实习杂记（20）---Android里面shape定义图形相关属性

<shape>是根节点，一般设置两个属性

         

xmlns:android

String. Required. Defines the XML namespace, which must be 

"http://schemas.android.com/apk/res/android"

.
这个是必须的，申明Android的命名空间

android:shape

Keyword. Defines the type of shape. Valid values are:（定义这个类型的形状，变量值是：）
这个也是必须的，表示你定义的图形是什么类型，圆，环，直线，长方形

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.

下面是子节点：

第一个子节点：corners

<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。
这个其实说的是：当定义的形状是长方形的时候，长方形左右上下四个边是圆角的，说简单点就是四个角，值越大，角越圆

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.
一般用这个属性 就可以了，下面的四个属性就是详细的去定义了

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.
第二个子节点：gradient

<gradient>

Specifies a gradient color for the shape.指定一个渐变颜色的形状。
这个属性是为了  定义的shape填充颜色的，如果把起始颜色值和结束颜色值设置为一样的，就应该没有渐变了

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.
这个其实是决定渲染方向，是从左到右，从右到左，从上到下，从下到上，

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

.
第三个子节点：padding

<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)
定义的shape 有填充间距，这个应该很好理解，只的是包裹的内容本身与形状的间距，不是形状自身

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.
第四个子节点：size

<size>

The size of the shape.
定义形状的大小，是指形状本身的大小宽和高，这个跟后面的那个stroke节点有点混，stroke是指线条的宽和高，指的是描边

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"

.
第五个子节点：solid

<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.
第六个子节点：stroke

<stroke>

A stroke line for the shape.
这个解释应该就是字面的意思，线条的厚度，

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.