
                // Loop until the delay expires
            }
        }
    }
</script>

可以在触发异步回发之前初始化更新时间：

<asp:UpdatePanel runat="server" UpdateMode="Conditional">
    <ContentTemplate>
        ...
        <asp:Button ID="btn1" runat="server" OnClientClick="setUpdateTime();" ... />
    </ContentTemplate>
</asp:UpdatePanel>

Answer 3

使用UpdatePanel.UpdateMode 属性获取或设置一个值，该值指示UpdatePanel 控件的内容何时更新。更多详情请访问this链接。

Answer 4

您可以延迟服务器端，因此所有延迟对每个人来说都差不多。

如果这不是一个选项，您可以在更新面板（或其他地方）内设置一个隐藏字段。处理更新的函数（在服务器端）将计算执行时间，并在完成之前更新此隐藏字段。现在回到客户端，检查该字段的值并计算该值与您的 500 毫秒之间的差异。您可以使用日期时间或毫秒。

这不是最漂亮的解决方案，但恕我直言，这不是人们想要处理的常见问题（事实上，我认为您不应该将更快的响应延迟到最慢的响应）