android基础开发之RecycleView(1)---基本使用方式

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