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
这就是重用View的方法。OnClickListener:
public class TestAdapter extends RecyclerView.Adapter<TestAdapter.MyviewHolder>
implements View.OnClickListener
在ViewHoder中获取项目布局的父视图:
public class MyviewHolder extends RecyclerView.ViewHolder {
LinearLayout linearLayout;
public MyviewHolder(View itemView) {
super(itemView);
linearLayout = itemView.findViewById(R.id.linear_layout_item);
}
}
在onBindViewHolder中设置标签为位置:
@Override
public void onBindViewHolder(MyviewHolder holder, int position) {
holder.linearLayout.setTag(position);
holder.linearLayout.setOnClickListener(this);
}
在你的onClick实现中:
@Override
public void onClick(View v) {
int position = (int) v.getTag();
switch (v.getId()) {
case R.id.linear_layout_item:
// do some thing with position
break;
}
}
其他回答
我是这样做的,没有不必要的类、检测器等。适配器中的简单代码。特别是针对longClick的更好解决方案。
public class PasswordAdapter extends RecyclerView.Adapter<PasswordAdapter.ViewHolder> {
private final ClickListener clickListener;
public PasswordAdapter(ClickListener clickListener) {
this.clickListener = clickListener;
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
TextView name;
public ViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
itemView.setOnLongClickListener(this);
name = (TextView) itemView.findViewById(R.id.card_name);
}
@Override
public void onClick(View v) {
int position = getBindingAdapterPosition();
if (position >= 0) {
clickListener.onItemClick(position, v);
}
}
@Override
public boolean onLongClick(View v) {
int position = getBindingAdapterPosition();
if (position >= 0) {
clickListener.onItemLongClick(position, v);
return true;
}
return false;
}
}
public interface ClickListener {
void onItemClick(int position, View v);
void onItemLongClick(int position, View v);
}
}
然后在片段或活动中,点击:
PasswordAdapter mAdapter = new PasswordAdapter(
new PasswordAdapter.ClickListener() {
@Override
public void onItemClick(int position, View v) {
Log.d(TAG, "onItemClick position: " + position);
}
@Override
public void onItemLongClick(int position, View v) {
Log.d(TAG, "onItemLongClick pos = " + position);
}
}
);
这里有一个策略,它给出了一个类似于ListView实现的结果,因为你可以在活动或片段级别而不是适配器或ViewHolder级别定义侦听器。它还定义了一些抽象类,这些抽象类负责适配器和持有者的大量样板工作。
抽象类
首先,定义一个抽象Holder,它扩展了RecyclerView。并定义了一个泛型数据类型T,用于将数据绑定到视图。bindViews方法将由一个子类实现,用于将数据映射到视图。
public abstract class Holder<T> extends RecyclerView.ViewHolder {
T data;
public Holder(View itemView) {
super(itemView);
}
public void bindData(T data){
this.data = data;
bindViews(data);
}
abstract protected void bindViews(T data);
}
同样,创建一个抽象适配器,扩展RecyclerView.Adapter<Holder<T>>。这定义了3个接口方法中的2个,子类将需要实现最后一个onViewHolderCreated方法。
public abstract class Adapter<T> extends RecyclerView.Adapter<Holder<T>> {
List<T> list = new ArrayList<>();
@Override
public void onBindViewHolder(Holder<T> holder, int position) {
holder.bindData(list.get(position));
}
@Override
public int getItemCount() {
return list.size();
}
public T getItem(int adapterPosition){
return list.get(adapterPosition);
}
}
具体类
现在创建一个扩展Holder的新具体类。该方法只需定义视图并处理绑定。这里我使用ButterKnife库,但请随意使用itemView.findViewById(…)方法代替。
public class PersonHolder extends Holder<Person>{
@Bind(R.id.firstname) TextView firstname;
@Bind(R.id.lastname) TextView lastname;
public PersonHolder(View view){
super(view);
ButterKnife.bind(this, view);
}
@Override
protected void bindViews(Person person) {
firstname.setText(person.firstname);
lastname.setText(person.lastname);
}
}
最后,在持有RecyclerView的Activity或Fragment类中,你会有这样的代码:
// Create adapter, this happens in parent Activity or Fragment of RecyclerView
adapter = new Adapter<Person>(){
@Override
public PersonHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.layout_person_view, parent, false);
PersonHolder holder = new PersonHolder(v);
v.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
int itemPos = holder.getAdapterPosition();
Person person = getItem(itemPos);
// do something with person
EventBus.getDefault().postSticky(new PersonClickedEvent(itemPos, person));
}
});
return holder;
}
};
由于API已经发生了根本性的变化,如果你要为每个项目创建一个OnClickListener,这不会让我感到惊讶。不过也没那么麻烦。在你的RecyclerView的实现中。适配器<MyViewHolder>,你应该有:
private final OnClickListener mOnClickListener = new MyOnClickListener();
@Override
public MyViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) {
View view = LayoutInflater.from(mContext).inflate(R.layout.myview, parent, false);
view.setOnClickListener(mOnClickListener);
return new MyViewHolder(view);
}
onClick方法:
@Override
public void onClick(final View view) {
int itemPosition = mRecyclerView.getChildLayoutPosition(view);
String item = mList.get(itemPosition);
Toast.makeText(mContext, item, Toast.LENGTH_LONG).show();
}
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);
}
通常你在CardView中有多个元素,所以你需要一个布局视图来包装和组织它们。你可以添加一个OnClickListener到那个布局视图。1. 添加一个id到你的布局。在这个例子中是线性布局
<android.support.v7.widget.CardView
.....>
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/card_view_linearLayout">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="name"
android:id="@+id/card_view_name" />
...
</LinearLayout>
</android.support.v7.widget.CardView>
2美元。在你的内部ViewHolder类中获取布局视图。
public static class ViewHolder extends RecyclerView.ViewHolder{
private TextView nameView;
...
private LinearLayout linearLayout;
public ViewHolder(View itemView) {
super(itemView);
nameView = (TextView)itemView.findViewById(R.id.card_view_name);
...
linearLayout = (LinearLayout)itemView.findViewById(R.id.card_view_linearLayout);
}
}
3美元。将监听器添加到onBindViewHolder中的布局中,并使用回调将数据发送到活动或片段(未测试)。
@Override
public void onBindViewHolder(TrackAdapter.ViewHolder holder, final int position) {
String str = mStringList.get(position);
holder.nameView.setText(str);
...
holder.linearLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
callback.itemCallback(mStringList.get(position));
}
});
}
如何使用回调是另一个故事