写了一个这个Banner的工具类，用kotlin实现了一个画廊效果

import android.annotation.SuppressLint

import android.view.View

import android.widget.RelativeLayout

import com.youth.banner.Banner

import com.youth.banner.transformer.ABaseTransformer

import com.youth.banner.view.BannerViewPager

import kotlin.math.absoluteValue

/**

* @author jijunpeng created on 2018/2/28.

*/

object BannerUtil {

@SuppressLint("ClickableViewAccessibility")

fun galleryStyle(banner: Banner, bannerWidthScale: Float = 0.7F, bannerItemScale: Float = 0.8F, bannerItemSpaceScale: Float = 0.1F) {

val bannerViewPager = banner.findViewById(com.youth.banner.R.id.bannerViewPager)

bannerViewPager.setPageTransformer(false, ScaleInOutTransformer(bannerItemScale, bannerItemSpaceScale))

banner.setOffscreenPageLimit(5)

var bannerWidth = 0

with(bannerViewPager.layoutParams) {

this.width = if (this.width <= 0) {

(banner.context.resources.displayMetrics.widthPixels * bannerWidthScale).toInt()

} else {

(this.width * bannerWidthScale).toInt()

}

this as RelativeLayout.LayoutParams

this.addRule(android.widget.RelativeLayout.CENTER_IN_PARENT)

bannerWidth = this.width

}

bannerViewPager.pageMargin = (-bannerItemSpaceScale * bannerWidth).toInt()

banner.setOnTouchListener { v, event ->

bannerViewPager.dispatchTouchEvent(event)

}

}

}

class ScaleInOutTransformer(private val viewScale: Float = 0.8F, private val marginScale: Float = 0.1F) : ABaseTransformer() {

override fun onTransform(page: View, position: Float) {

val scale = calValScale(position)

page.scaleX = scale

page.scaleY = scale

page.pivotY = page.height / 2F

page.pivotX = page.width / 2f

page.translationX = marginScale * page.width * position

}

private fun calValScale(position: Float): Float {

return (1 - position.absoluteValue * (1 - viewScale))

}

}

使用的时候调用BannerUtil.galleryStyle()就行