先看看viewpager怎麼實現的，自定義繼承viewpager 。

之前看到csdn覺得一個寫的不錯，，有很多方法來實現，，可以看看這些部落格

Android ViewPager 垂直滑動 縱向滑動 VerticalViewPager

可以繼續看看這個原始stackoverflow這個裡面有很種實現方法，這裡舉例兩個寫法這些都是照搬過來的

import android.support.v4.view.ViewPager;    

public class VerticalViewPager extends ViewPager {

    public VerticalViewPager(Context context) {
        this(context, null);
    }

    public VerticalViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    @Override
    public boolean canScrollHorizontally(int direction) {
        return false;
    }

    @Override
    public boolean canScrollVertically(int direction) {
        return super.canScrollHorizontally(direction);
    }

    private void init() {
        setPageTransformer(true, new VerticalPageTransformer());
        setOverScrollMode(View.OVER_SCROLL_NEVER);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        final boolean toIntercept = super.onInterceptTouchEvent(flipXY(ev));
        flipXY(ev);
        return toIntercept;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        final boolean toHandle = super.onTouchEvent(flipXY(ev));
        flipXY(ev);
        return toHandle;
    }

    private MotionEvent flipXY(MotionEvent ev) {
        final float width = getWidth();
        final float height = getHeight();
        final float x = (ev.getY() / height) * width;
        final float y = (ev.getX() / width) * height;
        ev.setLocation(x, y);
        return ev;
    }

    private static final class VerticalPageTransformer implements ViewPager.PageTransformer {
        @Override
        public void transformPage(View view, float position) {
            final int pageWidth = view.getWidth();
            final int pageHeight = view.getHeight();
            if (position < -1) {
                view.setAlpha(0);
            } else if (position <= 1) {
                view.setAlpha(1);
                view.setTranslationX(pageWidth * -position);
                float yPosition = position * pageHeight;
                view.setTranslationY(yPosition);
            } else {
                view.setAlpha(0);
            }
        }
    }
}
 

如果看舉例用法就點開上面的網址第二個

再看看第二個方法，，親測有用，，

來來介紹：

You can use a ViewPager.PageTransformer to give the illusion of a vertical ViewPager. To achieve scrolling with a vertical instead of a horizontal drag you will have to override ViewPager's default touch events and swap the coordinates of MotionEvents prior to handling them, 

你可以使用ViewPager。PageTransformer提供垂直檢視頁導航的錯覺。要實現垂直滾動而不是水平拖動，您必須覆蓋ViewPager的預設觸控事件，並在處理它們之前交換MotionEvents的座標，

import android.content.Context
import android.support.v4.view.ViewPager
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View


/**
 * Created by Administrator on 2018/8/9/009.
 */
class VerticalViewPager : ViewPager {

    constructor(context: Context?) : super(context){
        init()
    }
    constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs){
        init()
    }


    private fun init() {
        // The majority of the magic happens here
        setPageTransformer(true, VerticalPageTransformer())
        // The easiest way to get rid of the overscroll drawing that happens on the left and right
        overScrollMode = View.OVER_SCROLL_NEVER
    }

    private inner class VerticalPageTransformer : ViewPager.PageTransformer {

        override fun transformPage(view: View, position: Float) {

            if (position < -1) { // [-Infinity,-1)
                // This page is way off-screen to the left.
                view.alpha = 0f

            } else if (position <= 1) { // [-1,1]
                view.alpha = 1f

                // Counteract the default slide transition
                view.translationX = view.width * -position

                //set Y position to swipe in from top
                val yPosition = position * view.height
                view.translationY = yPosition

            } else { // (1,+Infinity]
                // This page is way off-screen to the right.
                view.alpha = 0f
            }
        }
    }

    /**
     * Swaps the X and Y coordinates of your touch event.
     */
    private fun swapXY(ev: MotionEvent): MotionEvent {
        val width = width.toFloat()
        val height = height.toFloat()

        val newX = ev.y / height * width
        val newY = ev.x / width * height

        ev.setLocation(newX, newY)

        return ev
    }

    override fun onInterceptTouchEvent(ev: MotionEvent): Boolean {
        val intercepted = super.onInterceptTouchEvent(swapXY(ev))
        swapXY(ev) // return touch coordinates to original reference frame for any child views
        return intercepted
    }

    override fun onTouchEvent(ev: MotionEvent): Boolean {
        return super.onTouchEvent(swapXY(ev))
    }

}
 

如果需要水平裡面 指向