android:shape属性详解

这一类的shape定义在xml中

元素:

<shape>

The shape drawable. This must be the root element.

attributes:

xmlns:android

String. Required. Defines the XML namespace, which must be "http://schemas.android.com/apk/res/android".

android:shape

Keyword. Defines the type of shape. Valid values are:（定义这个类型的形状，变量值是：）

Value	Desciption
"rectangle"	A rectangle （长方形）that fills the containing View. This is the default shape.（这个是默认的形状）
"oval"	An oval （椭圆形）shape that fits the dimensions of the containing View.
"line"	A horizontalline that spans the width of the containing View. This shape requires the <stroke> element to define the width of the line.
"ring"	A ring shape.

The following attributes are used only when android:shape="ring":

android:innerRadius

Dimension. The radius for the inner part of the ring (the hole in the middle), as a dimension value or dimension resource.

android:innerRadiusRatio

Float. The radius for the inner part of the ring, expressed as a ratio of the ring's width. For instance, if android:innerRadiusRatio="5", then the inner radius equals the ring's width divided by 5. This value is overridden by android:innerRadius. Default value is 9.

android:thickness

Dimension. The thickness of the ring, as a dimension value or dimension resource.

android:thicknessRatio

Float. The thickness of the ring, expressed as a ratio of the ring's width. For instance, if android:thicknessRatio="2", then the thickness equals the ring's width divided by 2. This value is overridden by android:innerRadius. Default value is 3.

android:useLevel

Boolean. "true" if this is used as a LevelListDrawable. This should normally be "false" or your shape may not appear.

<corners>

Creates rounded corners for the shape. Applies only when the shape is a rectangle.创建圆角的形状。仅适用于当其形状是一个长方形。

attributes:

android:radius

Dimension. The radius for all corners, as a dimension value or dimension resource. This is overridden for each corner by the following attributes.

android:topLeftRadius

Dimension. The radius for the top-left corner, as a dimension value or dimension resource.

android:topRightRadius

Dimension. The radius for the top-right corner, as a dimension value or dimension resource.

android:bottomLeftRadius

Dimension. The radius for the bottom-left corner, as a dimension value or dimension resource.

android:bottomRightRadius

Dimension. The radius for the bottom-right corner, as a dimension value or dimension resource.

Note: Every corner must (initially) be provided a corner radius greater than 1, or else no corners are rounded. If you want specific corners to notbe rounded, a work-around is to use android:radius to set a default corner radius greater than 1, but then override each and every corner with the values you really want, providing zero ("0dp") where you don't want rounded corners.

<gradient>

Specifies a gradient color for the shape.指定一个渐变颜色的形状。

attributes:

android:angle

Integer. The angle for the gradient, in degrees. 0 is left to right, 90 is bottom to top. It must be a multiple of 45. Default is 0.

android:centerX

Float. The relative X-position for the center of the gradient (0 - 1.0).

android:centerY

Float. The relative Y-position for the center of the gradient (0 - 1.0).

android:centerColor

Color. Optional color that comes between the start and end colors, as a hexadecimal value or color resource.

android:endColor

Color. The ending color, as a hexadecimal value or color resource.

android:gradientRadius

Float. The radius for the gradient. Only applied when android:type="radial".

android:startColor

Color. The starting color, as a hexadecimal value or color resource.

android:type

Keyword. The type of gradient pattern to apply. Valid values are:

Value	Description
"linear"	A linear gradient. This is the default.
"radial"	A radial gradient. The start color is the center color.
"sweep"	A sweeping line gradient.

android:useLevel

Boolean. "true" if this is used as a LevelListDrawable.

<padding>

Padding to apply to the containing View element (this pads the position of the View content, not the shape).适用于包含填充视图元素(这垫的位置,而不是观点内容的形状)

attributes:

android:left

Dimension. Left padding, as a dimension value or dimension resource.

android:top

Dimension. Top padding, as a dimension value or dimension resource.

android:right

Dimension. Right padding, as a dimension value or dimension resource.

android:bottom

Dimension. Bottom padding, as a dimension value or dimension resource.

<size>

The size of the shape.

attributes:

android:height

Dimension. The height of the shape, as a dimension value or dimension resource.

android:width

Dimension. The width of the shape, as a dimension value or dimension resource.

Note: The shape scales to the size of the container View proportionate to the dimensions defined here, by default. When you use the shape in an ImageView, you can restrict scaling by setting the android:scaleType to "center".

<solid>

A solid color to fill the shape.

attributes:

android:color

Color. The color to apply to the shape, as a hexadecimal value or color resource.

<stroke>

A stroke line for the shape.

attributes:

android:width

Dimension. The thickness of the line, as a dimension value or dimension resource.

android:color

Color. The color of the line, as a hexadecimal value or color resource.

android:dashGap

Dimension. The distance between line dashes, as a dimension value or dimension resource. Only valid if android:dashWidth is set.

android:dashWidth

Dimension. The size of each dash line, as a dimension value or dimension resource. Only valid if android:dashGap is set.

gradient   -- 对应颜色渐变。 startcolor、endcolor就不多说了。 android:angle 是指从哪个角度开始变。

android:startColor和android:endColor分别为起始和结束颜色，android:angle是渐变角度，必须为45的整数倍。
另外渐变默认的模式为android:type="linear"，即线性渐变，可以指定渐变为径向渐变，android:type="radial"，径向渐变需要指定半径android:gradientRadius="50"。

solid      --  填充。

android:color指定填充的颜色

stroke   --  描边。

android:width="2dp" 描边的宽度，android:color 描边的颜色。
我们还可以把描边弄成虚线的形式，设置方式为：
android:dashWidth="5dp" 
android:dashGap="3dp"