Android 如何在RecyclerView中选择职位?
我正在试验支持库的recyclerview和cards。我有一堆卡片。每张卡的右上角都有一个“x”图标,可以将其移除: 卡片xml,Android 如何在RecyclerView中选择职位?,android,android-support-library,android-recyclerview,android-cardview,Android,Android Support Library,Android Recyclerview,Android Cardview,我正在试验支持库的recyclerview和cards。我有一堆卡片。每张卡的右上角都有一个“x”图标,可以将其移除: 卡片xml,list\u item.xml: <?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="ma
list\u item.xml
:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="5dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/taskDesc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:textSize="40sp"
android:text="hi"/>
<ImageView
android:id="@+id/xImg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:src="@drawable/ic_remove"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
这不起作用,因为您不能设置标记,我也不能从
onClick访问适配器。
将onClickListener
s设置在onBindViewHolder()
上,您可以从那里访问位置。如果在ViewHolder
中设置它们,则除非将位置传递到ViewHolder
编辑
正如pskink
所指出的ViewHolder
有一个getPosition()
所以您最初的操作方式是正确的
单击视图时,您可以在视图夹中使用getPosition()
,它将返回位置
更新
AwesomeViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
callback.onItemClick(getAdapterPosition());
}
});
mTextView = (TextView) itemView.findViewById(R.id.mTextView);
}
String[] values = {"Hello","World"};
RecyclerAdapter recyclerAdapter = new RecyclerAdapter(values, new RecyclerAdapter.ClickCallback() {
@Override
public void onItemClick(int position) {
// Do anything with the item position
}
});
getPosition()
现在已被弃用,并替换为getAdapterPosition()
更新2020
getAdapterPosition()
现在已被弃用,并替换为getAbsoluteAdapterPosition()
或getBindingAdapterPosition()
Kotlin代码:
覆盖BindViewHolder(holder:MyHolder,position:Int){
//-在此位置从数据集中获取元素
val item=myDataset.get(holder.absoluteAdapterPosition)
}
补充@tyczj答案:
通用适配器Pseido代码:
public abstract class GenericRecycleAdapter<T, K extends RecyclerView.ViewHolder> extends RecyclerView.Adapter{
private List<T> mList;
//default implementation code
public abstract int getLayout();
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(getLayout(), parent, false);
return getCustomHolder(v);
}
public Holders.TextImageHolder getCustomHolder(View v) {
return new Holders.TextImageHolder(v){
@Override
public void onClick(View v) {
onItem(mList.get(this.getAdapterPosition()));
}
};
}
abstract void onItem(T t);
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
onSet(mList.get(position), (K) holder);
}
public abstract void onSet(T item, K holder);
}
适配器用法:
public class CategoriesAdapter extends GenericRecycleAdapter<Category, Holders.TextImageHolder> {
public CategoriesAdapter(List<Category> list, Context context) {
super(list, context);
}
@Override
void onItem(Category category) {
}
@Override
public int getLayout() {
return R.layout.categories_row;
}
@Override
public void onSet(Category item, Holders.TextImageHolder holder) {
}
}
public class CategoriesAdapter扩展了GenericRecycleAdapter{
公共类别适配器(列表、上下文){
超级(列表、上下文);
}
@凌驾
虚无主义(类别){
}
@凌驾
公共int getLayout(){
返回R.layout.categories\u行;
}
@凌驾
公共无效开始(类别项,holder.TextImageHolder){
}
}
另一种方法-使用View类的setTag()和getTag()方法
在适配器的onBindViewHolder方法中使用setTag()
@Override
public void onBindViewHolder(myViewHolder viewHolder, int position) {
viewHolder.mCardView.setTag(position);
}
其中,在myViewHolder类中定义了mCardView
private class myViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public View mCardView;
public myViewHolder(View view) {
super(view);
mCardView = (CardView) view.findViewById(R.id.card_view);
mCardView.setOnClickListener(this);
}
}
在OnClickListener实现中使用getTag()
@Override
public void onClick(View view) {
int position = (int) view.getTag();
//display toast with position of cardview in recyclerview list upon click
Toast.makeText(view.getContext(),Integer.toString(position),Toast.LENGTH_SHORT).show();
}
有关更多详细信息,请参见我是通过这种方式解决的
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
FrameLayout root;
public ViewHolder(View itemView) {
super(itemView);
root = (FrameLayout) itemView.findViewById(R.id.root);
root.setOnClickListener(this);
}
@Override
public void onClick(View v) {
LogUtils.errorLog("POS_CLICKED: ",""+getAdapterPosition());
}
}
class MyOnClickListener implements View.OnClickListener {
@Override
public void onClick(View v) {
int itemPosition = mRecyclerView.getChildAdapterPosition(v);
myResult = results.get(itemPosition);
}
}
和在适配器中
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_wifi, parent, false);
v.setOnClickListener(new MyOnClickListener());
ViewHolder vh = new ViewHolder(v);
return vh;
}
获得焦点子对象,并使用它在适配器中获得位置
mRecyclerView.getChildAdapterPosition(mRecyclerView.getFocusedChild())
我认为获得项目位置的最正确方法是
View.OnClickListener onClickListener = new View.OnClickListener() {
@Override public void onClick(View v) {
View view = v;
View parent = (View) v.getParent();
while (!(parent instanceof RecyclerView)){
view=parent;
parent = (View) parent.getParent();
}
int position = recyclerView.getChildAdapterPosition(view);
}
因为是视图,所以您并不总是单击行布局的根视图。若视图不是根视图(例如按钮),您将得到类强制转换异常。因此,首先我们需要找到视图,它是视图的直接子视图。然后,使用recyclerView.getChildAdapterPosition(视图)查找位置 就我个人而言,我发现的最简单的方法是:
在“RecycleAdapter”类(子类)内创建接口。
在构造函数中添加接口变量作为参数。
private String[] items;
private ClickCallback callback;
public RecyclerAdapter(String[] items, ClickCallback clickCallback) {
this.items = items;
this.callback = clickCallback;
}
在ViewHolder(另一个子类)中设置单击侦听器,并通过界面将“位置”传递给
AwesomeViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
callback.onItemClick(getAdapterPosition());
}
});
mTextView = (TextView) itemView.findViewById(R.id.mTextView);
}
String[] values = {"Hello","World"};
RecyclerAdapter recyclerAdapter = new RecyclerAdapter(values, new RecyclerAdapter.ClickCallback() {
@Override
public void onItemClick(int position) {
// Do anything with the item position
}
});
现在,在活动/片段中初始化回收器适配器时,只需创建一个新的“ClickCallback”(界面)
对我来说就是这样。:) 无需让您的ViewHolder实现View.OnClickListener。通过在RecyclerView的onCreateViewHolder方法中设置click侦听器,可以直接获得单击的位置。以下是代码示例:
public class ItemListAdapterRecycler extends RecyclerView.Adapter<ItemViewHolder>
{
private final List<Item> items;
public ItemListAdapterRecycler(List<Item> items)
{
this.items = items;
}
@Override
public ItemViewHolder onCreateViewHolder(final ViewGroup parent, int viewType)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_row, parent, false);
view.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
int currentPosition = getClickedPosition(view);
Log.d("DEBUG", "" + currentPosition);
}
});
return new ItemViewHolder(view);
}
@Override
public void onBindViewHolder(ItemViewHolder itemViewHolder, int position)
{
...
}
@Override
public int getItemCount()
{
return items.size();
}
private int getClickedPosition(View clickedView)
{
RecyclerView recyclerView = (RecyclerView) clickedView.getParent();
ItemViewHolder currentViewHolder = (ItemViewHolder) recyclerView.getChildViewHolder(clickedView);
return currentViewHolder.getAdapterPosition();
}
}
公共类ItemListAdapterRecycler扩展了RecyclerView.Adapter
{
私人最终清单项目;
public ItemListAdapterRecycler(列表项)
{
这个项目=项目;
}
@凌驾
public ItemViewHolder onCreateViewHolder(最终视图组父级,int-viewType)
{
View=LayoutFlater.from(parent.getContext()).flate(R.layout.item_行,parent,false);
view.setOnClickListener(新的view.OnClickListener()
{
@凌驾
公共void onClick(视图)
{
int currentPosition=getClickedPosition(视图);
Log.d(“调试”,“当前位置”);
}
});
返回新的ItemViewHolder(视图);
}
@凌驾
BindViewHolder上的公共无效(ItemViewHolder ItemViewHolder,int位置)
{
...
}
@凌驾
public int getItemCount()
{
返回items.size();
}
私有int getClickedPosition(视图clickedView)
{
RecycleView RecycleView=(RecycleView)clickedView.getParent();
ItemViewHolder currentViewHolder=(ItemViewHolder)recyclerView.getChildViewHolder(clickedView);
返回currentViewHolder.getAdapterPosition();
}
}
1。创建类名RecyclerTouchListener.java
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
public class RecyclerTouchListener implements RecyclerView.OnItemTouchListener
{
private GestureDetector gestureDetector;
private ClickListener clickListener;
public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final ClickListener clickListener) {
this.clickListener = clickListener;
gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
@Override
public void onLongPress(MotionEvent e) {
View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null) {
clickListener.onLongClick(child, recyclerView.getChildAdapterPosition(child));
}
}
});
}
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View child = rv.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
clickListener.onClick(child, rv.getChildAdapterPosition(child));
}
return false;
}
@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
public interface ClickListener {
void onClick(View view, int position);
void onLongClick(View view, int position);
}
}
2。致电RecyclerTouchListener
recycleView.addOnItemTouchListener(new RecyclerTouchListener(this, recycleView,
new RecyclerTouchListener.ClickListener() {
@Override
public void onClick(View view, int position) {
Toast.makeText(MainActivity.this,Integer.toString(position),Toast.LENGTH_SHORT).show();
}
@Override
public void onLongClick(View view, int position) {
}
}));
onBindViewHolder()是为每个项目调用的,当您可以在ViewHolder构造函数中调用一次时,在onBindVieHolder()中设置click侦听器是不必要的重复选项
public class MyViewHolder extends RecyclerView.ViewHolder
implements View.OnClickListener{
public final TextView textView;
public MyViewHolder(View view){
textView = (TextView) view.findViewById(R.id.text_view);
view.setOnClickListener(this);
// getAdapterPosition() retrieves the position here.
}
@Override
public void onClick(View v){
// Clicked on item
Toast.makeText(mContext, "Clicked on position: " + getAdapterPosition(), Toast.LENGTH_SHORT).show();
}
}
简单地说,在使用数据绑定时,在ViewHolder
上,您需要从项目的单击侦听器内部了解RecyclerView单击位置:
科特林
val recyclerView = view.parent as RecyclerView
val position = recyclerView.getChildAdapterPosition(view)
你能展示一些代码吗?如果taskViewHolder没有setOnClickListener方法,我如何执行此操作?您可以在中使用viewholder中的视图there@tyczj不,更好的方法是在ViewHolder中设置侦听器,观众知道他们自己的观点positions@pskink如果不将位置传递给构造函数,您如何知道位置?@tyczj ViewHolder.getPosition(),顺便说一句,当您创建一个不知道位置的ViewHolder时,位置是在onbindviewholder中设置的
@Override
public void onClick(View v) {
int pos = getAdapterPosition();
}
val recyclerView = view.parent as RecyclerView
val position = recyclerView.getChildAdapterPosition(view)