具体介绍见: 使用RecyclerView实现ListView,GridView的效果(上下,左右滑动)
MainActivity:
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.util.Log;
import android.view.View;
import java.util.ArrayList;
/**
* 再循环视图,内部实现了复用
*/
public class MainActivity extends AppCompatActivity {
/**
* 复用视图的控件
*/
private RecyclerView recyclerView;
/**
* 显示的数据
*/
private ArrayList<String> mDatas;
/**
* RecyclerView的适配器
*/
private MyRecyclerViewAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//1.找到控件
recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
//2.声名为瀑布流的布局方式: 3列,垂直方向
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
//3.为recyclerView设置布局管理器
recyclerView.setLayoutManager(staggeredGridLayoutManager);
initData();//初始化数据
//3.创建适配器
adapter = new MyRecyclerViewAdapter(this, mDatas);
//设置添加,移除item的动画,DefaultItemAnimator为默认的
recyclerView.setItemAnimator(new DefaultItemAnimator());
//4.设置适配器
recyclerView.setAdapter(adapter);
//添加点击事件
adapter.setOnItemClickListener(new MyRecyclerViewAdapter.OnRecyclerItemClickListener() {
@Override
public void onItemClick(View view, int position) {
//Toast.makeText(MainActivity.this,"单击了:"+mDatas.get(position),Toast.LENGTH_SHORT).show();
adapter.addItem(position,"添加的内容");
Log.i("tag", "onItemClick: "+position);
Log.i("tag", "集合: "+mDatas.toString());
}
});
//设置长按事件
adapter.setOnItemLongClickListener(new MyRecyclerViewAdapter.onRecyclerItemLongClickListener() {
@Override
public void onItemLongClick(View view, int position) {
//Toast.makeText(MainActivity.this,"长按了:"+mDatas.get(position),Toast.LENGTH_SHORT).show();
adapter.removeItem(position);
Log.i("tag", "onItemLongClick: "+position);
Log.i("tag", "集合: "+mDatas.toString());
}
});
}
//初始化数据
protected void initData(){
mDatas = new ArrayList<String>();
for (int i = 'A'; i < 'z'; i++){
mDatas.add("" + (char) i);
}
}
}
适配器,MyRecyclerViewAdapter
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.ArrayList;
import java.util.List;
import java.util.Random;
/**
* 实现瀑布流效果的适配器
*/
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.MyViewHolder> {
private Context context;
private List<String> list;//数据
private List<Integer> heightList;//装产出的随机数
private OnRecyclerItemClickListener mOnItemClickListener;//单击事件
private onRecyclerItemLongClickListener mOnItemLongClickListener;//长按事件
public MyRecyclerViewAdapter(Context context, List<String> list) {
this.context = context;
this.list = list;
//记录为每个控件产生的随机高度,避免滑回到顶部出现空白
heightList = new ArrayList<>();
for (int i = 0; i < list.size(); i++) {
int height = new Random().nextInt(200) + 100;//[100,300)的随机数
heightList.add(height);
}
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//找到item的布局
View view= LayoutInflater.from(context).inflate(R.layout.recycler_item_layout,parent,false);
return new MyViewHolder(view);//将布局设置给holder
}
@Override
public int getItemCount() {
return list.size();
}
/**
* 绑定视图到holder,就如同ListView的getView(),但是这里已经把复用实现了,我们只需要填充数据就行.
* 由于在复用的时候都是调用该方法填充数据,但是上滑的时候,又会随机产生高度设置到控件上,这样当滑
* 到顶部可能就会看到一片空白,因为后面随机产生的高度和之前的高度不一样,就不能填充屏幕了,所以
* 需要记录每个控件产生的随机高度,然后在复用的时候再设置上去
*/
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
//填充数据
holder.textView.setText(list.get(position)+"");
//由于需要实现瀑布流的效果,所以就需要动态的改变控件的高度了
ViewGroup.LayoutParams params = holder.textView.getLayoutParams();
params.height=heightList.get(position);
holder.textView.setLayoutParams(params);
//设置单击事件
if(mOnItemClickListener !=null){
holder.textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//这里是为textView设置了单击事件,回调出去
//mOnItemClickListener.onItemClick(v,position);这里需要获取布局中的position,不然乱序
mOnItemClickListener.onItemClick(v,holder.getLayoutPosition());
}
});
}
//长按事件
if(mOnItemLongClickListener != null){
holder.textView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
//回调出去
mOnItemLongClickListener.onItemLongClick(v,holder.getLayoutPosition());
return true;//不返回true,松手还会去执行单击事件
}
});
}
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView textView;
public MyViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.textView);
}
}
/**
* 处理item的点击事件,因为recycler没有提供单击事件,所以只能自己写了
*/
interface OnRecyclerItemClickListener {
public void onItemClick(View view, int position);
}
/**
* 长按事件
*/
interface onRecyclerItemLongClickListener{
public void onItemLongClick(View view, int position);
}
/**
* 暴露给外面的设置单击事件
*/
public void setOnItemClickListener(OnRecyclerItemClickListener onItemClickListener){
mOnItemClickListener = onItemClickListener;
}
/**
* 暴露给外面的长按事件
*/
public void setOnItemLongClickListener(onRecyclerItemLongClickListener onItemLongClickListener){
mOnItemLongClickListener = onItemLongClickListener;
}
/**
* 向指定位置添加元素
*/
public void addItem(int position, String value) {
if(position > list.size()) {
position = list.size();
}
if(position < 0) {
position = 0;
}
/**
* 使用notifyItemInserted/notifyItemRemoved会有动画效果
* 而使用notifyDataSetChanged()则没有
*/
list.add(position, value);//在集合中添加这条数据
heightList.add(position,new Random().nextInt(200) + 100);//添加一个随机高度,会在onBindViewHolder方法中得到设置
notifyItemInserted(position);//通知插入了数据
}
/**
* 移除指定位置元素
*/
public String removeItem(int position) {
if(position > list.size()-1) {
return null;
}
heightList.remove(position);//删除添加的高度
String value = list.remove(position);//所以还需要手动在集合中删除一次
notifyItemRemoved(position);//通知删除了数据,但是没有删除list集合中的数据
return value;
}
}
主布局,activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.workspace.my.recyclerviewtest.MainActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>
</RelativeLayout>
Item布局文件,recycler_item_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/textView"
android:textSize="30sp"
android:gravity="center"
android:layout_margin="3dp"
android:background="#ffcccc"
android:layout_width="match_parent"
android:layout_height="200dp" />
</LinearLayout>
效果如下: