Android 源码VecotorDrawable

 <!-- Drawable used to draw vector paths. -->
    <declare-styleable name="VectorDrawable">
        <!-- If set, specifies the color to apply to the drawable as a tint. By default,
             no tint is applied. May be a color state list. -->
        <attr name="tint" />
        <!-- When a tint color is set, specifies its Porter-Duff blending mode. The
             default value is src_in, which treats the drawable as an alpha mask. -->
        <attr name="tintMode" />
        <!-- Indicates if the drawable needs to be mirrored when its layout direction is
             RTL (right-to-left). -->
        <attr name="autoMirrored" />
        <!-- The intrinsic width of the Vector Drawable. -->
        <attr name="width" />
        <!-- The intrinsic height of the Vector Drawable. -->
        <attr name="height" />
        <!-- The width of the canvas the drawing is on. -->
        <attr name="viewportWidth" format="float"/>
        <!-- The height of the canvas the drawing is on. -->
        <attr name="viewportHeight" format="float"/>
        <!-- The name of this vector drawable -->
        <attr name="name" />
        <!-- The opacity of the whole vector drawable, as a value between 0
             (completely transparent) and 1 (completely opaque). -->
        <attr name="alpha" />
    </declare-styleable>