分组
分组效果
image
思路
- 数据部分可以通过内容或者标志位来区分是不是第一个，例子中通过标志位区分
- Adapter中通过getItemViewType方法来获取标志位，并返回int值用于区分
- onCreateViewHolder中通过区分 viewType 来加载不同的布局
实现
Activity中
- initData() 初始化数据，给标志位来区分数据
- 调用SectionItemDecoration中定义的接口实现数据传递
package com.example.tuionf.recyclerviewlearn;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class SectionActivity extends AppCompatActivity {
private RecyclerView sectionRv;
private List<SectionBean> mList = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_section);
initData();
sectionRv = (RecyclerView) findViewById(R.id.section_rv);
sectionRv.setLayoutManager(new LinearLayoutManager(this));
SectionAdapter sectionAdapter = new SectionAdapter(this,mList);
sectionRv.addItemDecoration(new SectionItemDecoration(this, new SectionItemDecoration.DecorationCallback() {
@Override
public boolean isGroupFirst(int position) {
return mList.get(position).isFirst();
}
@Override
public String getGroupFirstLine(int position) {
return mList.get(position).getTag();
}
}));
sectionRv.setAdapter(sectionAdapter);
}
private void initData() {
for (int i = 0; i < 10; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("山西省");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 20; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("辽宁省");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 25; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("河南省");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 29; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("广东省");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 20; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("北京市");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 20; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("天津市");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 20; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("重庆市");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
for (int i = 0; i < 19; i++) {
SectionBean sectionBean = new SectionBean();
sectionBean.setText("--" + i);
sectionBean.setTag("山东省");
if (i == 0){
sectionBean.setFirst(true);
}else {
sectionBean.setFirst(false);
}
mList.add(sectionBean);
}
}
}
SectionAdapter.java中主要是 getItemViewType() 和 onCreateViewHolder()这两个方法
package com.example.tuionf.recyclerviewlearn;
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 java.util.List;
/**
* Created by tuion on 2017/9/7.
*/
public class SectionAdapter extends RecyclerView.Adapter {
private Context mContext;
private List<SectionBean> mList;
public SectionAdapter(Context mContext, List<SectionBean> mList) {
this.mContext = mContext;
this.mList = mList;
}
@Override
public int getItemViewType(int position) {
int viewType;
if (mList.get(position).isFirst()){
viewType = 0; //这个是第一条
}else {
viewType = 1;
}
return viewType;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
MyViewHolder myViewHolder = null;
switch(viewType){
case 0:
myViewHolder = new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.item1,null));
break;
case 1:
myViewHolder = new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.item,null));
break;
}
return myViewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
MyViewHolder myViewHolder = (MyViewHolder) holder;
myViewHolder.textView.setText(mList.get(position).getText());
}
@Override
public int getItemCount() {
return mList.size();
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView textView;
public MyViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.tv);
}
}
}
