RecyclerView瀑布流

前言

RecylerView三种布局管理器LinearLayoutManager、GridLayoutManager、StaggeredGridLayoutManager对应单行列表、多行列表、瀑布流式布局，都具水平与垂直。

代码

适配器

ViewHolder中设图宽高

package adapter;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import com.self.zsp.rd.R;import java.util.ArrayList;import java.util.List;import entity.ImageBean;import util.DisplayUtils;import util.GlideImageLoader;/** * Created on 2017/12/18. * * @desc select photo adapter */public class ImagePickShowAdapter extends RecyclerView.Adapter<ImagePickShowAdapter.ViewHolder> implements View.OnClickListener, View.OnLongClickListener {    private Context context;    private List<ImageBean> imageBeanList;    private int screenWidth;    private OnRecyclerViewItemClickListener mOnItemClickListener;    private OnRecyclerViewItemLongClickListener mOnItemLongClickListener;    public ImagePickShowAdapter(Context context) {        this.context = context;        imageBeanList = new ArrayList<>();        screenWidth = DisplayUtils.getScreenWidth(context);    }    public void setImageData(List<ImageBean> list) {        this.imageBeanList = list;        getRandomHeight(list);    }    @Override    public int getItemCount() {        if (imageBeanList != null && imageBeanList.size() > 0) {            return imageBeanList.size();        }        return 0;    }    @Override    public void onClick(View v) {        if (mOnItemClickListener != null) {            // Method getTag which get data.            mOnItemClickListener.onItemClick(v, (ImageBean) v.getTag());        }    }    @Override    public boolean onLongClick(View v) {        if (mOnItemLongClickListener != null) {            // Method getTag which get data.            mOnItemLongClickListener.onItemLongClick(v, (ImageBean) v.getTag());        }        return true;    }    public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {        this.mOnItemClickListener = listener;    }    public void setOnItemLongClickListener(OnRecyclerViewItemLongClickListener listener) {        this.mOnItemLongClickListener = listener;    }    public interface OnRecyclerViewItemClickListener {        /**         * 短点         *         * @param view         * @param imageBean         */        void onItemClick(View view, ImageBean imageBean);    }    public interface OnRecyclerViewItemLongClickListener {        /**         * 长点         *         * @param view         * @param imageBean         */        void onItemLongClick(View view, ImageBean imageBean);    }    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        // Get context.        /*context = parent.getContext();*/        // inflate(R.layout.list_item_record,parent,false)不这么写则cardview不适宽        View view = LayoutInflater.from(context).inflate(R.layout.image_pick_show_item, parent, false);        // 为所创View注册点击事件        view.setOnClickListener(this);        view.setOnLongClickListener(this);        return new ImagePickShowAdapter.ViewHolder(view);    }    @Override    public void onBindViewHolder(final ViewHolder holder, int position) {        final ImageBean imageBean = imageBeanList.get(position);        // 数据保存在itemView之Tag中以便点时获取        holder.itemView.setTag(imageBean);        GlideImageLoader.displayByUri(context, imageBean.getPath(), R.drawable.place_holder, holder.ivImageSelect);    }    /**     * 自定义ViewHolder（持每Item界面全部元素）     */    public class ViewHolder extends RecyclerView.ViewHolder {        public ImageView ivImageSelect;        public ViewHolder(final View view) {            super(view);            ivImageSelect = view.findViewById(R.id.ivImagePickShow);            ViewGroup.LayoutParams params = ivImageSelect.getLayoutParams();            // 图宽高            params.width = screenWidth / 2;            params.height = (int) (200 + Math.random() * 400);            ivImageSelect.setLayoutParams(params);        }    }}

布局

<?xml version="1.0" encoding="utf-8"?><android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    app:cardCornerRadius="@dimen/d6"    app:cardElevation="@dimen/d6"    app:cardMaxElevation="@dimen/d12">    <ImageView        android:id="@+id/ivImagePickShow"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:adjustViewBounds="true" /></android.support.v7.widget.CardView>

间距

package util;import android.graphics.Rect;import android.support.v7.widget.RecyclerView;import android.view.View;/** * Created on 2017/10/23. * * @desc recyclerView item space */public class SpaceItemDecoration extends RecyclerView.ItemDecoration {    private int space;    public SpaceItemDecoration(int space) {        this.space = space;    }    @Override    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {        outRect.left = space;        outRect.top = space;        outRect.right = space;        outRect.bottom = space;    }}

package util;import android.graphics.Rect;import android.support.v7.widget.RecyclerView;import android.view.View;/** * Created on 2017/12/21. * * @desc */public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {    private int spanCount;    private int spacing;    private boolean includeEdge;    public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {        this.spanCount = spanCount;        this.spacing = spacing;        this.includeEdge = includeEdge;    }    @Override    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {        // item position        int position = parent.getChildAdapterPosition(view);        // item column        int column = position % spanCount;        if (includeEdge) {            // spacing - column * ((1f / spanCount) * spacing)            outRect.left = spacing - column * spacing / spanCount;            // (column + 1) * ((1f / spanCount) * spacing)            outRect.right = (column + 1) * spacing / spanCount;            if (position < spanCount) {                // top edge                outRect.top = spacing;            }            outRect.bottom = spacing;            // item bottom        } else {            // column * ((1f / spanCount) * spacing)            outRect.left = column * spacing / spanCount;            // spacing - (column + 1) * ((1f /    spanCount) * spacing)            outRect.right = spacing - (column + 1) * spacing / spanCount;            if (position >= spanCount) {                // item top                outRect.top = spacing;            }        }    }}

主代码

private RecyclerView recyclerViewShow;private ImagePickShowAdapter showAdapter;RecyclerView.LayoutManager layoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);recyclerViewShow.setLayoutManager(layoutManager);// 每item内容不改RecyclerView大小，此设提性能recyclerViewShow.setHasFixedSize(true);recyclerViewShow.addItemDecoration(new SpaceItemDecoration(3));showAdapter = new ImagePickShowAdapter(ImagePickerActivity.this);showAdapter.setImageData(imageSelect);if (!showAdapter.hasObservers()) {    recyclerViewShow.setAdapter(showAdapter);} else {    showAdapter.notifyDataSetChanged();}

附

/** * 随高 * * @param list */private void getRandomHeight(List<ImageBean> list) {    height = new ArrayList<>();    for (int i = 0; i < list.size(); i++) {        height.add((int) (300 + Math.random() * 400));    }}