RecyclerView更加优化的复用机制和方便实现UI效果，几乎替代Listview和GridView的使用。但是分割线的实现，需要自己继承ItemDecoration来绘制。
效果图
item的布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_vertical"
android:layout_marginTop="25dp"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="餐饮"
android:id="@+id/txt_title"
android:textSize="16sp"
android:textStyle="bold"
android:textColor="#555555"/>
<ImageView
android:layout_width="36dp"
android:layout_height="36dp"
android:id="@+id/img_title"
android:src="@mipmap/luggage_blue"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="20dp"
android:orientation="vertical"
android:layout_marginBottom="25dp"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="提供航空 餐饮美食"
android:id="@+id/txt_info"
android:textSize="14sp"
android:textColor="#999999"/>
</LinearLayout>
</LinearLayout>
activity_main.xml布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#f1f1f1"
tools:context=".MainActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="50dp"
android:textColor="#ffffff"
android:textSize="18sp"
android:gravity="center"
android:text="RecyclerView实现九宫格"
android:background="#30B8E3"/>
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:gravity="center_vertical"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:orientation="horizontal">
<ImageView
android:layout_width="20dp"
android:layout_height="20dp"
android:src="@mipmap/air_gray"
android:layout_marginRight="8dp"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="航行助手"
android:textStyle="bold"
android:textSize="18sp"/>
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/main_recycleview"
android:divider="#00000000"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/shape_bg"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:layout_marginBottom="15dp">
</android.support.v7.widget.RecyclerView>
</LinearLayout>
</ScrollView>
</LinearLayout>
MainActivity.java代码
package com.davis.recyclerviewdemo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import com.davis.recyclerviewdemo.adapter.CommonDecoration;
import com.davis.recyclerviewdemo.adapter.RecyclerViewAdapter;
import com.davis.recyclerviewdemo.bean.MenuBean;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private RecyclerViewAdapter adapter;
private List<MenuBean> listDatas = new ArrayList<MenuBean>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init(){
recyclerView = (RecyclerView)findViewById(R.id.main_recycleview);
loadMenuData();
recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
recyclerView.addItemDecoration(new CommonDecoration(this));
adapter = new RecyclerViewAdapter(this, listDatas);
recyclerView.setAdapter(adapter);
}
private void loadMenuData(){
listDatas.add(new MenuBean("安检", "快速安检", R.mipmap.check_blue));
listDatas.add(new MenuBean("行李", "提醒行李动态", R.mipmap.luggage_blue));
listDatas.add(new MenuBean("餐饮", "提供航空 餐饮美食", R.mipmap.food_blue));
listDatas.add(new MenuBean("VIP休息", "机场休息室", R.mipmap.vip_blue));
listDatas.add(new MenuBean("机舱服务", "机舱上网 游戏娱乐", R.mipmap.service_blue));
listDatas.add(new MenuBean("更多", "更多信息", R.mipmap.more_blue));
}
}
其中GridLayoutManager用来设置显示列数，CommonDecoration用来绘制分隔线。
CommonDecoration.java代码
package com.davis.recyclerviewdemo.adapter;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;
/**
* Created by Administrator on 2019/4/14.
*/
public class CommonDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
private Drawable mDivider;
public CommonDecoration(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) {
// 如果是最后一列，则不需要绘制右边
if ((pos + 1) % spanCount == 0) {
return true;
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
if (orientation == StaggeredGridLayoutManager.VERTICAL) {
// 如果是最后一列，则不需要绘制右边
if ((pos + 1) % spanCount == 0) {
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) {
int last = childCount % spanCount;
if (last == 0) {
last = spanCount;
}
childCount = childCount - last;
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) {
int last = childCount % spanCount;
if (last == 0) {
last = spanCount;
}
childCount = childCount - last;
// 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 (isLastColum(parent, itemPosition, spanCount, childCount)) {// 如果是最后一列，则不需要绘制右边
if (itemPosition == (childCount - 1)) {
outRect.set(0, 0, 0, 0);
} else {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
}
} else 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 {
outRect.set(0, 0, mDivider.getIntrinsicWidth(),
mDivider.getIntrinsicHeight());
}
}
}
