Android 中RecyclerView通用适配器的实现
前言:
SDK的5.0版本出来已经N久了,可以说是已经经过许多人的检验了,里面的新控件不能说是非常完美,但也是非常好用了,其中最让我喜爱的就是RecyclerView了,可以完美替代ListView和GridView(除了添加headerview和footview了,网上有许多解决方式。这个下面会以一种简单的方式顺带解决,肯定为大家省心),而且可以代码动态切换这两种布局方式以及瀑布流布局。相关切换方式网上有很多,大家自行搜索,我就不贴连接了。
相信大家在之前使用listview时肯定一直很厌烦重复编写无数的adapter,当然有那么一部分机智如我的人肯定一直使用着万能适配器。然而RecyclerView要求我们必须使用ViewHolder来实现adapter。这就让许多用惯了万能适配器的人不爽了。今天我就提供一直基于listview万能适配器的实现原理来改良实现的RecyclerView的通用适配器,由于不是教学,切代码比较简单,就不分段讲解了,相信大家看注释就能看懂。
一共两个类,一个是继承了系统的Android.support.v7.widget.RecyclerView.ViewHolder所实现的RViewHolder类,通过他实现任意控件的缓存一个是继承了android.support.v7.widget.RecyclerView.Adapter所实现的RbaseAdapter类。
实现代码:
RViewHolder
import android.content.Context;
import android.graphics.Bitmap;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
public class RViewHolder extends ViewHolder {
private Context mContext;
private View mConvertView;
private SparseArray mViews;
public RViewHolder(View itemView) {
super(itemView);
mConvertView = itemView;
this.mViews = new SparseArray();
}
public static RViewHolder get(Context context, ViewGroup parent, int layoutId, int position) {
View view = LayoutInflater.from(context).inflate(layoutId, parent, false);
return new RViewHolder(view);
}
public T getView(int viewId) {
View view = mViews.get(viewId);
if (view == null) {
view = mConvertView.findViewById(viewId);
mViews.put(viewId, view);
}
return (T) view;
}
public ViewHolder setText(int viewId, String text) {
TextView view = getView(viewId);
view.setText(text);
return this;
}
public ViewHolder setImageResource(int viewId, int drawableId) {
ImageView view = getView(viewId);
view.setImageResource(drawableId);
return this;
}
public ViewHolder setImageBitmap(int viewId, Bitmap bm) {
ImageView view = getView(viewId);
view.setImageBitmap(bm);
return this;
}
public View getConvertView() {
return mConvertView;
}
}
这里是RbaseAdapter
import java.util.ArrayList; import java.util.Collection; import java.util.List; import android.content.Context; import android.support.v7.widget.RecyclerView.Adapter; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.LinearLayout; public abstract class RbaseAdapterextends Adapter { private Context mContext; private List list; protected LayoutInflater mInflater; private int mItemLayoutId; public RbaseAdapter(Context context) { // TODO Auto-generated constructor stub this.mContext = context; this.mInflater = LayoutInflater.from(mContext); this.mItemLayoutId = new LinearLayout(mContext).getId(); this.list = new ArrayList (); } public RbaseAdapter(Context context, List list) { // TODO Auto-generated constructor stub this.mContext = context; this.mInflater = LayoutInflater.from(mContext); this.mItemLayoutId = new LinearLayout(mContext).getId(); this.list = list; } public RbaseAdapter(Context context, List list, int itemLayoutId) { this.mContext = context; this.mInflater = LayoutInflater.from(mContext); this.mItemLayoutId = itemLayoutId; this.list = list; } public RbaseAdapter(Context context, int itemLayoutId) { this.mContext = context; this.mInflater = LayoutInflater.from(mContext); this.mItemLayoutId = itemLayoutId; this.list = new ArrayList (); } public void setitemLayoutId(int itemLayoutId) { this.mItemLayoutId = itemLayoutId; } public List getList() { return this.list; } public void appendList(List list) { // TODO Auto-generated method stub this.list = list; notifyDataSetChanged(); } public void addList(List list2) { // TODO Auto-generated method stub this.list.addAll((Collection extends T>) list2); notifyDataSetChanged(); } @Override public int getItemCount() { return list.size(); } boolean hasHeader = false; boolean hasFooter = false; View headerView; View footerView; public void setHeaderView(View headerView) { hasHeader=true; this.headerView = headerView; } public void setFooterView(View footerView) { hasFooter = true; this.footerView = footerView; } public View getHeaderView() { return headerView; } public View getFooterView() { return footerView; } @Override public void onBindViewHolder(RViewHolder holder, int position) { if (hasHeader && position == 0) { return; } else if (hasFooter && position == (list.size() + (hasHeader ? 1 : 0))) { return; } else convert(holder, (T) list.get(position)); } @Override public RViewHolder onCreateViewHolder(ViewGroup parent, int position) { if (hasHeader && position == 0) { return new RViewHolder(headerView); } else if (hasFooter && position == (list.size() + (hasHeader ? 1 : 0))) { return new RViewHolder(footerView); } else return RViewHolder.get(mContext, parent, mItemLayoutId, position); } //这里定义抽象方法,我们在匿名内部类实现的时候实现此方法来调用控件 public abstract void convert(RViewHolder holder, T item); }
对于RbaseAdapter稍微讲解下,首先是泛型,这样任何对象类型都可以使用,再来就是前面提到的headerview和footerview的解决,可以看到RbaseAdapter里面定义了几个方法,通过position的不同来加载不同的布局的思想来添加headerview和footerview。
Activity里面调用
recyclerView.setAdapter(new RbaseAdapter(mContext, R.layout.virtual_win_users_list_item) { @Override public void convert(RViewHolder holder, VirtualWinsBean item) { if (Util.checkNULL(item.getNick_name())) { holder.setText(R.id.name, Util.HidePhone(item.getPhone() + "")); } else { holder.setText(R.id.name, item.getNick_name()); } RoundImageView networkImageView = holder.getView(R.id.photo); networkImageView.setLoadingImage(R.drawable.header_def); networkImageView.setDefultImage(R.drawable.header_def); networkImageView.LoadUrl(U.g(item.getFile_url())); } });
感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!



