Android ViewPager自适应高度（tabLayout+viewPager+fragment 内容高度不同时，出现的留白问题）

Android ViewPager自适应高度（tabLayout+viewPager+fragment 内容高度不同时，出现的留白问题）

情景一
将view中最高的高度作为viewPager的高度，这种方法下，所有的view高度都是一样的，高度不足的view就会出现留白问题

package com.example.goubaowang.utils;

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

public class ViewPagerForScrollView extends ViewPager {
    public ViewPagerForScrollView(Context context) {
        super(context);
    }

    public ViewPagerForScrollView(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);
    }
}

然后再布局中引用就行

**可直接进入 解决viewPager和scrollView 此方法也可以解决 **

情景二
在遇到页面高低不一样的时候，根据页面自身的高低来定义viewPager的高度

package com.example.goubaowang.widget;

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

public class AutoHeightViewPager extends ViewPager {

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        // find the current child view
        // and you must cache all the child view
        // use setOffscreenPageLimit(adapter.getCount())
        View view = getChildAt(getCurrentItem());
        if (view != null) {
            // measure the current child view with the specified measure spec
            view.measure(widthMeasureSpec, heightMeasureSpec);
        }

        setMeasuredDimension(getMeasuredWidth(), measureHeight(heightMeasureSpec, view));
    }

    /**
     * Determines the height of this view
     *
     * @param measureSpec A measureSpec packed into an int
     * @param view the base view with already measured height
     *
     * @return The height of the view, honoring constraints from measureSpec
     */
    private int measureHeight(int measureSpec, View view) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {
            result = specSize;
        } else {
            // set the height from the base view if available
            if (view != null) {
                result = view.getMeasuredHeight();
            }
            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        return result;
    }

    /**
     * 单独测量view获取尺寸
     *
     * @param view
     */
    public void measeureView(View view) {

        int intw = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        int inth = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        // 重新测量view
        view.measure(intw, inth);

        // 以上3句可简写成下面一句
        //view.measure(0,0);

        // 获取测量后的view尺寸
        int intwidth = view.getMeasuredWidth();
        int intheight = view.getMeasuredHeight();
    }
}

引用

然后在实现viewPager的监听方法中来给viewPager重置高度

viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
                @Override
                public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

                }

                @Override
                public void onPageSelected(int position) {
                  //  rl_text.setCurrentTab(position);
                    // 切换到当前页面，重置高度
                    viewPager.requestLayout();
                }

                @Override
                public void onPageScrollStateChanged(int state) {

                }
            });

这两种方法希望能帮助到遇到问题的铁铁们，不足之处大家多多提议，谢谢