我想使用SVG圆形元素创建一个甜甜圈图表,方法是设置stroke-dasharray和change stroke-dashoffset. SVG元素需要旋转270(或-90)度才能使图表“bar”从顶部开始.这是代码：
http://jsfiddle.net/q3wb6gkq/
旋转角度使用transform =“rotation(270,80,80)”中的第一个数字指定.
问题是：当在iOS 10上的Safari中查看时,不会应用此旋转.其实设置90度,180度或270度旋转没有任何效果.同样的角度也是负的(例如-90)也不适用.
以下是iOS 10.0.1中Safari的上述小提琴的截图：
而在iOS 9.3.5的Safari中,这是一样的小提琴：
作为解决方法,我发现使用像270.1度这样的问题解决了这个问题,但是我想知道为什么270不工作,如果有更好的处理方法.
解决方法
我在iOS 10.1和Safari 10.0.1上经历了这么多的痛苦.该错误绝对是由任意旋转值触发的,该值计算为可整除90度的值.
但是它变得越来越大.
看这个演示/系列的最小测试用例我放在一起(jsfiddle版本here).最好运行该代码段,然后展开到完整页面：
svg {
height: 80px;
width: 80px;
}
circle {
fill: none;
stroke-dasharray: 150;
stroke-width: 4px;
stroke: #6fdb6f;
transform-origin: center center;
}
.degrot {
transform: rotate(-90deg);
}
.degrot-offset {
transform: rotate(-90.1deg);
}
.degrot-offset-more {
transform: rotate(-92deg);
}
.turnrot {
transform: rotate(-0.25turn);
}
.turnrot-offset {
transform: rotate(-0.251turn);
}
svg[viewBox] circle {
stroke-dasharray: 300;
stroke-width: 8px;
}
svg[viewBox].scaledown circle {
stroke-dasharray: 300;
stroke-width: 8px;
}
svg[viewBox].noscale circle {
stroke-dasharray: 150;
stroke-width: 4px;
}
svg[viewBox].scaleup circle {
stroke-dasharray: 75;
stroke-width: 2px;
}
.wc {
will-change: transform;
}
/* Demo prettification */
p:last-child {
margin-bottom: 0;
}
td {
padding: 10px;
}
tr td:first-of-type {
width: 80px;
min-height: 80px;
}
tr + tr td {
border-top: 1px solid #dcdcdc;
}
<table>
<tr><td colspan="2">In Safari 10.0.1 and iOS 10.1,strange behavior can be observed on SVG shapes with <code>rotate</code> values not divisible by 90 degrees,when <code>transform-origin: center center;</code></td></tr>
<tr>
<td>
<svg xmlns="http://www.w3.org/2000/svg">
<circle class="degrot" r="35" cy="40" cx="40" />
</svg>
</td>
<td>
<code>transform: rotate(-90deg);</code>
<p>The stroke improperly begins <a href="https://www.w3.org/TR/SVG11/shapes.html#CircleElement">at 3:00</a>,as if the <code>transform</code> rule hadn't been applied.</p>
</td>
</tr>
<tr>
<td>
<svg xmlns="http://www.w3.org/2000/svg">
<circle class="degrot-offset" r="35" cy="40" cx="40" />
</svg>
</td>
<td>
<code>transform: rotate(-90.1deg);</code>
<p>The stroke begins at (twelve seconds before) 12:00,as expected.</p>
</td>
</tr>
<tr>
<td>
<svg xmlns="http://www.w3.org/2000/svg">
<circle class="turnrot" r="35" cy="40" cx="40" />
</svg>
</td>
<td>
<code>transform: rotate(-0.25turn);</code>
<p>The same bug applies to any <code>rotate</code> value which computes to a multiple of 90 degrees.</p>
</td>
</tr>
<tr>
<td>
<svg xmlns="http://www.w3.org/2000/svg">
<circle class="turnrot-offset" r="35" cy="40" cx="40" />
</svg>
</td>
<td>
<code>transform: rotate(-0.251turn);</code>
<p>43 seconds before noon.</p>
</td>
</tr>
<tr><td colspan="2">But when the SVG element specifies a <code>viewBox</code> which is being scaled down,things can get weird:</td></tr>
<tr>
<td>
<svg viewBox="0 0 160 160" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot" r="70" cy="80" cx="80" />
</svg>
</td>
<td>
<code>transform: rotate(-90deg);</code>
<p>So far,so the same.</p>
</td>
</tr>
<tr>
<td>
<svg viewBox="0 0 160 160" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot-offset" r="70" cy="80" cx="80" />
</svg>
</td>
<td>
<code>transform: rotate(-90.1deg);</code>
<p>But Now,offsetting by a little bit doesn't work,<em>unless</em> you zoom in the page in past a certain zoom threshold (either via pinching,or <code>View > Zoom</code> and/or keyboard shortcut). Try it; it's unsetting!</p>
<p>This is probably because of some rounding of that the zooming engine performs,because...</p>
</td>
</tr>
<tr>
<td>
<svg viewBox="0 0 160 160" class="scaledown" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot-offset-more" r="70" cy="80" cx="80" />
</svg>
</td>
<td>
<code>transform: rotate(-92deg);</code>
<p>offsetting by a larger amount restores expected behavior.</p>
</td>
</tr>
<tr><td colspan="2">If the SVG element is not being scaled <em>down</em>,behavior identical to the first section resumes. Zooming has no effect:</td></tr>
<tr>
<td>
<svg viewBox="0 0 80 80" class="noscale" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot" r="35" cy="40" cx="40" />
</svg>
<svg viewBox="0 0 40 40" class="scaleup" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot" r="17.5" cy="20" cx="20" />
</svg>
</td>
<td>
<code>transform: rotate(-90deg);</code>
<p>
Top: No scaling (viewBox dimensions match parent element's)<br><br>
Bottom: Scaling up (viewBox dimensions half of parent element's)
</p>
</td>
</tr>
<tr>
<td>
<svg viewBox="0 0 80 80" class="noscale" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot-offset" r="35" cy="40" cx="40" />
</svg>
<svg viewBox="0 0 40 40" class="scaleup" xmlns="http://www.w3.org/2000/svg">
<circle class="degrot-offset" r="17.5" cy="20" cx="20" />
</svg>
</td>
<td>
<code>transform: rotate(-90.1deg);</code>
<p>
Top: No scaling (viewBox dimensions match parent element's)<br><br>
Bottom: Scaling up (viewBox dimensions half of parent element's)
</p>
</td>
</tr>
<tr><td colspan="2">But there is one exception:</td></tr>
<tr>
<td>
<svg class="degrot wc" xmlns="http://www.w3.org/2000/svg">
<circle r="35" cy="40" cx="40" />
</svg>
</td>
<td>
<p>On the parent <code>svg</code> element:</p>
<code>transform: rotate(-90deg);<br>will-change: transform;</code>
<p>Iff the the the rotation is applied to a <em>parent</em> of the SVG shape (including the SVG element itself) along with the rule <code>will-change: transform</code>,all rotation values work as expected.</p>
</td>
</tr>
<tr><td colspan="2">All these behaviors have been observed in Safari 10.0.1 and iOS 10.1. They appear to be fixed as of iOS 10.2 Beta 2.</td></tr>
</table>
如演示中所述,它似乎在iOS 10.2中修复,至少在我刚刚下载的公共测试版本中.据推测,Safari修复还将及时到达.
iOS 10.1
iOS 10.2(公开测试版2)