android基础开发之RecycleView

RecycleView是google为了优化listview，gridview 提供的一个新的控件。

1.android 导入recycleview

在app的gradle里面加入：

dependencies {    compile fileTree(dir: 'libs', include: ['*.jar'])    apt "org.androidannotations:androidannotations:$AAVersion"    compile "org.androidannotations:androidannotations-api:$AAVersion"    testCompile 'junit:junit:4.12'    compile 'com.android.support:recyclerview-v7:23.1.+'    compile 'com.android.support:appcompat-v7:23.1.1'}

其中23为sdk版本号。

2.使用RecycleView

RecycleView主要功能分为几个模块：

adapter 的功能与以前类似。

package com.joyfulmath.sample.javanetwork.androidbase.recycleview.view;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.TextView;import com.joyfulmath.sample.javanetwork.R;import java.util.ArrayList;/** * @author deman.lu * @version on 2016-03-10 14:19 */public class RecycleAdapter extends RecyclerView.Adapter<RecycleAdapter.RecycleViewHolder> {    private Context context;    private ArrayList<String> mDatas;    public RecycleAdapter(Context context,ArrayList<String> mStrings)    {        this.context = context;        this.mDatas = mStrings;    }    @Override    public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        RecycleViewHolder holder = new RecycleViewHolder(LayoutInflater.from(context)            .inflate(R.layout.item_list,parent,false));        return holder;    }    @Override    public void onBindViewHolder(RecycleViewHolder holder, int position) {        holder.tv1.setText(mDatas.get(position));        holder.tv2.setText(mDatas.get(position)+" demo");    }    @Override    public int getItemCount() {        return mDatas.size();    }    class RecycleViewHolder extends RecyclerView.ViewHolder    {        TextView    tv1;        TextView    tv2;        public RecycleViewHolder(View itemView) {            super(itemView);            tv1 = (TextView) itemView.findViewById(R.id.tv_1);            tv2 = (TextView) itemView.findViewById(R.id.tv_2);        }    }}

首先 需要定义一个holder，这个holder是用来优化复用recycleview的item的。此与listview已经非常类似。

其次adapter要实现3个方法：

public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType)　//viewholder 布局代码

public void onBindViewHolder(RecycleViewHolder holder, int position)　　数据处理代码

 public int getItemCount() 　　得到item size

相当熟悉的代码。

 

LayoutManager:

RecycleView 默认支持linearlayoutmanager & gridlayoutmanager

其实就是对应listview & gridview

mRcyV.setLayoutManager(new LinearLayoutManager(this));

    void afterView()    {        mPresenter = new RecyclePresenter();        mRcyV.setLayoutManager(new GridLayoutManager(this,4));        mRcyV.setAdapter(new RecycleAdapter(this, mPresenter.getData()));        mRcyV.addItemDecoration(new RecycleGridItemDecoration(this));    }

ItemDectoration:

本质上是每个itemview的子view。很多时候用途就是定义为 分隔线使用。

1.listview.

public class RecycleItemDecoration 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 RecycleItemDecoration(Context context, int orientation) {        final TypedArray a = context.obtainStyledAttributes(ATTRS);        mDivider = new ColorDrawable(Color.argb(0xff,0xff,0x22,0x33));        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);            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+10);            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);        }    }}

2.gridview 样式：

public class RecycleGridItemDecoration extends RecyclerView.ItemDecoration {    private static final int[] ATTRS = new int[] { android.R.attr.listDivider };    private Drawable mDivider;    public RecycleGridItemDecoration(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());        }    }}

 

最后是activity页面：

@EActivity(R.layout.activity_recycleview_demo)public class RecycleViewDemo extends Activity{    @ViewById(R.id.act_solution_1_lv)    RecyclerView mRcyV;    RecyclePresenter mPresenter;    @AfterViews    void afterView()    {        mPresenter = new RecyclePresenter();        mRcyV.setLayoutManager(new GridLayoutManager(this,4));        mRcyV.setAdapter(new RecycleAdapter(this, mPresenter.getData()));        mRcyV.addItemDecoration(new RecycleGridItemDecoration(this));    }}

ItemAnimator：

recycleview的每一个item的add & delete都是可配置动画的。DefaultItemAnimator是google提供的默认实现方式。

mRcyV.setItemAnimator(new DefaultItemAnimator());

    public void addData(int position) {        mDatas.add(position, "Insert One");        notifyItemInserted(position);    }    public void removeData(int position) {        mDatas.remove(position);        notifyItemRemoved(position);    }

在adapter中实现这2个方法，关键在于notifyItem***， 这2个方法可以触发动画。

recycleview比起listview来说，应该是可以定制更多的东西，尤其是瀑布模式，实现起来效果很炫。

参考：

http://blog.csdn.net/lmj623565791/article/details/45059587