SVG ----scalable vector Graphics
可缩放矢量图形
android L 即android 5.0的新特性。
1,SVG是干什么的?
可缩放矢量图形是基于可扩展标记语言(标准通用标记语言的子集),用于描述二维矢量图形的一种图形格式。它由万维网联盟制定,是一个开放标准。
2,SVG特点?
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SVG 可被非常多的工具读取和修改(比如记事本)
-
SVG 与 JPEG 和 GIF 图像比起来,尺寸更小,且可压缩性更强。
-
SVG 是可伸缩的
-
SVG 图像可在任何的分辨率下被高质量地打印
-
SVG 可在图像质量不下降的情况下被放大
-
SVG 图像中的文本是可选的,同时也是可搜索的(很适合制作地图)
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SVG 可以与 Java 技术一起运行
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SVG 是开放的标准
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SVG 文件是纯粹的 XML
官网的例子:
<!-- res/drawable/heart.xml -->
<vector xmlns:android="http://schemas.android.com/apk/res/android"
<!-- intrinsic size of the drawable -->
android:height="256dp"
android:width="256dp"
<!-- size of the virtual canvas -->
android:viewportWidth="32"
android:viewportHeight="32">
<!-- draw a path -->
<path android:fillColor="#8fff"
android:pathData="M20.5,9.5
c-1.955,0,-3.83,1.268,-4.5,3
c-0.67,-1.732,-2.547,-3,-4.5,-3
C8.957,9.5,7,11.432,7,14
c0,3.53,3.793,6.257,9,11.5
c5.207,-5.242,9,-7.97,9,-11.5
C25,11.432,23.043,9.5,20.5,9.5z" />
</vector>
这样就定义好了一个静态的矢量图,可以像一般的图片资源使用,设置到imageView中会显示出一个心形。控制显示心形的就是上面path
这个标签,一个path
代表一个元素,绘制的内容是pathData
下的一长串字符,里面是SVG绘制的一系列命令,提供moveTo、lineTo、close等操作,可以和Graphics 中的Path操作对应起来。
在android中使用矢量图有一下步骤:
1,在drawable资源下面创建矢量图的.xml文件
vector.xml
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:height="256dp"
android:width="256dp"
android:viewportHeight="32"
android:viewportWidth="32" >
<path
android:fillColor="#0000FF"
android:pathData="
M20.5,9.5
c-1.955,0,-3.83,1.268,-4.5,3
c-0.67,-1.732,-2.547,-3,-4.5,-3
C8.957,9.5,7,11.432,7,14
c0,3.53,3.793,6.257,9,11.5
C25,11.432,23.043,9.5,20.5,9.5z
" />
</group>
</vector>
其中
android:height="256dp" -- SVG图形的高度
android:width="256dp"-- SVG图形的宽度
android:viewportHeight="32" -- SVG图形划分的比例
android:viewportWidth="32" -- SVG图形划分的比例
宽高划分为32等分,必须保持android:height和android:viewportHeight,android:width,android:viewportWidth比例一致。
M 100 100 L 300,200 L 200,300 Z
- M moveto(M X,Y):画笔移动到指定坐标,未绘制 move to 移动绘制点 ,就是从坐标100,100向300,200坐标移动,画条直线,300,200-->200,300画条直线。
- L:lineto(L X,Y) 绘制直线到,x,y坐标
- Z:close 闭合--也就是svg的结束位置
- C:cubic bezier 三次贝塞尔曲线
- Q:quatratic bezier curve (Q X,Y,ENDX,ENDY)二次贝塞尔曲线
- A:ellipse 圆弧
- H:horizontal line to 水平直线
- T : smooth quadratic curve (Q X,Y,ENDX,ENDY):映射前面路径后的终点。
在布局文件中使用:
<ImageVIew
android:id="@+id/imageVIew1"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:layout_alignParentTop="true"
android:layout_centerhorizontal = "true"
android:src = "@drawable/vector"
/>
效果图:
然后分享两个svg值获取的方法:
http://svg-edit.googlecode.com/svn/branches/2.4/editor/svg-editor.html
一个是个离线的工具:
inkscape
界面:
然后将svg保存到桌面上,并用浏览器打开:
查看svg信息:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!-- Created with Inkscape (http://www.inkscape.org/) -->
<svg
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:cc="http://creativecommons.org/ns#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:svg="http://www.w3.org/2000/svg"
xmlns="http://www.w3.org/2000/svg"
xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
width="744.09448819"
height="1052.3622047"
id="svg2"
version="1.1"
inkscape:version="0.48.4 r9939"
sodipodi:docname="新建文档 1">
<defs
id="defs4" />
<sodipodi:namedview
id="base"
pagecolor="#ffffff"
bordercolor="#666666"
borderopacity="1.0"
inkscape:pageopacity="0.0"
inkscape:pageshadow="2"
inkscape:zoom="0.35"
inkscape:cx="375"
inkscape:cy="405.71429"
inkscape:document-units="px"
inkscape:current-layer="layer1"
showgrid="false"
inkscape:window-width="1280"
inkscape:window-height="738"
inkscape:window-x="-8"
inkscape:window-y="-8"
inkscape:window-maximized="1" />
<metadata
id="metadata7">
<rdf:RDF>
<cc:Work
rdf:about="">
<dc:format>image/svg+xml</dc:format>
<dc:type
rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
<dc:title></dc:title>
</cc:Work>
</rdf:RDF>
</metadata>
<g
inkscape:label="Layer 1"
inkscape:groupmode="layer"
id="layer1">
<path
sodipodi:type="arc"
style="fill:#ff0000;fill-rule:evenodd;stroke:#000000;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
id="path2985"
sodipodi:cx="402.85715"
sodipodi:cy="385.21933"
sodipodi:rx="217.14285"
sodipodi:ry="230"
d="m 620,385.21933 a 217.14285,230 0 1 1 -434.28571,0 217.14285,230 0 1 1 434.28571,0 z" />
<path
sodipodi:type="star"
style="fill:#ffff00;fill-rule:evenodd;stroke:#000000;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
id="path2987"
sodipodi:sides="5"
sodipodi:cx="205.71429"
sodipodi:cy="349.50504"
sodipodi:r1="149.99319"
sodipodi:r2="74.996597"
sodipodi:arg1="1.2610934"
sodipodi:arg2="1.8894119"
inkscape:flatsided="false"
inkscape:rounded="0"
inkscape:randomized="0"
d="m 251.42858,492.36218 -69.20713,-71.63513 -98.24588,16.40014 46.74287,-87.95636 -45.957098,-88.36947 98.095808,17.27511 69.84283,-71.01547 13.88368,98.63296 89.12234,44.47949 -89.51523,43.68342 z"
inkscape:transform-center-x="-14.126491"
inkscape:transform-center-y="0.20655178"
transform="translate(214.28571,37.142857)" />
</g>
</svg>
AnimateVectorDrawable
为矢量图片添加动画效果
MainActivity.java
public class MainActivity extends AppCompatActivity { @SuppressLint("NewApi") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final ImageView robot = (ImageView) findViewById(R.id.main_vector_robot); Drawable avd = ResourcesCompat.getDrawable(this, R.drawable.ic_robot_avd); robot.setBackground(avd); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) {
//动画的执行 ((Animatable) robot.getBackground()).start(); } }); } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <ImageView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/main_vector_robot" android:layout_width="250dp" android:layout_height="290dp" android:layout_gravity="center" /> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:layout_margin="@dimen/fab_margin" android:src="@android:drawable/ic_media_play" /> </FrameLayout>
Drawable avd = ResourcesCompat.getDrawable(this, R.drawable.ic_robot_avd);
robot.setBackground(avd);为ImageView添加svg背景动画
svg对应的xml:
<?xml version="1.0" encoding="UTF-8"?> <vector xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:width="24dp" android:height="24dp" android:viewportHeight="404.0" android:viewportWidth="344.0" app:vc_viewportHeight="404.0" app:vc_viewportWidth="344.0" tools:ignore="NewApi" > <path android:fillColor="#9FBF3B" android:pathData="M223.86627,35.298L243.98503,6.026C245.17964,4.286 244.88223,2.002 243.32036,0.922C241.76048,-0.152 239.52295,0.379 238.33733,2.121L217.42815,32.53C203.6487,27.091 188.3473,24.06 172.21956,24.06C156.09181,24.06 140.78642,27.088 127.00798,32.53L106.1018,2.12C104.90319,0.38 102.66966,-0.153 101.10878,0.921C99.547905,1.998 99.251495,4.283 100.446106,6.025L120.57185,35.297C88.57285,50.213 66.13274,78.557 63.273453,111.637L281.1537,111.637C278.30438,78.557 255.86327,50.214 223.86627,35.298" android:strokeColor="#00000000" android:strokeWidth="1" app:vc_fillColor="#9FBF3B" app:vc_pathData="M223.86627,35.298L243.98503,6.026C245.17964,4.286 244.88223,2.002 243.32036,0.922C241.76048,-0.152 239.52295,0.379 238.33733,2.121L217.42815,32.53C203.6487,27.091 188.3473,24.06 172.21956,24.06C156.09181,24.06 140.78642,27.088 127.00798,32.53L106.1018,2.12C104.90319,0.38 102.66966,-0.153 101.10878,0.921C99.547905,1.998 99.251495,4.283 100.446106,6.025L120.57185,35.297C88.57285,50.213 66.13274,78.557 63.273453,111.637L281.1537,111.637C278.30438,78.557 255.86327,50.214 223.86627,35.298"/> <path android:fillColor="#FFFFFF" android:pathData="M126.7026,81.438C120.042915,81.438 114.646706,76.031 114.646706,69.359C114.646706,62.688 120.03992,57.279 126.7026,57.279C133.35728,57.279 138.7515,62.686 138.7515,69.359C138.7525,76.03 133.35728,81.438 126.7026,81.438" android:strokeColor="#00000000" android:strokeWidth="1" app:vc_fillColor="#FFFFFF" app:vc_pathData="M126.7026,81.438C120.042915,81.438 114.646706,76.031 114.646706,69.359C114.646706,62.688 120.03992,57.279 126.7026,57.279C133.35728,57.279 138.7515,62.686 138.7515,69.359C138.7525,76.03 133.35728,81.438 126.7026,81.438"/> <path android:fillColor="#FFFFFF" android:pathData="M217.72556,81.438C211.07086,81.438 205.67564,76.031 205.67564,69.359C205.67564,62.686 211.07086,57.279 217.72556,57.279C224.38722,57.279 229.78044,62.688 229.78044,69.359C229.78044,76.03 224.38522,81.438 217.72556,81.438" android:strokeColor="#00000000" android:strokeWidth="1" app:vc_fillColor="#FFFFFF" app:vc_pathData="M217.72556,81.438C211.07086,81.438 205.67564,76.031 205.67564,69.359C205.67564,62.686 211.07086,57.279 217.72556,57.279C224.38722,57.279 229.78044,62.688 229.78044,69.359C229.78044,76.03 224.38522,81.438 217.72556,81.438"/> <path android:name="robot_left_hand" android:fillColor="#9FBF3B" android:pathData="M49.28443,249.598C49.28443,263.048 38.402195,273.952 24.978045,273.952L24.978045,273.952C11.554891,273.952 0.6726547,263.048 0.6726547,249.598L0.6726547,151.09C0.6726547,137.64 11.554891,126.736 24.978045,126.736L24.978045,126.736C38.402195,126.736 49.28443,137.64 49.28443,151.09L49.28443,249.598L49.28443,249.598Z" android:strokeColor="#00000000" android:strokeWidth="1" app:vc_fillColor="#9FBF3B" app:vc_pathData="M49.28443,249.598C49.28443,263.048 38.402195,273.952 24.978045,273.952L24.978045,273.952C11.554891,273.952 0.6726547,263.048 0.6726547,249.598L0.6726547,151.09C0.6726547,137.64 11.554891,126.736 24.978045,126.736L24.978045,126.736C38.402195,126.736 49.28443,137.64 49.28443,151.09L49.28443,249.598L49.28443,249.598Z"/> <path android:name="robot_body" android:fillColor="#9FBF3B" android:pathData="M63.269463,127.489L63.269463,305.404C63.269463,315.97 71.81837,324.537 82.366264,324.537L104.954094,324.537L104.954094,379.281C104.954094,392.732 115.83533,403.635 129.25948,403.635C142.68364,403.635 153.56587,392.732 153.56587,379.281L153.56587,324.537L190.86227,324.537L190.86227,379.281C190.86227,392.732 201.74251,403.635 215.16766,403.635C228.59282,403.635 239.47305,392.732 239.47305,379.281L239.47305,324.537L262.06088,324.537C272.6088,324.537 281.15967,315.975 281.15967,305.404L281.15967,127.489L63.269463,127.489L63.269463,127.489Z" android:strokeColor="#00000000" android:strokeWidth="1" app:vc_fillColor="#9FBF3B" app:vc_pathData="M63.269463,127.489L63.269463,305.404C63.269463,315.97 71.81837,324.537 82.366264,324.537L104.954094,324.537L104.954094,379.281C104.954094,392.732 115.83533,403.635 129.25948,403.635C142.68364,403.635 153.56587,392.732 153.56587,379.281L153.56587,324.537L190.86227,324.537L190.86227,379.281C190.86227,392.732 201.74251,403.635 215.16766,403.635C228.59282,403.635 239.47305,392.732 239.47305,379.281L239.47305,324.537L262.06088,324.537C272.6088,324.537 281.15967,315.975 281.15967,305.404L281.15967,127.489L63.269463,127.489L63.269463,127.489Z"/> <path android:name="robot_right_hand" android:fillColor="#9FBF3B" android:pathData="M295.1437,249.598C295.1437,263.048 306.02496,273.952 319.4491,273.952L319.4491,273.952C332.87225,273.952 343.7545,263.048 343.7545,249.598L343.7545,151.09C343.7545,137.64 332.87225,126.736 319.4491,126.736L319.4491,126.736C306.02496,126.736 295.1437,137.64 295.1437,151.09L295.1437,249.598L295.1437,249.598Z" android:strokeColor="#00000000" android:strokeWidth="1" app:vc_fillColor="#9FBF3B" app:vc_pathData="M295.1437,249.598C295.1437,263.048 306.02496,273.952 319.4491,273.952L319.4491,273.952C332.87225,273.952 343.7545,263.048 343.7545,249.598L343.7545,151.09C343.7545,137.64 332.87225,126.736 319.4491,126.736L319.4491,126.736C306.02496,126.736 295.1437,137.64 295.1437,151.09L295.1437,249.598L295.1437,249.598Z"/> </vector>
对应的动画:
<?xml version="1.0" encoding="utf-8"?> <animated-vector xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:drawable="@drawable/ic_robot" tools:ignore="NewApi"> <target android:name="robot_body" android:animation="@anim/robot_body" /> <target android:name="robot_left_hand" android:animation="@anim/robot_left_hand" /> </animated-vector>
指向两个动画文件:robot_body.xml和robot_left_hand.xml
robot_body.xml是个属性动画xml文件:
<?xml version="1.0" encoding="utf-8"?> <objectAnimator xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:duration="@android:integer/config_longAnimTime" android:interpolator="@android:interpolator/fast_out_slow_in" android:repeatCount="1" android:repeatMode="reverse" android:propertyName="pathData" android:valueFrom="@string/body_path_from" android:valueTo="@string/body_path_to" android:valueType="pathType" app:vc_valueType="pathType" />
robot_left_hand.xml也是个属性动画xml文件:
<?xml version="1.0" encoding="utf-8"?> <objectAnimator xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:duration="@android:integer/config_longAnimTime" android:interpolator="@android:interpolator/fast_out_slow_in" android:propertyName="pathData" android:repeatCount="1" android:repeatMode="reverse" android:valueFrom="@string/left_hand_path_from" android:valueTo="@string/left_hand_path_to" android:valueType="pathType" app:vc_valueType="pathType" />
红色部分就是svg值,因此如果你在android svg开发中如果为svg值头疼可以参考这个工具来写。
关于兼容性:
众所周知svg概念在android上是出现在android 5.0以后的,所以也出现了相关的兼容性的问题:
1 ,首先style的兼容性:
res/values/styles.xml android低版本默认读取
res/values_v21/styles.xml 这个尽可能使用android5.0风格的特性
2 ,layout布局文件,重点是一些控件的支持:
res/layout/activity.xml 所有通用的布局在这里写。
res/layout_v21/activity.xml 使用android 5.0新特性的一些控件的布局。
3 ,support library 比如recycleview cardview等的向下兼容:
4,就是通过检测系统的版本来调用不同系统版本的api
if(Build.VERSION.SDK-INT>=build.VERSION_CODES.LOLIPOP){
//使用材料设计的5.0新特性
}else{
//使用低于5.0的通用各版本方法
}