RecyclerView添加分割线的两种方法

Demo地址：http://download.csdn.net/detail/baopengjian/9883895

RecycleView在默认显示的时候没有分割线效果，需要手动添加

#1 Item的layout实现

1）item布局：adapter_itemrealize.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="horizontal" android:layout_width="match_parent"

android:layout_height="80dp">

<TextView

android:id="@+id/tv_title"

android:gravity="center_vertical"

android:layout_width="wrap_content"

android:layout_height="match_parent" />

<View

android:layout_alignParentBottom="true"

android:layout_width="match_parent"

android:layout_height="0.5dp"

android:background="@android:color/black"

/>

</RelativeLayout>

Activity布局就是一个RecyclerView：activity_recycleview.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

>

<android.support.v7.widget.RecyclerView

android:background="@android:color/background_light"

android:id="@+id/rv"

android:orientation="horizontal"

android:layout_width="match_parent"

android:layout_height="match_parent" />

</LinearLayout>

2）Adapter 加载

class ItemRealizeAdapter extends RecyclerView.Adapter<ItemRealizeViewHolder>{

private Context mContext;

private List<String> mDatas;

public ItemRealizeAdapter(Context context,List<String> datas){

mContext = context;

mDatas = datas;

}

@Override

public ItemRealizeViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

View view = LayoutInflater.from(mContext).inflate(R.layout.adapter_itemrealize,parent,false);

ItemRealizeViewHolder holder = new ItemRealizeViewHolder(view);

return holder;

}

@Override

public void onBindViewHolder(ItemRealizeViewHolder holder, int position) {

holder.setTitle(String.valueOf(mDatas.get(position)));

}

@Override

public int getItemCount() {

return mDatas.size();

}

}

class ItemRealizeViewHolder extends RecyclerView.ViewHolder{

private TextView tv_title;

public ItemRealizeViewHolder(View itemView) {

super(itemView);

tv_title = itemView.findViewById(R.id.tv_title);

}

public void setTitle(String data){

tv_title.setText(data);

}

}

3）使用

rv = (RecyclerView) findViewById(R.id.rv);

LinearLayoutManager manager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);

rv.setLayoutManager(manager);

List<String> list = new ArrayList<>();

for(int i = 0;i<50;i++){

list.add(String.valueOf(i));

}

ItemRealizeAdapter adapter = new ItemRealizeAdapter(this,list);

rv.setAdapter(adapter);

4）效果图

5）局限性

item垂直方向上要完全盖住RecyclerView，不能有空隙，item的根Layout控件不能设置垂直方向上的Margin，不然分割线对不准

#2 addItemDecorationt实现

adapter和item等和正常一样，只需要Recyclerview 调用方法addItemDecoration

1） 定义ItemDecoration

public class MyDecoration extends RecyclerView.ItemDecoration {

private Context mContext;

private Drawable mDivider;

private int mOrientation;

public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

public static final int[] ATRRS = new int[]{

android.R.attr.listDivider

};

public MyDecoration(Context context,int orientation){

mContext = context;

TypedArray array = context.obtainStyledAttributes(ATRRS);

mDivider = array.getDrawable(0);

array.recycle();

setOrientation(orientation);

}

@Override

public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {

if (mOrientation == HORIZONTAL_LIST){

drawVerticalLine(c, parent, state);

}else {

drawHorizontalLine(c, parent, state);

}

}

private void drawHorizontalLine(Canvas c, RecyclerView parent, RecyclerView.State state) {

int left = parent.getPaddingLeft();

int right = parent.getWidth() - parent.getPaddingRight();

final int childCount = parent.getChildCount();

for (int i = 0; i < childCount; i++){

final View child = parent.getChildAt(i);

//获得child的布局信息

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);

//Log.d("wnw", left + " " + top + " "+right+" "+bottom+" "+i);

}

}

private void drawVerticalLine(Canvas c, RecyclerView parent, RecyclerView.State state) {

int top = parent.getPaddingTop();

int bottom = parent.getHeight() - parent.getPaddingBottom();

final int childCount = parent.getChildCount();

for (int i = 0; i < childCount; i++){

final View child = parent.getChildAt(i);

//获得child的布局信息

final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)child.getLayoutParams();

final int left = child.getRight() + params.rightMargin;

final int right = left + mDivider.getIntrinsicWidth();

mDivider.setBounds(left, top, right, bottom);

mDivider.draw(c);

}

}

@Override

public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {

if(mOrientation == HORIZONTAL_LIST){

//画横线，就是往下偏移一个分割线的高度

outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());

}else {

//画竖线，就是往右偏移一个分割线的宽度

outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);

}

}

public void setOrientation(int orientation) {

if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST){

throw new IllegalArgumentException("invalid orientation"); } mOrientation = orientation;

}

}

2） ItemDecoration需要的资源：

drawable中定义divider.xml：

<?xml version="1.0" encoding="utf-8"?>

<shape xmlns:android="http://schemas.android.com/apk/res/android"

android:shape="rectangle">

<solid android:color="#7b7a7a"/>

<size android:height="1dp"/>

</shape>

style中定义：

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

<item name="android:listDivider">@drawable/divider</item>

...

</style>

3）设置：

MyDecoration decoration = new MyDecoration(this,MyDecoration.VERTICAL_LIST);

rv.addItemDecoration(decoration);

4）效果图：