有人使用RecyclerView找到了一种方法来设置一个onClickListener的项目在RecyclerView? 我想设置一个监听器为每个项目的布局,但这似乎有点太麻烦了 我确信有一种方法让RecyclerView监听onClick事件,但我不能完全弄清楚。
当前回答
别白费力气了!这个特定用例的代码包含在Android Studio附带的Master/Detail Flow启动器项目中。
从Android Studio选择:
文件>新建>新建项目.... 在Phone and Tablet选项卡中选择如下所示的Master/Detail Flow。
用Kotlin或Java创建项目。 利润。
我不会在这里包括谷歌的ootb演示项目的代码,但我会概述谷歌提供的示例中的主要设计方法:
the item OnClickListener is created ONLY ONCE, and is assigned to a field in your RecyclerView.Adapter implementation. in the onBindViewHolder() you should set the same, pre-created onClickListener object on your ViewHolder instance with holder.itemView.setOnClickListener(mOnClickListener) (AVOID creating a new instance on every method call!); if you need to capture clicks on some specific elements inside the ViewHolder then extend ViewHolder and expose the elements you need as fields so that you can attach whatever listeners you need in onBindViewHolder() — and once again, do NOT re-create the listeners on every method call — initialise them as instance fields and attach them as needed. you can use .setTag() in order to pass state to your viewHolder, e.g. holder.itemView.setTag(mValues.get(position)); as used in the demo.
其他回答
基于Jacob Tabak的回答(+1),我能够添加onLongClick监听器:
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongClick(View view, int position);
}
private OnItemClickListener mListener;
private GestureDetector mGestureDetector;
public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
mListener = listener;
mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
@Override
public void onLongPress(MotionEvent e) {
View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null) {
mListener.onItemLongClick(childView, recyclerView.getChildAdapterPosition(childView));
}
}
});
}
@Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
View childView = view.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
}
return false;
}
@Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
然后你可以这样使用它:
recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(getActivity(), recyclerView, new RecyclerItemClickListener.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
// ...
}
@Override
public void onItemLongClick(View view, int position) {
// ...
}
}));
这是我的自定义适配器的完整代码,这段代码将用XML文件“list_item”中定义的列表项膨胀行,它还将在具有各自位置的所有列表项行上执行单击事件。
public class MyCustomAdapter extends RecyclerView.Adapter`<`AdapterMyCustomAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {
public onItemClickListener mListener;
public ViewHolder(View v, onItemClickListener listener) {
super(v);
mListener =listener;
v.setOnClickListener(this);
}
@Override
public void onClick(View v) {
mListener.onRecyclerItemClick(v, getPosition());
}
public static interface onItemClickListener {
public void onRecyclerItemClick(View view , int position);
}
}
@Override
public int getItemCount() {
return 5;
}
@Override
public void onBindViewHolder(ViewHolder holder, int pos) {
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int position) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item, parent, false);
/* here list_item is an xml file we want to inflate ...it is same as we do in case of listview for customization.*/
MyCustomAdapter.ViewHolder vh = new ViewHolder(v, new MyCustomAdapter.ViewHolder.onItemClickListener() {
@Override
public void onRecyclerItemClick(View view, int position) {
System.out.println("clicked on list item at position " +position);
}
});
return vh;
}
}
下面是我的代码片段:
v.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
int newPosition = MainActivity.mRecyclerView.getChildAdapterPosition(v);
Intent cardViewIntent = new Intent(c, MainActivityCards.class);
cardViewIntent.putExtra("Position", newPosition);
c.startActivity(cardViewIntent);
}
});
v是onCreateViewHolder的视图 c为背景信息
Recyclerview适配器与kotlin
在适配器中可以通过两种方式实现项目点击监听器。
第一种方法是使用界面
在你的活动课上:
class YourActivity : AppCompatActivity(), TestAdapter.ClickListener {
...
override fun itemClicked() {
}
...
}
在适配器类中:
class MyAdapter : RecyclerView.Adapter<MyAdapter.MyViewHolder> {
...
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.textView1.setOnClickListener {
clickListener.itemClicked(position)
}
}
...
interface ClickListener {
fun itemClicked(position : Int)
}
...
}
第二种方法是使用callBack调用
在适配器类中:
class MyAdapter(val callBack: (pos:Int) -> Unit) : RecyclerView.Adapter<MyAdapter.MyViewHolder> {
...
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.textView1.setOnClickListener {
callBack(position)
}
}
}
在你的活动课上:
class YourActivity : AppCompatActivity() {
...
val testAdapter = TestAdapter(
callBack = { index ->
})
binding.recyclerView.layoutManager = LinearLayoutManager(this)
binding.recyclerView.adapter = testAdapter
...
}
查看类似的问题@CommonsWare的评论链接到this,它在viewHolder中实现了OnClickListener接口。
下面是ViewHolder的一个简单例子:
/** Declare global with in adapter class. */
TextView textView;
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private ViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
textView = (TextView) view.findViewById(android.R.id.text1);
}
@Override
public void onClick(View view) {
Toast.makeText(view.getContext(), "position = " + getLayoutPosition(), Toast.LENGTH_SHORT).show();
/** Go through each item if you have few items within RecyclerView. */
if (getLayoutPosition() == 0) {
// Do whatever you want here
} else if(getLayoutPosition() == 1) {
// Do whatever you want here
} else if(getLayoutPosition() == 2) {
// Do whatever you want here
}
/** Or you can use For loop if you have long list of items. */
for (int i = 0; i < exampleList.size(); i++) {
// Do whatever you want here
}
}
}
在你的RecyclerView中创建ViewHolder。适配器看起来像这样:
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext())
View view = inflater.inflate(android.R.layout.simple_list_item_1, parent, false);
return new ViewHolder(view);
}
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