Android：释放自己的双手，无需手动创建shape文件

大家好，我是似曾相识2022。I don't like a crime，but to sleep's Rap lonely.

现在的移动应用中为了美化界面，会给各类视图增加一些圆角、描边、渐变等等效果。当然系统也提供了对应的功能，那就是创建形状标签的XMLThe results showed that the results of the study showed that the results of the results形状文件。再把这个文件设置给目标视图作为背景，就达到了我们想要的圆角效果。

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <corners android:radius="8dp" />
    <solid android:color="#FFFFFF" />
</shape>

//圆角效果
android:background="@drawable/shape_white_r10"

但不是所有的圆角和颜色都一样，甚至还有四个角单独一个有圆角的情况，当然还有描边、虚线描边、渐变填充色等等各类情况。随着曲面效果的多样性和复杂性，我们添加的形状文件也成倍增加。

这时候不少的技术都出现了，大家都明显神通地制造了许多自定义视图。这样我们就可以使用三方库通过在目标视图外嵌套一层视图来达到原本的圆角等效果。不能不说，这确实能够大大减少我们手动创建各类形状的情况，使用起来也是手到擒来，方便了不少。

问题：

简单的布局，嵌套层级较少的页面使用起来还好。但往往随着页面的复杂程度越高，嵌套层级也越来多，这个时候再使用三方库外层嵌套视图会越来越臃肿和复杂。那么有没有一种方式可以直接在XML中当前视图中增减圆角等效果呢？

还真有，使用数据绑定Can get to！

这里就不单独介绍数据绑定的基础配置，网上一搜到处都是。调用者直接进入正问题，使用**@BindingAdapter** 注释，这是用来扩展布局的XML属性行为的注解。

使用数据绑定实现圆角

//自定义shape_radius、shape_solidColor字段  即圆角和填充颜色
@BindingAdapter(value = ["shape_radius"，"shape_solidColor"])
fun View.setViewBackground(radius: Int = 0,solidColor: Int = Color.TRANSPARENT){
    val drawable = GradientDrawable()
    drawable.cornerRadius = context.dp2px(radius.toFloat()).toFloat()
    drawable.setColor(solidColor)
    background = drawable
}

//xml文件中
shape_radius="@{10}"
shape_solidColor="@{@color/white}"

其实就是对当前视图的一个扩展，有点和Kotlin的扩展函数类似。既然这样我们可以通过代码配置更多自定义的属性：

各方向圆角的实现：

//自定义shape_radius、shape_solidColor字段  即圆角和填充颜色
@BindingAdapter(value = ["
"shape_solidColor",//填充颜色
"shape_tl_radius",//上左圆角
"shape_tr_radius",//上右圆角
"shape_bl_radius",//下左圆角
"shape_br_radius"//下右圆角
])
fun View.setViewBackground(radius: Int = 0,solidColor: Int = Color.TRANSPARENT){
    val drawable = GradientDrawable()
    drawable.setColor(solidColor)
    drawable.cornerRadii = floatArrayOf(
            context.dp2px(shape_tl_radius.toFloat()).toFloat(),
            context.dp2px(shape_tl_radius.toFloat()).toFloat(),
            context.dp2px(shape_tr_radius.toFloat()).toFloat(),
            context.dp2px(shape_tr_radius.toFloat()).toFloat(),
            context.dp2px(shape_br_radius.toFloat()).toFloat(),
            context.dp2px(shape_br_radius.toFloat()).toFloat(),
            context.dp2px(shape_bl_radius.toFloat()).toFloat(),
            context.dp2px(shape_bl_radius.toFloat()).toFloat(),
        )
    background = drawable
}

//xml文件中
shape_radius="@{10}"
shape_tl_radius="@{@color/white}"//左上角
shape_tr_radius="@{@color/white}"//右上角
shape_bl_radius="@{@color/white}"//左下角
shape_br_radius="@{@color/white}"//右下角

虚线描边：

//自定义shape_radius、shape_solidColor字段  即圆角和填充颜色
@BindingAdapter(value = [
"shape_radius"，
"shape_solidColor"，
"shape_strokeWitdh",//描边宽度
"shape_dashWith",//描边虚线单个宽度
"shape_dashGap",//描边间隔宽度
])
fun View.setViewBackground(
radius: Int = 0,
solidColor: Int = Color.TRANSPARENT，
strokeWidth: Int = 0,
shape_dashWith: Int = 0,
shape_dashGap: Int = 0
){
    val drawable = GradientDrawable()
    drawable.setStroke(
        context.dp2px(strokeWidth.toFloat()),
        strokeColor,
        shape_dashWith.toFloat(),
        shape_dashGap.toFloat()
    )
    drawable.setColor(solidColor)
    background = drawable
}

//xml文件中
shape_radius="@{10}"
shape_solidColor="@{@color/white}"
strokeWidth="@{1}"
shape_dashWith="@{2}"
shape_dashGap="@{3}"

渐变色的使用：

//自定义shape_radius、shape_solidColor字段  即圆角和填充颜色
@BindingAdapter(value = [
"shape_startColor",//渐变开始颜色
"shape_centerColor",//渐变中间颜色
"shape_endColor",//渐变结束颜色
"shape_gradualOrientation",//渐变角度
])
fun View.setViewBackground(
shape_startColor: Int = Color.TRANSPARENT,
shape_centerColor: Int = Color.TRANSPARENT,
shape_endColor: Int = Color.TRANSPARENT,
shape_gradualOrientation: Int = 1,//TOP_BOTTOM = 1 ,TR_BL = 2,RIGHT_LEFT = 3,BR_TL = 4,BOTTOM_TOP = 5,BL_TR = 6,LEFT_RIGHT = 7,TL_BR = 8
){
val drawable = GradientDrawable()
when (shape_gradualOrientation) {
    1 -> drawable.orientation = GradientDrawable.Orientation.TOP_BOTTOM
    2 -> drawable.orientation = GradientDrawable.Orientation.TR_BL
    3 -> drawable.orientation = GradientDrawable.Orientation.RIGHT_LEFT
    4 -> drawable.orientation = GradientDrawable.Orientation.BR_TL
    5 -> drawable.orientation = GradientDrawable.Orientation.BOTTOM_TOP
    6 -> drawable.orientation = GradientDrawable.Orientation.BL_TR
    7 -> drawable.orientation = GradientDrawable.Orientation.LEFT_RIGHT
    8 -> drawable.orientation = GradientDrawable.Orientation.TL_BR
}
drawable.gradientType = GradientDrawable.LINEAR_GRADIENT//线性
drawable.shape = GradientDrawable.RECTANGLE//矩形方正
drawable.colors = if (shape_centerColor != Color.TRANSPARENT) {//有中间色
    intArrayOf(
        shape_startColor,
        shape_centerColor,
        shape_endColor
    )
} else {
    intArrayOf(shape_startColor, shape_endColor)
}//渐变色
background = drawable
}

//xml文件中
shape_startColor="@{@color/cl_F1E6A0}"
shape_centerColor="@{@color/cl_F8F8F8}"
shape_endColor=@{@color/cl_3CB9FF}

不止设置形状功能，只要可以通过代码设置的功能一样可以在绑定适配器注解中自定义，使用起来是不是更加方便了。

总结：

• 注解绑定适配器中值数组的自定义属性一样要和方法内的参数一一对应，否则报错。
• The results showed that the increase of the expression of the protein was significantly lower in the patients with acute myeloid leukemia.
• In this paper，we study the relationship between the mechanism and the relationship between the mechanism and the relationship between the mechanism and the relationship between the mechanism and the relationship between the mechanism.

In this paper，we discuss the relationship between the mechanism and the relationship between mechanism.

标签：自己的双手文件安卓系统形状