我正在尝试将我现有的项目移植到材料设计中,但无法理解RecyclerView的实现。我的旧代码使用列表视图,但我想要像列表一样的 GMail 应用程序。
我已经阅读了大量的教程,但其中大多数要么跳过ItemDecoration
部分,要么跳过ClickListener
部分。 不同的教程具有完全不同的实现,代码各不相同,以至于我无法理解在哪里放置什么。
我在下面苦苦挣扎,我通过阅读各种教程编译:
- 适配器:
我的适配器代码如下:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> { private final Context mContext; private List<String> mData1, mData2; public MyAdapter(Context mContext, String[] data1,String[] data2) { this.mContext = mContext; if (data1 != null) mData1 = new ArrayList<String>(Arrays.asList(data1)); else mData1 = new ArrayList<String>(); if (data2 != null) mData2 = new ArrayList<String>(Arrays.asList(data2)); else mData2 = new ArrayList<String>(); } public void add(String s,int position) { position = position == -1 ? getItemCount() : position; mData1.add(position,s); notifyItemInserted(position); } public void remove(int position){ if (position < getItemCount() ) { mData1.remove(position); notifyItemRemoved(position); } } @Override public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) { LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext()); View itemView = inflater.inflate(R.layout.list_item,viewGroup,false); return new MyViewHolder(itemView); } @Override public void onBindViewHolder(MyViewHolder myViewHolder, int position) { myViewHolder.tv1.setText(mData1.get(position)); myViewHolder.tv2.setText(mData2.get(position)); myViewHolder.setClickListener(new MyViewHolder.ClickListener() { @Override public void onClick(View v, int pos) { Toast.makeText(mContext,"The selected position is: "+ pos,Toast.LENGTH_SHORT).show(); } }); } @Override public int getItemCount() { return mData1.size(); } public static class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { protected TextView tv1; protected TextView tv2; ClickListener clickListener; public MyViewHolder(View itemView) { super(itemView); tv1 = (TextView) itemView.findViewById(R.id.txt1); tv2 = (TextView) itemView.findViewById(R.id.txt2); } @Override public void onClick(View v) { } public void onClick(View v, int pos) { clickListener.onClick(v,getPosition()); } public void setClickListener(ClickListener clickListener) { this.clickListener = clickListener; } public interface ClickListener { public void onClick(View v,int pos); } } }
ItemDecoration
从这里复制:https://gist.github.com/alexfu/0f464fc3742f134ccd1e。但是我真的需要这么大的类来在列表项之间放置简单的分隔符吗?如果我想自己实现代码怎么办?我仍然无法弄清楚
OnClickListener
.首先,我想要一个简单的OnClickListener
就像ListView.OnClickListener
一样。当前OnClickListener
是从教程编译的,但不起作用。
完整代码在这里:https://github.com/pauldmps/MaterialDesign/
回收器查看适配器示例:
-
适配器问题可以使用以下代码解决:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> { private final Context mContext; private List<String> mData1, mData2; public MyAdapter(Context mContext, String[] data1, String[] data2) { this.mContext = mContext; if (data1 != null) mData1 = new ArrayList<String>(Arrays.asList(data1)); else mData1 = new ArrayList<String>(); if (data2 != null) mData2 = new ArrayList<String>(Arrays.asList(data2)); else mData2 = new ArrayList<String>(); } public void add(String s, int position) { position = position == -1 ? getItemCount() : position; mData1.add(position, s); notifyItemInserted(position); } public void remove(int position) { if (position < getItemCount()) { mData1.remove(position); notifyItemRemoved(position); } } @Override public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) { LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext()); View itemView = inflater.inflate(R.layout.list_item, viewGroup, false); return new MyViewHolder(itemView); } @Override public void onBindViewHolder(MyViewHolder myViewHolder, final int position) { myViewHolder.tv1.setText(mData1.get(position)); myViewHolder.tv2.setText(mData2.get(position)); myViewHolder.itemView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub clickListener.onClick(v, position); } }); } @Override public int getItemCount() { return mData1.size(); } ClickListener clickListener; public void setClickListener(ClickListener clickListener) { this.clickListener = clickListener; } public interface ClickListener { public void onClick(View v, int pos); } public static class MyViewHolder extends RecyclerView.ViewHolder { protected TextView tv1; protected TextView tv2; public MyViewHolder(View itemView) { super(itemView); tv1 = (TextView) itemView.findViewById(R.id.txt1); tv2 = (TextView) itemView.findViewById(R.id.txt2); } } }
用法如下:
MyAdapter adapter=....;
adapter.setClickListener(new ClickListener() {
@Override
public void onClick(View v, int pos) {
// do whatever you want
}
});
没有任何简单的方法可以做到这一点。但我建议您一种解决方法。将下面的视图添加为
list_item.xml
底部的分隔线。<View android:layout_width="wrap_content" android:layout_height="0.5dip" android:background="@color/light_gray"/>
项目单击侦听器也在上面的第 1 点中得到解决。
我希望这对你有所帮助。
下面是使用简单库实现回收器视图的示例
在build.gradle
中添加此行
implementation 'com.hereshem.lib:awesomelib:2.0.1'
在活动中创建回收器视图布局
<com.hereshem.lib.recycler.MyRecyclerView
android:id="@+id/recycler"
app:layoutManager="LinearLayoutManager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
通过传递视图持有人支持的类来创建视图持有人
public static class EVHolder extends MyViewHolder<Events> {
TextView date, title, summary;
public EVHolder(View v) {
super(v);
date = v.findViewById(R.id.date);
title = v.findViewById(R.id.title);
summary = v.findViewById(R.id.summary);
}
@Override
public void bindView(Events c) {
date.setText(c.date);
title.setText(c.title);
summary.setText(c.summary);
}
}
创建行很少的项列表变量和适配器
List<Events> items = new ArrayList<>();
MyRecyclerView recycler = findViewById(R.id.recycler);
RecyclerViewAdapter adapter = new RecyclerViewAdapter(this, items, EVHolder.class, R.layout.row_event);
recycler.setAdapter(adapter);
点击监听器可以添加以下行
recycler.setOnItemClickListener(new MyRecyclerView.OnItemClickListener() {
@Override
public void onItemClick(int position) {
Toast.makeText(MainActivity.this, "Recycler Item Clicked " + position, Toast.LENGTH_SHORT).show();
}
});
更多示例可以在这里找到
希望这对:)有所帮助