javascript - 将 DIV 排成一圈，并朝外旋转

Question

基本上我已经设法将我的 DIV 元素布置成圆形，但我还没有设法计算出如何计算旋转度数需要让它们从圆心向外。

$(document).ready(function(){
                var elems = document.getElementsByClassName('test_box');

                var increase = Math.PI * 2 / elems.length;
                var x = 0, y = 0, angle = 0;

                for (var i = 0; i < elems.length; i++) {
                    var elem = elems[i];
                    // modify to change the radius and position of a circle
                    x = 400 * Math.cos(angle) + 700;
                    y = 400 * Math.sin(angle) + 700;
                    elem.style.position = 'absolute';
                    elem.style.left = x + 'px';
                    elem.style.top = y + 'px';
                    //need to work this part out
                    var rot = 45;
                    elem.style['-moz-transform'] = "rotate("+rot+"deg)";
                    elem.style.MozTransform = "rotate("+rot+"deg)";
                    elem.style['-webkit-transform'] = "rotate("+rot+"deg)";
                    elem.style['-o-transform'] = "rotate("+rot+"deg)";
                    elem.style['-ms-transform'] = "rotate("+rot+"deg)";
                    angle += increase;
                    console.log(angle);
                }
            });

有没有人知道我该怎么做。

干杯-C

Answer 1

请注意，rot 取决于angle，除了angle 是以弧度为单位。

DRY，所以要么从 Angular 转换为旋转:

// The -90 (degrees) makes the text face outwards.
var rot = angle * 180 / Math.PI - 90;

或者在设置样式时直接使用angle(但以弧度为单位)，去掉rot的声明:

// The -0.5*Math.PI (radians) makes the text face outwards.
elem.style.MozTransform = "rotate("+(angle-0.5*Math.PI)+"rad)";