ScrollView 嵌套ViewPager不能显示

重写 ViewPager 测量方法:

import android.content.Context;

import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.View;
/**
 * author: wu
 * date: on 2018/6/14.
 * describe:ScrollView 嵌套 ViewPager 不能显示
 */

public class CustomViewPager extends ViewPager {
    public CustomViewPager(Context context) {
        super(context);
    }
    public CustomViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = 0;
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            if (h > height)height = h;
        }
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

}

xml 文件中写入:

                    <com.miaomi.miaomiao.utils.discover.CustomViewPager
                        android:id="@+id/viewPager"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content" />