JS控制SVG缩放+鼠标控制事件

话不多说，直接上代码吧，不行你砍我。。。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>js控制SVG缩放</title>
</head>
<body>
    <svg id="svg" style="background-color: #FAFAFA;">
        <g id="svgPanel">
            <g id="grid"></g>
            <defs>
                <path id="path1" d="M300,200 a1,1 0 0,0 100,0" />
            </defs>
            <text x="10" y="100" style="fill:green;">
                <textPath xlink:href="#path1">啦啦啦啦啦啦啦啦啦啦</textPath>
            </text>
        </g>
    </svg>
    <button onclick="zoom(1.1)">放大</button>
    <button onclick="zoom(0.9)">缩小</button>

    <script type="text/javascript">
        var svg = document.getElementById('svg');
        var svgPanel = document.getElementById('svgPanel');
        var gridSvg = document.getElementById('grid');
        var width = 800;  // 设置svg整体的宽和高
        var height = 400;
        var gridLength = 20;  // 定义网格的大小
        svg.setAttribute('width', width);
        svg.setAttribute('height', height);

        // 绘制网格
        drawGrid(gridSvg, width, height, gridLength);
        /*
            * 绘制网络
            * @param {Object} svgBackground 绘制网格对象
            * @param {Int} winWidth 区域宽度
            * @param {Int} winHeight 区域高度
            * @param {Int} gridLength 网格大小
        */
        function drawGrid(svgBackground, winWidth, winHeight, gridLength) {
            var childs = gridSvg.childNodes;
            // 删除之前的网格节点,便于绘制
            for (var i = childs.length - 1; i>= 0; i--){
                svgBackground.removeChild(childs.item(i));
            }
            for (var j = 0,len = Math.ceil(winWidth / gridLength); j < len; j++){
                var attrs = {
                    x1 : j * gridLength,
                    y1 : 0,
                    x2 : j * gridLength,
                    y2 : winHeight,
                    stroke : '#add'
                };
                var line = resetSvg('line', attrs);
                svgBackground.appendChild(line);
            }
            for (var k = 0, len2 = Math.ceil(winHeight / gridLength); k <= len2; k++){
                var attrs2 = {
                    x1 : 0,
                    y1 : k * gridLength,
                    x2 : winWidth,
                    y2 : k * gridLength,
                    stroke : '#add'
                };
                var line2 = resetSvg('line', attrs2);
                svgBackground.appendChild(line2)
            }
        }
        /*
            * js创建svg元素
            * @param {String} tag svg的标签名
            * @param {Object} svg元素的属性
        */
        function resetSvg(tag, attrs) {
            var element = document.createElementNS('http://www.w3.org/2000/svg', tag);
            for (var g in attrs){
                element.setAttribute(g, attrs[g])
            }
            return element;
        }
        /*
            * svg缩放
            * {Float} num 收缩的倍数
        */
        var scale = 1;
        function zoom(num) {
            scale *= num;
            svgPanel.setAttribute('transform', 'scale(' + scale + ')');
            drawGrid(gridSvg, width*(1/scale), height*(1/scale), gridLength);
        }
        // 绑定鼠标滑轮
        if (document.addEventListener){
            document.addEventListener('DOMMouseScroll', scrollZoom, false);
        }
        window.onmousewheel = document.onmousewhell = scrollZoom;
        /*
        * 滑轮滚动处理事件，向上滚动放大
        * {Object} e 事件对象
        */
        function scrollZoom(e) {
            e = e || window.event;
            // e.detail用来兼容FireFox
            e.wheelDelta>0 || e.detail>0?zoom(1.1):zoom(0.9);
        }
    </script>
</body>
</html>

 

posted @ 2019-10-28 17:16  .why  阅读(3511)  评论(1)  编辑  收藏  举报
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