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
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);
}
其他回答
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。
我已经看了所有的答案,并不是很满意。我找到了更简单快捷的方法。想分享给未来的读者。
选择单个回收项目中的任何视图。 获取这个View的父视图(确保你施放了合适的ViewGroup) 将onClickListener设置为这个父节点。
示例代码(它是在适配器的onBindViewHolder方法中编写的):
@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) {
ConstraintLayout parent = (ConstraintLayout) holder.title.getParent();
parent.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(context, "Clicked recycler view item at position " + position, Toast.LENGTH_SHORT).show();
}
});
}
对我来说,最干净的方法就是这个。
适配器的构造函数
private class EnvironmentTypeRecyclerViewAdapter extends RecyclerView.Adapter<EnvironmentTypeRecyclerViewAdapter.ViewHolder>
{
private final EnvironmentTypeRecyclerViewAdapterListener mEnvironmentTypeRecyclerViewAdapterListener;
private List<Environment> mEnvironmentsData;
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener
{
public ViewHolder(View v)
{
super(v);
v.setOnClickListener(this);
}
@Override
public void onClick(View v)
{
Environment environment = mEnvironmentsData.get(getAdapterPosition());
if (mEnvironmentTypeRecyclerViewAdapterListener != null && environment != null) {
mEnvironmentTypeRecyclerViewAdapterListener.onListItemSelected(environment);
}
}
public EnvironmentTypeRecyclerViewAdapter(List<SmallCellEnvironment> environments, EnvironmentTypeRecyclerViewAdapterListener environmentTypeRecyclerViewAdapterListener)
{
mEnvironmentTypeRecyclerViewAdapterListener = environmentTypeRecyclerViewAdapterListener;
mEnvironmentsData = environments;
}
}
链接接口
private interface EnvironmentTypeRecyclerViewAdapterListener
{
void onListItemSelected(Environment environment);
}
对我来说,这是最好的方法:
class YourRecyclerAdapter extends RecyclerView.Adapter<ContactViewHolder> implements View.OnClickListener {
...
@Override
public void onClick(View view) {
int itemPosition = vRecycle.getChildPosition(view);
//And use itemPosition to get the item from your collection. This way you dont restrain the ViewHolder with a OnClick callback
}
...
}
我们可以使用Java弱引用来实现这一点。 从语义上讲,视图持有者应该响应click事件或将其委托给正确的响应器。
我们的目标:
Viewholder应该对响应事件的类一无所知,除非它实现了某个接口。 点击处理程序应该得到被点击的视图在RecyclerView中的位置。 我们应该能够辨别视图持有人中单击了哪个视图。 保持所有组件之间的松散耦合,不要造成任何保留周期。
步骤:
Create an interface to handle click responses. Implement this interface in the Activity that will handle the click. Add a member variable in the RecyclerView Adapter to hold the Weak Reference and a constructor that sets it. Do the same in the RecyclerView ViewHolder and add a member variable to keep track of position. Set your on click listeners on any view you'd like in the ViewHolder, then callback to the responder to handle them. Change your onBindViewHolder method to set the position when binding. Pass the responder down to the ViewHolder. In the responder, you can now use getId() on the view to figure out which view was clicked.
这里是一个要点,这样你就可以看到它们是如何组合在一起的: RecyclerView点击处理
推荐文章
- 警告:API ' variable . getjavacompile()'已过时,已被' variable . getjavacompileprovider()'取代
- 安装APK时出现错误
- 在流中使用Java 8 foreach循环移动到下一项
- 访问限制:'Application'类型不是API(必需库rt.jar的限制)
- 用Java计算两个日期之间的天数
- 碎片中的onCreateOptionsMenu
- 如何配置slf4j-simple
- 在Jar文件中运行类
- 带参数的可运行?
- TextView粗体通过XML文件?
- 如何使线性布局的孩子之间的空间?
- 我如何得到一个字符串的前n个字符而不检查大小或出界?
- 我可以在Java中设置enum起始值吗?
- Java中的回调函数
- c#和Java中的泛型有什么不同?和模板在c++ ?