RecyclerView的基本使用

1.导入依赖

compile 'com.android.support:recyclerview-v7:21.0.+'

Linearlayout布局：

public class DividerItemDecoration 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 DividerItemDecoration(Context context, int orientation) {        final TypedArray a = context.obtainStyledAttributes(ATTRS);        mDivider = a.getDrawable(0);        a.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) {        if (mOrientation == VERTICAL_LIST) {            drawVertical(c, parent);        } else {            drawHorizontal(c, parent);        }    }    public void drawVertical(Canvas c, RecyclerView parent) {        final int left = parent.getPaddingLeft();        final int right = parent.getWidth() - parent.getPaddingRight();        final int childCount = parent.getChildCount();        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();            mDivider.setBounds(left, top, right, bottom);            mDivider.draw(c);        }    }    public void drawHorizontal(Canvas c, RecyclerView parent) {        final int top = parent.getPaddingTop();        final int bottom = parent.getHeight() - parent.getPaddingBottom();        final int childCount = parent.getChildCount();        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, int itemPosition, RecyclerView parent) {        if (mOrientation == VERTICAL_LIST) {            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());        } else {            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);        }    }}

GridLayout布局

public class DividerGridItemDecoration extends RecyclerView.ItemDecoration{    private static final int[] ATTRS = new int[] { android.R.attr.listDivider };    private Drawable mDivider;    public DividerGridItemDecoration(Context context)    {        final TypedArray a = context.obtainStyledAttributes(ATTRS);        mDivider = a.getDrawable(0);        a.recycle();    }    @Override    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state)    {        drawHorizontal(c, parent);        drawVertical(c, parent);    }    private int getSpanCount(RecyclerView parent)    {        // 列数        int spanCount = -1;        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();        if (layoutManager instanceof GridLayoutManager)        {            spanCount = ((GridLayoutManager) layoutManager).getSpanCount();        } else if (layoutManager instanceof StaggeredGridLayoutManager)        {            spanCount = ((StaggeredGridLayoutManager) layoutManager)                    .getSpanCount();        }        return spanCount;    }    public void drawHorizontal(Canvas c, RecyclerView parent)    {        int childCount = parent.getChildCount();        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.getLeft() - params.leftMargin;            final int right = child.getRight() + params.rightMargin                    + mDivider.getIntrinsicWidth();            final int top = child.getBottom() + params.bottomMargin;            final int bottom = top + mDivider.getIntrinsicHeight();            mDivider.setBounds(left, top, right, bottom);            mDivider.draw(c);        }    }    public void drawVertical(Canvas c, RecyclerView parent)    {        final int childCount = parent.getChildCount();        for (int i = 0; i < childCount; i++)        {            final View child = parent.getChildAt(i);            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child                    .getLayoutParams();            final int top = child.getTop() - params.topMargin;            final int bottom = child.getBottom() + params.bottomMargin;            final int left = child.getRight() + params.rightMargin;            final int right = left + mDivider.getIntrinsicWidth();            mDivider.setBounds(left, top, right, bottom);            mDivider.draw(c);        }    }    private boolean isLastColum(RecyclerView parent, int pos, int spanCount,                                int childCount)    {        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();        if (layoutManager instanceof GridLayoutManager)        {            if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边            {                return true;            }        } else if (layoutManager instanceof StaggeredGridLayoutManager)        {            int orientation = ((StaggeredGridLayoutManager) layoutManager)                    .getOrientation();            if (orientation == StaggeredGridLayoutManager.VERTICAL)            {                if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边                {                    return true;                }            } else            {                childCount = childCount - childCount % spanCount;                if (pos >= childCount)// 如果是最后一列，则不需要绘制右边                    return true;            }        }        return false;    }    private boolean isLastRaw(RecyclerView parent, int pos, int spanCount,                              int childCount)    {        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();        if (layoutManager instanceof GridLayoutManager)        {            childCount = childCount - childCount % spanCount;            if (pos >= childCount)// 如果是最后一行，则不需要绘制底部                return true;        } else if (layoutManager instanceof StaggeredGridLayoutManager)        {            int orientation = ((StaggeredGridLayoutManager) layoutManager)                    .getOrientation();            // StaggeredGridLayoutManager 且纵向滚动            if (orientation == StaggeredGridLayoutManager.VERTICAL)            {                childCount = childCount - childCount % spanCount;                // 如果是最后一行，则不需要绘制底部                if (pos >= childCount)                    return true;            } else            // StaggeredGridLayoutManager 且横向滚动            {                // 如果是最后一行，则不需要绘制底部                if ((pos + 1) % spanCount == 0)                {                    return true;                }            }        }        return false;    }    @Override    public void getItemOffsets(Rect outRect, int itemPosition,                               RecyclerView parent)    {        int spanCount = getSpanCount(parent);        int childCount = parent.getAdapter().getItemCount();        if (isLastRaw(parent, itemPosition, spanCount, childCount))// 如果是最后一行，则不需要绘制底部        {            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);        } else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最后一列，则不需要绘制右边        {            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());        } else        {            outRect.set(0, 0, mDivider.getIntrinsicWidth(),                    mDivider.getIntrinsicHeight());        }    }}

点击的回调接口（看情况）

public interface OnItemClickLitener {    void onItemClick(View view, int position);    void onItemLongClick(View view , int position);}

MainActivity的使用

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.GridLayoutManager;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private Button btn1,btn2;    private RecyclerView mRecyclerView;    private OnItemClickLitener mItemClickListener;    private List<String> mDatas;    private HomeAdapter mAdapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview);        btn1 = (Button) findViewById(R.id.btn1);        btn2 = (Button) findViewById(R.id.btn2);        initData();//        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));        mRecyclerView.setLayoutManager(new GridLayoutManager(this,4));        mRecyclerView.setAdapter(mAdapter = new HomeAdapter());        mRecyclerView.addItemDecoration(new DividerItemDecoration(this,                DividerItemDecoration.VERTICAL_LIST));    }    protected void initData()    {        mDatas = new ArrayList<String>();        for (int i = 'A'; i < 'z'; i++)        {            mDatas.add("" + (char) i);        }        btn1.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                mAdapter.removeData(1);            }        });        btn2.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                mAdapter.addData(1);            }        });    }    class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {        @Override        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {            MyViewHolder holder = new MyViewHolder(LayoutInflater.from(                    MainActivity.this).inflate(R.layout.item_home, parent,                    false));            return holder;        }        @Override        public void onBindViewHolder(final MyViewHolder holder, final int position) {            holder.tv.setText(mDatas.get(position));            holder.tv.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    mAdapter.notifyItemRemoved(position);                    if (null != mItemClickListener) {                        mItemClickListener.onItemClick(holder.tv,                                position);                    }                    Toast.makeText(MainActivity.this,"第几条"+position,Toast.LENGTH_LONG).show();                       //点击条目删除                }            });        }        @Override        public int getItemCount() {            return mDatas.size();        }        class MyViewHolder extends RecyclerView.ViewHolder {            TextView tv;            public MyViewHolder(final View view) {                super(view);                tv = (TextView) view.findViewById(R.id.id_num);                //为item添加普通点击回调                view.setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View v) {                        if (null != mItemClickListener) {                            mItemClickListener.onItemClick(view, getPosition());                        }                    }                });            }        }        public void addData(int position) {            mDatas.add(position, "Insert One");            notifyItemInserted(position);        }        public void removeData(int position) {            mDatas.remove(position);            notifyItemRemoved(position);        }    }}