我有下面的样本html,有一个DIV有100%的宽度。它包含了一些元素。在执行窗口调整大小时,内部元素可能会被重新定位,div的尺寸可能会改变。我在问是否有可能挂钩div的维度变化事件?以及如何做到这一点?我目前绑定回调函数到目标DIV上的jQuery调整大小事件,但是,没有输出控制台日志,如下所示:
<html>
<head>
<script type="text/javascript" language="javascript" src="http://code.jquery.com/jquery-1.6.1.min.js"></script>
<script type="text/javascript" language="javascript">
$('#test_div').bind('resize', function(){
console.log('resized');
});
</script>
</head>
<body>
<div id="test_div" style="width: 100%; min-height: 30px; border: 1px dashed pink;">
<input type="button" value="button 1" />
<input type="button" value="button 2" />
<input type="button" value="button 3" />
</div>
</body>
</html>
一个更新的标准是Resize Observer api,有很好的浏览器支持。
函数输出大小() {
宽度.值 = 文本框偏移宽度
高度.值 = 文本框偏移高度
}
输出大小()
new ResizeObserver (outputsize).observe(textbox)
宽度:<输出 id=“宽度”>0</output><br>
高度:<输出 id=“高度”>0</output><br>
<textarea id=“textbox”>调整我</textarea><br>的大小
调整观察者
文档:https://developer.mozilla.org/en-US/docs/Web/API/Resize_Observer_API
规范:https://wicg.github.io/ResizeObserver
当前支持:http://caniuse.com/#feat=resizeobserver
填充物:https://github.com/pelotoncycle/resize-observer
https://github.com/que-etc/resize-observer-polyfill
https://github.com/juggle/resize-observer
这篇博文帮助我有效地检测DOM元素的大小变化。
http://www.backalleycoder.com/2013/03/18/cross-browser-event-based-element-resize-detection/
如何使用这段代码…
AppConfig.addResizeListener(document.getElementById('id'), function () {
//Your code to execute on resize.
});
示例使用的打包代码…
var AppConfig = AppConfig || {};
AppConfig.ResizeListener = (function () {
var attachEvent = document.attachEvent;
var isIE = navigator.userAgent.match(/Trident/);
var requestFrame = (function () {
var raf = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame ||
function (fn) { return window.setTimeout(fn, 20); };
return function (fn) { return raf(fn); };
})();
var cancelFrame = (function () {
var cancel = window.cancelAnimationFrame || window.mozCancelAnimationFrame || window.webkitCancelAnimationFrame ||
window.clearTimeout;
return function (id) { return cancel(id); };
})();
function resizeListener(e) {
var win = e.target || e.srcElement;
if (win.__resizeRAF__) cancelFrame(win.__resizeRAF__);
win.__resizeRAF__ = requestFrame(function () {
var trigger = win.__resizeTrigger__;
trigger.__resizeListeners__.forEach(function (fn) {
fn.call(trigger, e);
});
});
}
function objectLoad(e) {
this.contentDocument.defaultView.__resizeTrigger__ = this.__resizeElement__;
this.contentDocument.defaultView.addEventListener('resize', resizeListener);
}
AppConfig.addResizeListener = function (element, fn) {
if (!element.__resizeListeners__) {
element.__resizeListeners__ = [];
if (attachEvent) {
element.__resizeTrigger__ = element;
element.attachEvent('onresize', resizeListener);
} else {
if (getComputedStyle(element).position === 'static') element.style.position = 'relative';
var obj = element.__resizeTrigger__ = document.createElement('object');
obj.setAttribute('style', 'display: block; position: absolute; top: 0; left: 0; height: 100%; width: 100%; overflow: hidden; pointer-events: none; z-index: -1;');
obj.__resizeElement__ = element;
obj.onload = objectLoad;
obj.type = 'text/html';
if (isIE) element.appendChild(obj);
obj.data = 'about:blank';
if (!isIE) element.appendChild(obj);
}
}
element.__resizeListeners__.push(fn);
};
AppConfig.removeResizeListener = function (element, fn) {
element.__resizeListeners__.splice(element.__resizeListeners__.indexOf(fn), 1);
if (!element.__resizeListeners__.length) {
if (attachEvent) element.detachEvent('onresize', resizeListener);
else {
element.__resizeTrigger__.contentDocument.defaultView.removeEventListener('resize', resizeListener);
element.__resizeTrigger__ = !element.removeChild(element.__resizeTrigger__);
}
}
}
})();
注意:AppConfig是我用于组织可重用函数的名称空间/对象。请随意搜索并替换任何您想要的名称。
下面是@nkron的简化版本的解决方案,适用于单个元素(而不是@nkron的答案中的元素数组,我不需要复杂性)。
function onResizeElem(element, callback) {
// Save the element we are watching
onResizeElem.watchedElementData = {
element: element,
offsetWidth: element.offsetWidth,
offsetHeight: element.offsetHeight,
callback: callback
};
onResizeElem.checkForChanges = function() {
const data = onResizeElem.watchedElementData;
if (data.element.offsetWidth !== data.offsetWidth || data.element.offsetHeight !== data.offsetHeight) {
data.offsetWidth = data.element.offsetWidth;
data.offsetHeight = data.element.offsetHeight;
data.callback();
}
};
// Listen to the window resize event
window.addEventListener('resize', onResizeElem.checkForChanges);
// Listen to the element being checked for width and height changes
onResizeElem.observer = new MutationObserver(onResizeElem.checkForChanges);
onResizeElem.observer.observe(document.body, {
attributes: true,
childList: true,
characterData: true,
subtree: true
});
}
事件监听器和观察者可以通过以下方式删除:
window.removeEventListener('resize', onResizeElem.checkForChanges);
onResizeElem.observer.disconnect();
这几乎是顶部答案的精确副本,但不是链接,它只是重要的代码的一部分,翻译成IMO更易读,更容易理解。其他一些小的改变包括使用cloneNode(),和不把html放入js字符串。很小的东西,但是你可以复制粘贴它就可以了。
它的工作方式是让两个看不见的div填充你正在观看的元素,然后在每个div中设置一个触发器,并设置一个滚动位置,如果大小发生变化,将导致触发滚动变化。
所有真正的荣誉都属于Marc J,但如果你只是在寻找相关的代码,这里是:
window.El = {}
El.resizeSensorNode = undefined;
El.initResizeNode = function() {
var fillParent = "display: block; position: absolute; left: 0; top: 0; right: 0; bottom: 0; overflow: hidden; z-index: -1; visibility: hidden;";
var triggerStyle = "position: absolute; left: 0; top: 0; transition: 0s;";
var resizeSensor = El.resizeSensorNode = document.createElement("resizeSensor");
resizeSensor.style = fillParent;
var expandSensor = document.createElement("div");
expandSensor.style = fillParent;
resizeSensor.appendChild(expandSensor);
var trigger = document.createElement("div");
trigger.style = triggerStyle;
expandSensor.appendChild(trigger);
var shrinkSensor = expandSensor.cloneNode(true);
shrinkSensor.firstChild.style = triggerStyle + " width: 200%; height: 200%";
resizeSensor.appendChild(shrinkSensor);
}
El.onSizeChange = function(domNode, fn) {
if (!domNode) return;
if (domNode.resizeListeners) {
domNode.resizeListeners.push(fn);
return;
}
domNode.resizeListeners = [];
domNode.resizeListeners.push(fn);
if(El.resizeSensorNode == undefined)
El.initResizeNode();
domNode.resizeSensor = El.resizeSensorNode.cloneNode(true);
domNode.appendChild(domNode.resizeSensor);
var expand = domNode.resizeSensor.firstChild;
var expandTrigger = expand.firstChild;
var shrink = domNode.resizeSensor.childNodes[1];
var reset = function() {
expandTrigger.style.width = '100000px';
expandTrigger.style.height = '100000px';
expand.scrollLeft = 100000;
expand.scrollTop = 100000;
shrink.scrollLeft = 100000;
shrink.scrollTop = 100000;
};
reset();
var hasChanged, frameRequest, newWidth, newHeight;
var lastWidth = domNode.offsetWidth;
var lastHeight = domNode.offsetHeight;
var onResized = function() {
frameRequest = undefined;
if (!hasChanged) return;
lastWidth = newWidth;
lastHeight = newHeight;
var listeners = domNode.resizeListeners;
for(var i = 0; listeners && i < listeners.length; i++)
listeners[i]();
};
var onScroll = function() {
newWidth = domNode.offsetWidth;
newHeight = domNode.offsetHeight;
hasChanged = newWidth != lastWidth || newHeight != lastHeight;
if (hasChanged && !frameRequest) {
frameRequest = requestAnimationFrame(onResized);
}
reset();
};
expand.addEventListener("scroll", onScroll);
shrink.addEventListener("scroll", onScroll);
}