我有这个svg“代码”
<svg xmlns="http://www.w3.org/2000/svg" width="20" height="34">
<path transform="rotate(0 10 17)" fill="#6699FF" d="M 0.06,25.03 C 0.06,25.03 4.06,20.97 4.06,20.97 4.06,20.97 3.97,5.06 3.97,5.06 3.97,5.06 9.94,0.03 9.94,0.03 9.94,0.03 15.78,5.09 15.78,5.09 15.78,5.09 16.03,21.06 16.03,21.06 16.03,21.06 19.94,25.00 19.94,25.00 19.94,25.00 19.97,30.09 19.97,30.09 19.97,30.09 10.06,20.97 10.06,20.97 10.06,20.97 10.05,23.00 10.05,23.00 10.05,23.00 19.91,32.03 19.91,32.03 19.91,32.03 19.94,33.97 19.94,33.97 19.94,33.97 17.97,33.97 17.97,33.97 17.97,33.97 10.03,26.94 10.03,26.94 10.03,26.94 10.05,29.01 10.05,29.01 10.05,29.01 15.94,34.00 15.94,34.00 15.94,34.00 12.00,33.94 12.00,33.94 12.00,33.94 10.00,32.00 10.00,32.00 10.00,32.00 8.00,34.03 8.00,34.03 8.00,34.03 4.00,34.00 4.00,34.00 4.00,34.00 9.97,29.01 9.97,29.01 9.97,29.01 9.97,26.94 9.97,26.94 9.97,26.94 2.00,33.96 2.00,33.96 2.00,33.96 0.00,33.98 0.00,33.98 0.00,33.98 0.02,32.00 0.02,32.00 0.02,32.00 9.96,23.00 9.96,23.00 9.96,23.00 9.95,20.98 9.95,20.98 9.95,20.98 0.00,30.00 0.00,30.00 0.00,30.00 0.06,25.03 0.06,25.03 Z" />
<path transform="rotate(0 10 17) translate(0 0)" fill="white" d="M 8.04,17.04 C 8.04,17.04 7.98,11.04 7.98,11.04 7.98,11.04 5.00,11.00 5.00,11.00 5.00,11.00 10.00,6.04 10.00,6.04 10.00,6.04 14.96,11.02 14.96,11.02 14.96,11.02 12.02,11.04 12.02,11.04 12.02,11.04 12.02,17.04 12.02,17.04 12.02,17.04 8.04,17.04 8.04,17.04 Z" />
</svg>
我正在尝试旋转这张“图片”，（我需要将其旋转360度）。
当我将rotate(0 10 17)更改为rotate(90 10 17)时，它会被删除。那是因为我没有从图像中心旋转它。
我尝试使用这个公式计算中心，但我无法自己设法
x = 34; y = 20; o = 4.71238898 //(degrees to radiants) ;
a = Math.abs(x * Math.sin(o)) + Math.abs(y * Math.cos(o));
b = Math.abs(x * Math.cos(o)) + Math.abs(y * Math.sin(o));
我对那些数学/ svg问题非常不满意，我希望有人可以帮助我。
由于
答案 0 :(得分：2)
旋转中心是正确的。但麻烦的是现在轮换了，你的图形不再是20x34，它是34x20。
所以你要做的第一件事就是更新宽度和高度。
<svg xmlns="http://www.w3.org/2000/svg" width="34" height="20">
当然，这不是最终的解决方案，因为这个新的34x20 SVG的中心位于旧的20x34中心的不同位置。一种解决方案是设计出一个可以工作的不同旋转中心，使图形旋转到新矩形的正确位置。
这有点棘手。幸运的是，有一种更简单的方法。我们可以在SVG中添加一个viewBox来告诉浏览器旋转符号所占区域的大小。浏览器会为我们重新定位。
viewBox属性中的四个值为：
<leftX> <topY> <width> <height>
我们已经知道了宽度和高度（34和20），所以我们只需要计算左和顶部的坐标。这些显然只是旋转中心的宽度和高度的一半。
leftX = 10 - (newWidth / 2)
= 10 - 17
= -7
topY = 17 - (newHeight / 2)
= 17 - 10
= 7
因此viewBox属性必须为"-7 7 34 20"。
<svg xmlns="http://www.w3.org/2000/svg" width="34" height="20" viewBox="-7 7 34 20">
<path transform="rotate(90 10 17)" fill="#6699FF" d="M 0.06,25.03 C 0.06,25.03 4.06,20.97 4.06,20.97 4.06,20.97 3.97,5.06 3.97,5.06 3.97,5.06 9.94,0.03 9.94,0.03 9.94,0.03 15.78,5.09 15.78,5.09 15.78,5.09 16.03,21.06 16.03,21.06 16.03,21.06 19.94,25.00 19.94,25.00 19.94,25.00 19.97,30.09 19.97,30.09 19.97,30.09 10.06,20.97 10.06,20.97 10.06,20.97 10.05,23.00 10.05,23.00 10.05,23.00 19.91,32.03 19.91,32.03 19.91,32.03 19.94,33.97 19.94,33.97 19.94,33.97 17.97,33.97 17.97,33.97 17.97,33.97 10.03,26.94 10.03,26.94 10.03,26.94 10.05,29.01 10.05,29.01 10.05,29.01 15.94,34.00 15.94,34.00 15.94,34.00 12.00,33.94 12.00,33.94 12.00,33.94 10.00,32.00 10.00,32.00 10.00,32.00 8.00,34.03 8.00,34.03 8.00,34.03 4.00,34.00 4.00,34.00 4.00,34.00 9.97,29.01 9.97,29.01 9.97,29.01 9.97,26.94 9.97,26.94 9.97,26.94 2.00,33.96 2.00,33.96 2.00,33.96 0.00,33.98 0.00,33.98 0.00,33.98 0.02,32.00 0.02,32.00 0.02,32.00 9.96,23.00 9.96,23.00 9.96,23.00 9.95,20.98 9.95,20.98 9.95,20.98 0.00,30.00 0.00,30.00 0.00,30.00 0.06,25.03 0.06,25.03 Z" />
<path transform="rotate(90 10 17) translate(0 0)" fill="white" d="M 8.04,17.04 C 8.04,17.04 7.98,11.04 7.98,11.04 7.98,11.04 5.00,11.00 5.00,11.00 5.00,11.00 10.00,6.04 10.00,6.04 10.00,6.04 14.96,11.02 14.96,11.02 14.96,11.02 12.02,11.04 12.02,11.04 12.02,11.04 12.02,17.04 12.02,17.04 12.02,17.04 8.04,17.04 8.04,17.04 Z" />
</svg>
<强>更新
如果你需要做任意角度，那么有一个更好的方法，使用Javascript。
getBBox()以获取其内容的尺寸。viewBox和width以及＆＃39; height`
var angle = 145; // degrees
var mysvg = document.getElementById("mysvg");
var paths = mysvg.getElementsByTagName("path");
// Apply a transform attribute to each path
for (var i=0; i<paths.length; i++) {
paths[i].setAttribute("transform", "rotate("+angle+",10,17)");
}
// Now that the paths have been rotated, get the bounding box
// of the SVG contents
var bbox = mysvg.getBBox();
// Update the viewBox from the bounds
mysvg.setAttribute("viewBox", bbox.x + " " + bbox.y + " " +
bbox.width +" "+ bbox.height);
// Update the width and height
mysvg.setAttribute("width", bbox.width + "px");
mysvg.setAttribute("height", bbox.height + "px");<svg id="mysvg" xmlns="http://www.w3.org/2000/svg" width="20" height="34">
<path fill="#6699FF" d="M 0.06,25.03 C 0.06,25.03 4.06,20.97 4.06,20.97 4.06,20.97 3.97,5.06 3.97,5.06 3.97,5.06 9.94,0.03 9.94,0.03 9.94,0.03 15.78,5.09 15.78,5.09 15.78,5.09 16.03,21.06 16.03,21.06 16.03,21.06 19.94,25.00 19.94,25.00 19.94,25.00 19.97,30.09 19.97,30.09 19.97,30.09 10.06,20.97 10.06,20.97 10.06,20.97 10.05,23.00 10.05,23.00 10.05,23.00 19.91,32.03 19.91,32.03 19.91,32.03 19.94,33.97 19.94,33.97 19.94,33.97 17.97,33.97 17.97,33.97 17.97,33.97 10.03,26.94 10.03,26.94 10.03,26.94 10.05,29.01 10.05,29.01 10.05,29.01 15.94,34.00 15.94,34.00 15.94,34.00 12.00,33.94 12.00,33.94 12.00,33.94 10.00,32.00 10.00,32.00 10.00,32.00 8.00,34.03 8.00,34.03 8.00,34.03 4.00,34.00 4.00,34.00 4.00,34.00 9.97,29.01 9.97,29.01 9.97,29.01 9.97,26.94 9.97,26.94 9.97,26.94 2.00,33.96 2.00,33.96 2.00,33.96 0.00,33.98 0.00,33.98 0.00,33.98 0.02,32.00 0.02,32.00 0.02,32.00 9.96,23.00 9.96,23.00 9.96,23.00 9.95,20.98 9.95,20.98 9.95,20.98 0.00,30.00 0.00,30.00 0.00,30.00 0.06,25.03 0.06,25.03 Z" />
<path fill="white" d="M 8.04,17.04 C 8.04,17.04 7.98,11.04 7.98,11.04 7.98,11.04 5.00,11.00 5.00,11.00 5.00,11.00 10.00,6.04 10.00,6.04 10.00,6.04 14.96,11.02 14.96,11.02 14.96,11.02 12.02,11.04 12.02,11.04 12.02,11.04 12.02,17.04 12.02,17.04 12.02,17.04 8.04,17.04 8.04,17.04 Z" />
</svg>