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
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
其他回答
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);
}
在kotlin中使用构造函数实现
初始化你的RecyclerView构造函数,如下所示:
class ListAdapter(
c: Context,
private var list: List<Project>,
private val itemClick: (Project) -> Unit
) : RecyclerView.Adapter<ListAdapter.ViewHolder>()
在onCreateViewHolder中使用itemClick返回:
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int):ProjectViewHolder {
val view = inflater.inflate(R.layout.list_item, parent, false)
return ViewHolder(view, itemClick)
}
你的onBindViewHolder:
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bindProject(list[position])
}
然后用ViewHolder类创建bindProject函数。
class ViewHolder(
view: View,
private val itemClick: (Project) -> Unit
) : RecyclerView.ViewHolder(view) {
private val clientTextCount = 7
val titleTextView: TextView = view.projectTitleTextView
fun bindProject(project: Project) {
with(project) {
titleTextView.text = name
itemView.setOnClickListener { itemClick(this) }
}
}
}
最后在您的活动中用lazy初始化适配器
private val adapter: ListAdapter by lazy {
ListAdapter(this, projectList, {
// Here you can implement your onClick function.
})
}
在适配器中为RecyclerView添加新列表初始化以下方法:
fun setProjects(projects: List<Project>) {
projectList = projects
notifyDataSetChanged()
}
在你的活动中调用setProjects方法:
adapter.setProjects(projects)
就是这样。
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
...
}
很简单,添加这个类:
public class OnItemClickListener implements View.OnClickListener {
private int position;
private OnItemClickCallback onItemClickCallback;
public OnItemClickListener(int position, OnItemClickCallback onItemClickCallback) {
this.position = position;
this.onItemClickCallback = onItemClickCallback;
}
@Override
public void onClick(View view) {
onItemClickCallback.onItemClicked(view, position);
}
public interface OnItemClickCallback {
void onItemClicked(View view, int position);
}
}
获取一个'OnItemClickCallback'接口实例,并把它放在你的activity或fragment中:
private OnItemClickListener.OnItemClickCallback onItemClickCallback = new OnItemClickListener.OnItemClickCallback() {
@Override
public void onItemClicked(View view, int position) {
}
};
然后,将这个回调传递给你的recyclerView:
recyclerView.setAdapter(new SimpleStringRecyclerViewAdapter(Arrays.asList("1", "2", "3"), onItemClickCallback));
最后,这将是你的适配器:
public class SimpleStringRecyclerViewAdapter extends RecyclerView.Adapter<SimpleStringRecyclerViewAdapter.ViewHolder> {
private List<String> mValues;
private OnItemClickListener.OnItemClickCallback onItemClickCallback;
public SimpleStringRecyclerViewAdapter(List<String> items, OnItemClickListener.OnItemClickCallback onItemClickCallback) {
mValues = items;
this.onItemClickCallback = onItemClickCallback;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public final TextView mTextView;
public ViewHolder(View view) {
super(view);
mTextView = (TextView) view.findViewById(R.id.txt_title);
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.mTextView.setText(mValues.get(position));
holder.mTextView.setOnClickListener(new OnItemClickListener(position, onItemClickCallback));
}
@Override
public int getItemCount() {
return mValues.size();
}
}
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