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该文章投稿至Nemo社区   Android  板块 复制链接


自适应LayoutManager

发布于 2017/06/06 15:12 2,342浏览 0回复 7,217

  UI设计追求偏亮,布局上实现越来越复杂,完全没有想想Android程序员的感受了,嵌套中嵌套,也是够了,没有固定的高度,recycleview的高度不在好计算,

办法还是有的,就是重写onMeasure()方法,下面给出AutoLayoutManager和AutoGridLayoutManager 原理上是一样的

package com.zyf.fwms.commonlibrary.base.baseadapter;

import android.content.Context;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

import com.zyf.fwms.commonlibrary.utils.CommonUtils;
import com.zyf.fwms.commonlibrary.utils.LogUtil;

/**
 * 杭州融科网络
 * 刘宇飞创建 on 2017/6/5.
 * 描述:自适应layoutManager
 */

public class AutoLayoutManager extends LinearLayoutManager {
    private Context context;
    private int space;
    public AutoLayoutManager(Context context,int space) {
        super(context);
        this.context=context;
        this.space=space;
    }

    @SuppressWarnings("UnusedDeclaration")
    public AutoLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
    }

    private int[] mMeasuredDimension = new int[2];


    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);
        int width = 0;
        int height = 0;


        for (int i = 0; i < getItemCount(); i++) {

            try {
                measureScrapChild(recycler, i,
                        widthSpec,
                        View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                        mMeasuredDimension);
            } catch (IndexOutOfBoundsException e) {

                e.printStackTrace();
            }

            if (getOrientation() == HORIZONTAL) {
                width = width + mMeasuredDimension[0];
                if (i == 0) {
                    height = mMeasuredDimension[1];
                }
            } else {
                height = height + mMeasuredDimension[1];
                if (i == 0) {
                    width = mMeasuredDimension[0];
                }
            }
        }

        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }
        setMeasuredDimension(widthSpec, height);

    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec, int heightSpec, int[] measuredDimension) {
        View view = recycler.getViewForPosition(position);


        if (view != null) {
            RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom(), p.height);
            view.measure(widthSpec, childHeightSpec);
            measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
            measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin + CommonUtils.dip2px(context,space);
            try {//有点小问题
                recycler.recycleView(view);
            }catch (Exception e){
                LogUtil.getInstance().e(e.getMessage());
            }

        }
    }

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        super.onLayoutChildren(recycler, state);
    }
}
package com.zyf.fwms.commonlibrary.base.baseadapter;

import android.content.Context;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

/**
 * 杭州融科网络
 * 刘宇飞创建 on 2017/6/6.
 * 描述:自适应GridLayoutManager
 */

public class AutoGridLayoutManager extends GridLayoutManager {
    private int mChildPerLines;
    private int[] mMeasuredDimension = new int[2];

    public AutoGridLayoutManager(Context context, int spanCount) {
        super(context, spanCount);
        this.mChildPerLines = spanCount;
    }

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {

        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);
        int height = 0;
        for (int i = 0; i < getItemCount(); ) {
            measureScrapChild(recycler, i,
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    mMeasuredDimension);
            height = height + mMeasuredDimension[1];
            i = i + mChildPerLines;
        }

        // If child view is more than screen size, there is no need to make it wrap content. We can use original onMeasure() so we can scroll view.
        if (height < heightSize) {
            switch (heightMode) {
                case View.MeasureSpec.EXACTLY:
                    height = heightSize;
                case View.MeasureSpec.AT_MOST:
                case View.MeasureSpec.UNSPECIFIED:
            }
            setMeasuredDimension(widthSize, height);
        } else {
            super.onMeasure(recycler, state, widthSpec, heightSpec);
        }
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                   int heightSpec, int[] measuredDimension) {

        View view = recycler.getViewForPosition(position);

        // For adding Item Decor Insets to view
        super.measureChildWithMargins(view, 0, 0);
        if (view != null) {
            RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
            int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight() + getDecoratedLeft(view) + getDecoratedRight(view), p.width);
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom() + getPaddingBottom() + getDecoratedBottom(view), p.height);
            view.measure(childWidthSpec, childHeightSpec);

            // Get decorated measurements
            measuredDimension[0] = getDecoratedMeasuredWidth(view) + p.leftMargin + p.rightMargin;
            measuredDimension[1] = getDecoratedMeasuredHeight(view) + p.bottomMargin + p.topMargin;
            recycler.recycleView(view);
        }
    }
}

看看恶心的三层嵌套:


Screenshot_2017-06-06-15-12-54-575_com

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