Android RecyclerView

一、XML 布局文件

<android.support.v7.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:overScrollMode="never">
</android.support.v7.widget.RecyclerView>

二、Adapter 适配器

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.bumptech.glide.Glide;
import java.util.ArrayList;
import java.util.List;

public class SubmitAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private List<Submit> mSubmitRecies = new ArrayList<>();
    private Context mContext;

    public SubmitAdapter(List<Submit> Submit) {
        mSubmitRecies = Submit;
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        mContext = parent.getContext();
        LayoutInflater inflater = LayoutInflater.from(mContext);
        switch (viewType) {
            case 0:
                View view = inflater.inflate(R.layout.adapter_submit_image, parent, false);
                return new SubmitViewHolder(view);
            case 1:
                View view1 = inflater.inflate(R.layout.adapter_submit_add, parent, false);
                return new SubmitViewHolder2(view1);
            default:
                return null;
        }
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, final int position) {
        int type = getItemViewType(position);
        switch (type) {
            case 0:
                ((SubmitViewHolder) holder).mTextView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        mSubmitRecies.remove(position);
                        notifyDataSetChanged();
                    }
                });
                Glide.with(mContext)
                        .load(mSubmitRecies.get(position).getUrl())
                        .into(((SubmitViewHolder) holder).mImageView);
                break;
            case 1:
                ((SubmitViewHolder2)holder).mIconFontTextView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        if(mOnAddClickListener!=null){
                            mOnAddClickListener.onAddClick(v);
                        }
                    }
                });
                break;
            default:
                break;
        }
    }

    @Override
    public int getItemCount() {
        return mSubmitRecies.size();
    }

    @Override
    public int getItemViewType(int position) {
        return mSubmitRecies.get(position).getType();
    }

    static class SubmitViewHolder extends RecyclerView.ViewHolder {

        ImageView mImageView;
        IconFontTextView mTextView;

        public SubmitViewHolder(View itemView) {
            super(itemView);
            AutoUtils.autoSize(itemView);
            mImageView = itemView.findViewById(R.id.widget_upload_image);
            mTextView = itemView.findViewById(R.id.widget_upload_cancel);
        }
    }

    static class SubmitViewHolder2 extends RecyclerView.ViewHolder{

        IconFontTextView mIconFontTextView;

        public SubmitViewHolder2(View itemView) {
            super(itemView);
            AutoUtils.autoSize(itemView);
            mIconFontTextView = itemView.findViewById(R.id.adapter_submit_add);
        }
    }

    public void addItem(String url, int type) {
        mSubmitRecies.add(0,new Submit(url,type));
        notifyDataSetChanged();
    }

    private OnAddClickListener mOnAddClickListener;

    public void setOnAddClickListener(OnAddClickListener onAddClickListener){
        mOnAddClickListener = onAddClickListener;
    }

    public interface OnAddClickListener{
        void onAddClick(View v);
    }
}

三、ItemDecoration 分割线

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.WindowManager;

public class ItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;

    private int mOrientation;

    public ItemDecoration(Context context, int orientation) {
        final TypedArray array = context.obtainStyledAttributes(ATTRS);
        mDivider = array.getDrawable(0);
        array.recycle();
        setOrientation(orientation);
    }

    public void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
                if (mOrientation == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }

    public void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft() + getWidth(30);
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount() - 1;
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            android.support.v7.widget.RecyclerView v = new android.support.v7.widget.RecyclerView(parent.getContext());
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            //final int bottom = top + mDivider.getIntrinsicHeight();
            final int bottom = top + 1;
            mDivider.setBounds(left, top, right, bottom);
            mDivider.setColorFilter(PileApplication.getPileContext().getResources().getColor(R.color.color_edeff3), PorterDuff.Mode.SRC);
            mDivider.draw(c);
        }
    }

    public int getWidth(int demin) {
        WindowManager manager = (WindowManager) PileApplication.getPileContext().getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics metrics = new DisplayMetrics();
        manager.getDefaultDisplay().getMetrics(metrics);
        return metrics.widthPixels * demin / 750;
    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount() - 1;
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        if (mOrientation == VERTICAL_LIST) {
            //outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
            int lastPosition = state.getItemCount() - 1;
            int position = parent.getChildAdapterPosition(view);
            if (position < lastPosition) {
                outRect.set(0, 0, 0, 1);
            } else {
                outRect.set(0, 0, 0, 0);
            }
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}

四、初始化渲染

List<Submit> mSubmitRecies = new ArrayList<>();
mSubmitRecies.add(new Submit("url",1));
mSubmitAdapter = new SubmitAdapter(mSubmitRecies);
mRecyclerView.setAdapter(mSubmitAdapter);
GridLayoutManager manager = new GridLayoutManager(this,4);
mRecyclerView.setLayoutManager(manager);

recyclerView.setNestedScrollingEnabled(false); -> 解决滑动冲突
recyclerView.canScrollVertically(1); -> 是否能向下滚动
recyclerView.canScrollVertically(-1); -> 是否能向上滚动
recyclerView.canScrollHorizontally(1); -> 是否能向右滚动
recyclerView.canScrollHorizontally(-1); -> 是否能向左滚动
holder.setIsRecyclable(false); -> item设置不回收