Vector常用语法了解：

M = moveto(M X,Y) ：将画笔移动到指定的坐标位置
L = lineto(L X,Y) ：画直线到指定的坐标位置
H = horizontal lineto(H X)：画水平线到指定的X坐标位置
V = vertical lineto(V Y)：画垂直线到指定的Y坐标位置
C = curveto(C X1,Y1,X2,Y2,ENDX,ENDY)：三次贝赛曲线
S = smooth curveto(S X2,Y2,ENDX,ENDY):平滑曲线
Q = quadratic Belzier curve(Q X,Y,ENDX,ENDY)：二次贝赛曲线
T = smooth quadratic Belzier curveto(T ENDX,ENDY)：映射
A = elliptical Arc(A RX,RY,XROTATION,FLAG1,FLAG2,X,Y)：弧线
A（圆的x轴半径，y轴半径，x轴旋转角度，0/1-小/大弧度，0/1-逆/顺时针，圆的终点位置x点，圆的终点位置y点）
Z = closepath()：关闭路径

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:aapt="http://schemas.android.com/aapt"
    android:width="300dp"
    android:height="300dp"
    android:viewportWidth="99"
    android:viewportHeight="99">

    <path
        android:pathData="M0,0 H99 M0,0 V99 M99,99 H0 M99,99 V0"
        android:strokeWidth="2"
        android:strokeColor="#000000">
        <aapt:attr name="android:fillColor">
            <gradient
                android:angle="0"
                android:centerColor="#B451EC"
                android:endColor="#62A7F0"
                android:endX="99"
                android:endY="99"
                android:startColor="#E364E5"
                android:startX="0"
                android:startY="0"
                android:type="linear" />
        </aapt:attr>
    </path>
</vector>

image.png

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <size
                android:width="100dp"
                android:height="100dp" />
            <gradient
                android:endColor="@android:color/holo_red_light"
                android:startColor="@android:color/holo_blue_light" />
        </shape>
    </item>
    <item
        android:bottom="2dp"
        android:left="2dp"
        android:right="2dp"
        android:top="2dp">
        <shape>
            <solid android:color="@android:color/white" />
        </shape>
    </item>
</layer-list>

image.png