Javascript中动态计算溢出量
我有一个conatiner div,它的高度和宽度都是相对固定的。我想通过Javascript计算出它的子元素在顶部、右侧、底部和左侧方向上超出容器div边缘的程度(如果有的话)。任何帮助都将不胜感激 这是Javascript中动态计算溢出量,javascript,Javascript,我有一个conatiner div,它的高度和宽度都是相对固定的。我想通过Javascript计算出它的子元素在顶部、右侧、底部和左侧方向上超出容器div边缘的程度(如果有的话)。任何帮助都将不胜感激 这是top的代码: var myDivEl = document.getElementById("my-div"); var divTop = myDivEl.getBoundingClientRect().top; var descendants = myDivEl.getElementsBy
top
的代码:
var myDivEl = document.getElementById("my-div");
var divTop = myDivEl.getBoundingClientRect().top;
var descendants = myDivEl.getElementsByTagName("*");
var tops = [];
for (var i = 0, descendant; descendant = descendants[i]; ++i) {
tops.push(descendant.getBoundingClientRect().top);
}
var minTop = Math.min.apply(Math, tops);
var diff = divTop - minTop;
更一般地说:
function getBoundingClientRectDiff(el, propName, minOrMax) {
var propValue = el.getBoundingClientRect()[propName];
var descendants = myDivEl.getElementsByTagName("*");
var descendantPropValues = [];
for (var i = 0, descendant; descendant = descendants[i]; ++i) {
descendantPropValues.push(descendant.getBoundingClientRect()[propName]);
}
var extremePropValue = Math[minOrMax].apply(Math, descendantPropValues);
return minOrMax === "Max" ? extremePropValue - propValue
: propValue - extremePropValue;
}
function getBoundingClientRectDiffs(el) {
return {
top: getBoundingClientRectDiff(el, "top", "Min"),
right: getBoundingClientRectDiff(el, "right", "Max"),
bottom: getBoundingClientRectDiff(el, "bottom", "Max"),
left: getBoundingClientRectDiff(el, "left", "Min")
};
}
// use like so:
var diffs = getBoundingClientRectDiffs(myDivEl);
console.log(diffs.top, diffs.right, diffs.bottom, diffs.left);
您还可以获得元素的宽度和scrollWidth或高度和scrollHeight属性之间的差异。Domenic,我如何调整它以考虑子节点的显示属性?基本上,如果子级设置为显示:无;我不想在计算中包含它或它的任何子节点。@VinnyD,您应该在
for
循环中添加if(genderant.style.display!=“none”){}
,包装genderantpropvalues.push(…)
。