There are several ways to color shapes (including specifying attributes on the object) using inline CSS , an embedded CSS section, or an external CSS file. Most SVG you'll find around the web use inline CSS, but there are advantages and disadvantages associated with each type.
Basic coloring can be done by setting two attributes on the node:
fill
and
stroke
。使用
fill
sets the color inside the object and
stroke
sets the color of the line drawn around the object. You can use the same css color naming schemes that you use in HTML, whether that's color names (that is
red
), rgb values (that is
rgb(255,0,0)
), hex values, rgba values, etc.
<rect x="10" y="10" width="100" height="100" stroke="blue" fill="purple"
fill-opacity="0.5" stroke-opacity="0.8"/>
In addition, you can specify the opacity of either the
fill
or
stroke
separately in SVG. These are controlled by the
fill-opacity
and
stroke-opacity
属性。
注意：
In Firefox,
rgba
values are also allowed, and will give the same effect. But for compatibility with other viewers, it's often best to specify the
fill
/
stroke
opacity separately. If you specify both an
rgba
value and a
fill
/
stroke
opacity value, both will be applied.
In addition to its color properties, there are a few other attributes available to control the way a stroke is drawn on a line.
<?xml version="1.0" standalone="no"?>
<svg width="160" height="140" xmlns="http://www.w3.org/2000/svg" version="1.1">
<line x1="40" x2="120" y1="20" y2="20" stroke="black" stroke-width="20" stroke-linecap="butt"/>
<line x1="40" x2="120" y1="60" y2="60" stroke="black" stroke-width="20" stroke-linecap="square"/>
<line x1="40" x2="120" y1="100" y2="100" stroke="black" stroke-width="20" stroke-linecap="round"/>
</svg>
stroke-width
property defines the width of this stroke. Strokes are drawn centered around the path. In the example above, the path is shown in pink, and the stroke in black.
The second attribute affecting strokes is the
stroke-linecap
property, demonstrated above. This controls the shape of the ends of lines.
There are three possible values for
stroke-linecap
:
butt
closes the line off with a straight edge that's normal (at 90 degrees) to the direction of the stroke and crosses its end.
square
has essentially the same appearance, but stretches the stroke slightly beyond the actual path. The distance that the stroke goes beyond the path is half the
stroke-width
.
round
produces a rounded effect on the end of the stroke. The radius of this curve is also controlled by the
stroke-width
.
使用
stroke-linejoin
to control how the joint between two line segments is drawn.
<?xml version="1.0" standalone="no"?>
<svg width="160" height="280" xmlns="http://www.w3.org/2000/svg" version="1.1">
<polyline points="40 60 80 20 120 60" stroke="black" stroke-width="20"
stroke-linecap="butt" fill="none" stroke-linejoin="miter"/>
<polyline points="40 140 80 100 120 140" stroke="black" stroke-width="20"
stroke-linecap="round" fill="none" stroke-linejoin="round"/>
<polyline points="40 220 80 180 120 220" stroke="black" stroke-width="20"
stroke-linecap="square" fill="none" stroke-linejoin="bevel"/>
</svg>
Each of these polylines has two segments. The joint where the two meet is controlled by the
stroke-linejoin
attribute. There are three possible values for this attribute.
miter
extends the line slightly beyond its normal width to create a square corner where only one angle is used.
round
creates a rounded line segment.
bevel
creates a new angle to aid in the transition between the two segments.
Finally, you can also use dashed line types on a stroke by specifying the
stroke-dasharray
属性。
<?xml version="1.0" standalone="no"?>
<svg width="200" height="150" xmlns="http://www.w3.org/2000/svg" version="1.1">
<path d="M 10 75 Q 50 10 100 75 T 190 75" stroke="black"
stroke-linecap="round" stroke-dasharray="5,10,5" fill="none"/>
<path d="M 10 75 L 190 75" stroke="red"
stroke-linecap="round" stroke-width="1" stroke-dasharray="5,5" fill="none"/>
</svg>
stroke-dasharray
attribute takes a series of comma-separated numbers as its argument.
注意：
不像
<path>
elements, these numbers
must
be comma-separated (whitespace is ignored).
The first number specifies a distance for the filled area, and the second a distance for the unfilled area. So in the above example, the second path fills 5 pixel units, with 5 blank units until the next dash of 5 units. You can specify more numbers if you would like a more complicated dash pattern. The first example specifies three numbers, in which case the renderer loops the numbers twice to create an even pattern. So the first path renders 5 filled, 10 empty, 5 filled, and then loops back to create 5 empty, 10 filled, 5 empty. The pattern then repeats.
There are additional
stroke
and
fill
properties available, including
fill-rule,
which specifies how to color in shapes that overlap themselves;
stroke-miterlimit
, which determines if a stroke should draw miters; and
stroke-dashoffset
, which specifies where to start a dasharray on a line.
In addition to setting attributes on objects, you can also use CSS to style fills and strokes. Not all attributes can be set via CSS. Attributes that deal with painting and filling are usually available, so
fill
,
stroke
,
stroke-dasharray
, etc... can all be set this way, in addition to the gradient and pattern versions of those shown below. Attributes like
width
,
height
，或
<path>
commands cannot be set through CSS. It's easiest just to test and find out what is available and what isn't.
注意： SVG specification decides strictly between attributes that are properties and other attributes. The former can be modified with CSS, the latter not.
CSS can be inserted inline with the element via the
style
属性：
<rect x="10" height="180" y="10" width="180" style="stroke: black; fill: red;"/>
Or it can be moved to a special style section that you include. Instead of shoving such a section into a
<head>
section like you do in HTML, though, it's included in an area called
<defs>
.
<defs>
stands for definitions, and it is here that you can create elements that don't appear in the SVG directly, but are used by other elements.
<?xml version="1.0" standalone="no"?>
<svg width="200" height="200" xmlns="http://www.w3.org/2000/svg" version="1.1">
<defs>
<style type="text/css"><![CDATA[
#MyRect {
stroke: black;
fill: red;
}
]]></style>
</defs>
<rect x="10" height="180" y="10" width="180" id="MyRect"/>
</svg>
Moving styles to an area like this can make it easier to adjust properties on large groups of elements. You can also use things like the
:hover
pseudo class
to create rollover effects:
#MyRect:hover {
stroke: black;
fill: blue;
}
You can also specify an external stylesheet for your CSS rules through normal XML-stylesheet syntax :
<?xml version="1.0" standalone="no"?>
<?xml-stylesheet type="text/css" href="style.css"?>
<svg width="200" height="150" xmlns="http://www.w3.org/2000/svg" version="1.1">
<rect height="10" width="10" id="MyRect"/>
</svg>
Where
style.css
looks something like:
#MyRect {
fill: red;
stroke: black;
}
最后修改： , 由 MDN 贡献者