Recyclerview行项目选择颜色变化
Recyclerview row item selection color change
我可以在 navigation drawer fragment.[=19= 中更改 recyclerview 单击的行的 text 颜色和 imageview 背景]
但我的问题是点击第 4 项后，第 1 项也得到 selected.Likewise 点击我的第 5 项后，第 2 项被选中。
像这样：
我该如何解决这个问题？这样一次只能选择一项？
FragmentDrawer.java
public class FragmentDrawer extends Fragment {
private static String TAG = FragmentDrawer.class.getSimpleName();
private RecyclerView recyclerView;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private NavigationDrawerAdapter adapter;
private View containerView;
private static String[] titles = null;
private FragmentDrawerListener drawerListener;
public FragmentDrawer() {
}
public void setDrawerListener(FragmentDrawerListener listener) {
this.drawerListener = listener;
}
public static List<NavDrawerItem> getData() {
List<NavDrawerItem> data = new ArrayList<>();
int[] icons = {R.drawable.ic_home,
R.drawable.ic_upcoming,
R.drawable.ic_saved,
R.drawable.ic_wehappened,
R.drawable.ic_persons,
R.drawable.ic_music,
R.drawable.ic_parties,
R.drawable.ic_art, R.drawable.ic_network, R.drawable.ic_sports};
// preparing navigation drawer items
for (int i = 0; i < titles.length && i < icons.length; i++) {
NavDrawerItem navItem = new NavDrawerItem();
navItem.setTitle(titles[i]);
navItem.setIcon(icons[i]);
data.add(navItem);
}
return data;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// drawer labels
titles = getActivity().getResources().getStringArray(R.array.nav_drawer_labels);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflating view layout
View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);
adapter = new NavigationDrawerAdapter(getActivity(), getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
List<SimpleSectionedRecyclerViewAdapter.Section> sections =
new ArrayList<SimpleSectionedRecyclerViewAdapter.Section>();
//Sections
sections.add(new SimpleSectionedRecyclerViewAdapter.Section(5, "Categories"));
recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity(), recyclerView, new ClickListener() {
@Override
public void onClick(View view, int position) {
NavigationDrawerAdapter.selected_item = position;
recyclerView.getAdapter().notifyDataSetChanged();
drawerListener.onDrawerItemSelected(view, position);
mDrawerLayout.closeDrawer(containerView);
}
@Override
public void onLongClick(View view, int position) {
}
}));
SimpleSectionedRecyclerViewAdapter.Section[] dummy = new SimpleSectionedRecyclerViewAdapter.Section[sections.size()];
SimpleSectionedRecyclerViewAdapter mSectionedAdapter = new
SimpleSectionedRecyclerViewAdapter(getContext(), R.layout.section, R.id.section_text, adapter);
mSectionedAdapter.setSections(sections.toArray(dummy));
//Apply this adapter to the RecyclerView
recyclerView.setAdapter(mSectionedAdapter);
return layout;
}
public void setUp(int fragmentId, DrawerLayout drawerLayout, final Toolbar toolbar) {
containerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
getActivity().invalidateOptionsMenu();
}
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
getActivity().invalidateOptionsMenu();
}
@Override
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, slideOffset);
toolbar.setAlpha(1 - slideOffset / 2);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerLayout.post(new Runnable() {
@Override
public void run() {
mDrawerToggle.syncState();
}
});
}
public static interface ClickListener {
public void onClick(View view, int position);
public void onLongClick(View view, int position);
}
static 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.getChildPosition(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.getChildPosition(child));
}
return false;
}
@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
public interface FragmentDrawerListener {
public void onDrawerItemSelected(View view, int position);
}
}
NavigationDrawerAdapter.java
public class NavigationDrawerAdapter extends RecyclerView.Adapter<NavigationDrawerAdapter.MyViewHolder> {
List<NavDrawerItem> data = Collections.emptyList();
private LayoutInflater inflater;
private Context context;
public static int selected_item = 0;
public NavigationDrawerAdapter(Context context, List<NavDrawerItem> data) {
this.context = context;
inflater = LayoutInflater.from(context);
this.data = data;
}
public void delete(int position) {
data.remove(position);
notifyItemRemoved(position);
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.nav_drawer_row, parent, false);
MyViewHolder holder = new MyViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
if(position == selected_item)
{
holder.title.setTextColor(Color.parseColor("#00aaff"));
holder.imgViewIcon.setBackgroundResource(R.drawable.ic_circle);
}
NavDrawerItem current = data.get(position);
holder.title.setText(current.getTitle());
holder.imgViewIcon.setImageResource(current.getIcon());
}
@Override
public int getItemCount() {
return data.size();
}
class MyViewHolder extends RecyclerView.ViewHolder {
TextView title;
public ImageView imgViewIcon;
public MyViewHolder(View itemView) {
super(itemView);
title = (TextView) itemView.findViewById(R.id.title);
imgViewIcon = (ImageView) itemView.findViewById(R.id.item_icon);
}
}
}
编辑： SimpleSectionedRecyclerViewAdapter.java
public class SimpleSectionedRecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private final Context mContext;
private static final int SECTION_TYPE = 0;
private boolean mValid = true;
private int mSectionResourceId;
private int mTextResourceId;
private LayoutInflater mLayoutInflater;
private RecyclerView.Adapter mBaseAdapter;
private SparseArray<Section> mSections = new SparseArray<Section>();
public SimpleSectionedRecyclerViewAdapter(Context context, int sectionResourceId, int textResourceId,
RecyclerView.Adapter baseAdapter) {
mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mSectionResourceId = sectionResourceId;
mTextResourceId = textResourceId;
mBaseAdapter = baseAdapter;
mContext = context;
mBaseAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
@Override
public void onChanged() {
mValid = mBaseAdapter.getItemCount()>0;
notifyDataSetChanged();
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount) {
mValid = mBaseAdapter.getItemCount()>0;
notifyItemRangeChanged(positionStart, itemCount);
}
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
mValid = mBaseAdapter.getItemCount()>0;
notifyItemRangeInserted(positionStart, itemCount);
}
@Override
public void onItemRangeRemoved(int positionStart, int itemCount) {
mValid = mBaseAdapter.getItemCount()>0;
notifyItemRangeRemoved(positionStart, itemCount);
}
});
}
public static class SectionViewHolder extends RecyclerView.ViewHolder {
public TextView title;
public SectionViewHolder(View view,int mTextResourceid) {
super(view);
title = (TextView) view.findViewById(mTextResourceid);
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int typeView) {
if (typeView == SECTION_TYPE) {
final View view = LayoutInflater.from(mContext).inflate(mSectionResourceId, parent, false);
return new SectionViewHolder(view,mTextResourceId);
}else{
return mBaseAdapter.onCreateViewHolder(parent, typeView -1);
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder sectionViewHolder, int position) {
if (isSectionHeaderPosition(position)) {
((SectionViewHolder)sectionViewHolder).title.setText(mSections.get(position).title);
}else{
mBaseAdapter.onBindViewHolder(sectionViewHolder,sectionedPositionToPosition(position));
}
}
@Override
public int getItemViewType(int position) {
return isSectionHeaderPosition(position)
? SECTION_TYPE
: mBaseAdapter.getItemViewType(sectionedPositionToPosition(position)) +1 ;
}
public static class Section {
int firstPosition;
int sectionedPosition;
CharSequence title;
public Section(int firstPosition, CharSequence title) {
this.firstPosition = firstPosition;
this.title = title;
}
public CharSequence getTitle() {
return title;
}
}
public void setSections(Section[] sections) {
mSections.clear();
Arrays.sort(sections, new Comparator<Section>() {
@Override
public int compare(Section o, Section o1) {
return (o.firstPosition == o1.firstPosition)
? 0
: ((o.firstPosition < o1.firstPosition) ? -1 : 1);
}
});
int offset = 0; // offset positions for the headers we're adding
for (Section section : sections) {
section.sectionedPosition = section.firstPosition + offset;
mSections.append(section.sectionedPosition, section);
++offset;
}
notifyDataSetChanged();
}
public int positionToSectionedPosition(int position) {
int offset = 0;
for (int i = 0; i < mSections.size(); i++) {
if (mSections.valueAt(i).firstPosition > position) {
break;
}
++offset;
}
return position + offset;
}
public int sectionedPositionToPosition(int sectionedPosition) {
if (isSectionHeaderPosition(sectionedPosition)) {
return RecyclerView.NO_POSITION;
}
int offset = 0;
for (int i = 0; i < mSections.size(); i++) {
if (mSections.valueAt(i).sectionedPosition > sectionedPosition) {
break;
}
--offset;
}
return sectionedPosition + offset;
}
public boolean isSectionHeaderPosition(int position) {
return mSections.get(position) != null;
}
@Override
public long getItemId(int position) {
return isSectionHeaderPosition(position)
? Integer.MAX_VALUE - mSections.indexOfKey(position)
: mBaseAdapter.getItemId(sectionedPositionToPosition(position));
}
@Override
public int getItemCount() {
return (mValid ? mBaseAdapter.getItemCount() + mSections.size() : 0);
}
}
将 NavigationDrawerAdapter.java 的 onBindViewHolder 方法更改为：
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
if(position == selected_item) {
holder.title.setTextColor(Color.parseColor("#00aaff"));
holder.imgViewIcon.setBackgroundResource(R.drawable.ic_circle);
} else {
holder.title.setTextColor(Color.parseColor("#00000")); //actually you should set to the normal text color
holder.imgViewIcon.setBackgroundResource(0);
}
NavDrawerItem current = data.get(position);
holder.title.setText(current.getTitle());
holder.imgViewIcon.setImageResource(current.getIcon());
}
您可以将 class 用于 Recycler 视图 TouchListener
class RecyclerTouchListener implements RecyclerView.OnItemTouchListener{
private ClickListener clicklistener;
private GestureDetector gestureDetector;
public RecyclerTouchListener(Context context, final RecyclerView recycleView, 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=recycleView.findChildViewUnder(e.getX(),e.getY());
if(child!=null && clicklistener!=null){
clicklistener.onLongClick(child,recycleView.getChildAdapterPosition(child));
}
}
});
}
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View child=rv.findChildViewUnder(e.getX(),e.getY());
RecyclerView.ViewHolder viewHolder=rv.findContainingViewHolder(child);
if(child!=null && clicklistener!=null && gestureDetector.onTouchEvent(e)){
clicklistener.onClick(child,rv.getChildAdapterPosition(child),viewHolder);
}
return false;
}
@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
}
实现接口
public interface ClickListener{
public void onClick(View view, int position,RecyclerView.ViewHolder viewHolder);
public void onLongClick(View view, int position);
}
然后在你的 Main Activity（这里我设置了图片资源，你可以随意设置，任何东西）
创建一个名为 "selected" 的数组列表作为 Integer 并添加以下代码作为 OnClickListener
recyclerViewSchedule.addOnItemTouchListener(new RecyclerTouchListener(this,
recyclerViewSchedule, new ClickListener() {
@Override
public void onClick(View view, final int position, RecyclerView.ViewHolder v) {
//Values are passing to activity & to fragment as well
if(!selected.contains(position))
{
selected.add(position);
((ScheduleAdapter.MyHolder) v).txtImage.setBackgroundColor(getResources().getColor(R.color.colorAccent));
}else {
((ScheduleAdapter.MyHolder) v).txtImage.setBackgroundColor(getResources().getColor(R.color.colorTransparent));
selected.remove(new Integer(position));
}
Toast.makeText(ScheduleActivity.this, "Single Click on position :"+position,
Toast.LENGTH_SHORT).show();
}
Toast.makeText(ScheduleActivity.this, "Single Click on position :"+position,
Toast.LENGTH_SHORT).show();
}
@Override
public void onLongClick(View view, int position) {
Toast.makeText(ScheduleActivity.this, "Long press on position :"+position,
Toast.LENGTH_LONG).show();
}
}));
我这里指定的txtImage来自RecyclerAdapter，用你的View替换它
快乐编码:-)
Simple and Best
Inside Adapter class
int row_index=0;
inside onBindViewHOlder
holder.titleLL.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
row_index=position;
notifyDataSetChanged();
}
});
if (row_index==position) {
holder.title.setTextColor(Color.RED);
} else {
holder.title.setTextColor(Color.BLACK);
}
此类问题的大部分答案都是关于在 onBindViewHolder 中覆盖 Onclick 或实现用于在回收器视图中单击的界面。但众所周知，在滚动期间填充视图时会调用 onBindViewHolder。因此，您将多次调用 setOnClickListener，因此这不是一种有效的方法，而且实现界面也不像我得到的答案那么容易。
此处介绍了如何在回收站视图中访问选择项目并更改其背景或在选择项目时执行任何你想做的事情。
在您的 ViewHolder 构造函数中，以这种方式为 itemView（构造函数的参数）使用 setOnTouchListener
itemView.setOnTouchListener((v, event) -> {
if (event.getAction() == MotionEvent.ACTION_UP) {
if (v.getTag() == null) {
v.setTag(true);
v.setBackgroundColor(Color.parseColor("#F31807"));
}
else {
v.setBackgroundColor(Color.TRANSPARENT);
v.setTag(null);
}
}
if (event.getAction() == MotionEvent.ACTION_MOVE) {
//default color
v.setBackgroundColor(Color.TRANSPARENT);
}
return true;
});
我们使用 ACTION_UP 来检查用户是否按下了该项目，然后我们在视图的标志中保存了一个布尔值，以便我们可以按我们想要的次数按每个项目并查看颜色的变化。 ACTION_MOVE 如果阻止是为了防止在滚动回收器视图时选择项目。如果您发现选择一个项目影响了另一个项目的选择，您可以使用这个答案：
issue : RecyclerView messed up data when scrolling
最后如果你好奇为什么我们return真正的方法看这个视频就明白了。
我尝试了很多不同的方法，但最终对我有用的解决方案是
就像我第一次做的那样
binding.download.setOnClickListener {
binding.download.visibility = View.GONE
binding.saved.visibility = View.VISIBLE
}
这对我不起作用，但经过以下更改后
不要在 onBindViewHolder 中更改颜色或可见性，而是在 ViewHolder class 中创建一个函数并从 onBindViewHolder
中调用它
class ViewHolder（变量绑定：ImageRowBinding）：RecyclerView.ViewHolder（binding.root）{
fun bind(uri: Uri, mContext: Context) {
binding.download.setOnClickListener {
binding.download.visibility = View.GONE
binding.saved.visibility = View.VISIBLE
}
}
}
并像这样从 onBindViewHolder 调用此绑定方法
holder.bind(items[position].uri, mContext)
最适合我
我可以在 navigation drawer fragment.[=19= 中更改 recyclerview 单击的行的 text 颜色和 imageview 背景]
但我的问题是点击第 4 项后，第 1 项也得到 selected.Likewise 点击我的第 5 项后，第 2 项被选中。
像这样：
我该如何解决这个问题？这样一次只能选择一项？
FragmentDrawer.java
public class FragmentDrawer extends Fragment {
private static String TAG = FragmentDrawer.class.getSimpleName();
private RecyclerView recyclerView;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private NavigationDrawerAdapter adapter;
private View containerView;
private static String[] titles = null;
private FragmentDrawerListener drawerListener;
public FragmentDrawer() {
}
public void setDrawerListener(FragmentDrawerListener listener) {
this.drawerListener = listener;
}
public static List<NavDrawerItem> getData() {
List<NavDrawerItem> data = new ArrayList<>();
int[] icons = {R.drawable.ic_home,
R.drawable.ic_upcoming,
R.drawable.ic_saved,
R.drawable.ic_wehappened,
R.drawable.ic_persons,
R.drawable.ic_music,
R.drawable.ic_parties,
R.drawable.ic_art, R.drawable.ic_network, R.drawable.ic_sports};
// preparing navigation drawer items
for (int i = 0; i < titles.length && i < icons.length; i++) {
NavDrawerItem navItem = new NavDrawerItem();
navItem.setTitle(titles[i]);
navItem.setIcon(icons[i]);
data.add(navItem);
}
return data;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// drawer labels
titles = getActivity().getResources().getStringArray(R.array.nav_drawer_labels);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflating view layout
View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);
adapter = new NavigationDrawerAdapter(getActivity(), getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
List<SimpleSectionedRecyclerViewAdapter.Section> sections =
new ArrayList<SimpleSectionedRecyclerViewAdapter.Section>();
//Sections
sections.add(new SimpleSectionedRecyclerViewAdapter.Section(5, "Categories"));
recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity(), recyclerView, new ClickListener() {
@Override
public void onClick(View view, int position) {
NavigationDrawerAdapter.selected_item = position;
recyclerView.getAdapter().notifyDataSetChanged();
drawerListener.onDrawerItemSelected(view, position);
mDrawerLayout.closeDrawer(containerView);
}
@Override
public void onLongClick(View view, int position) {
}
}));
SimpleSectionedRecyclerViewAdapter.Section[] dummy = new SimpleSectionedRecyclerViewAdapter.Section[sections.size()];
SimpleSectionedRecyclerViewAdapter mSectionedAdapter = new
SimpleSectionedRecyclerViewAdapter(getContext(), R.layout.section, R.id.section_text, adapter);
mSectionedAdapter.setSections(sections.toArray(dummy));
//Apply this adapter to the RecyclerView
recyclerView.setAdapter(mSectionedAdapter);
return layout;
}
public void setUp(int fragmentId, DrawerLayout drawerLayout, final Toolbar toolbar) {
containerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
getActivity().invalidateOptionsMenu();
}
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
getActivity().invalidateOptionsMenu();
}
@Override
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, slideOffset);
toolbar.setAlpha(1 - slideOffset / 2);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerLayout.post(new Runnable() {
@Override
public void run() {
mDrawerToggle.syncState();
}
});
}
public static interface ClickListener {
public void onClick(View view, int position);
public void onLongClick(View view, int position);
}
static 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.getChildPosition(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.getChildPosition(child));
}
return false;
}
@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
public interface FragmentDrawerListener {
public void onDrawerItemSelected(View view, int position);
}
}
NavigationDrawerAdapter.java
public class NavigationDrawerAdapter extends RecyclerView.Adapter<NavigationDrawerAdapter.MyViewHolder> {
List<NavDrawerItem> data = Collections.emptyList();
private LayoutInflater inflater;
private Context context;
public static int selected_item = 0;
public NavigationDrawerAdapter(Context context, List<NavDrawerItem> data) {
this.context = context;
inflater = LayoutInflater.from(context);
this.data = data;
}
public void delete(int position) {
data.remove(position);
notifyItemRemoved(position);
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.nav_drawer_row, parent, false);
MyViewHolder holder = new MyViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
if(position == selected_item)
{
holder.title.setTextColor(Color.parseColor("#00aaff"));
holder.imgViewIcon.setBackgroundResource(R.drawable.ic_circle);
}
NavDrawerItem current = data.get(position);
holder.title.setText(current.getTitle());
holder.imgViewIcon.setImageResource(current.getIcon());
}
@Override
public int getItemCount() {
return data.size();
}
class MyViewHolder extends RecyclerView.ViewHolder {
TextView title;
public ImageView imgViewIcon;
public MyViewHolder(View itemView) {
super(itemView);
title = (TextView) itemView.findViewById(R.id.title);
imgViewIcon = (ImageView) itemView.findViewById(R.id.item_icon);
}
}
}
编辑： SimpleSectionedRecyclerViewAdapter.java
public class SimpleSectionedRecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private final Context mContext;
private static final int SECTION_TYPE = 0;
private boolean mValid = true;
private int mSectionResourceId;
private int mTextResourceId;
private LayoutInflater mLayoutInflater;
private RecyclerView.Adapter mBaseAdapter;
private SparseArray<Section> mSections = new SparseArray<Section>();
public SimpleSectionedRecyclerViewAdapter(Context context, int sectionResourceId, int textResourceId,
RecyclerView.Adapter baseAdapter) {
mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mSectionResourceId = sectionResourceId;
mTextResourceId = textResourceId;
mBaseAdapter = baseAdapter;
mContext = context;
mBaseAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
@Override
public void onChanged() {
mValid = mBaseAdapter.getItemCount()>0;
notifyDataSetChanged();
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount) {
mValid = mBaseAdapter.getItemCount()>0;
notifyItemRangeChanged(positionStart, itemCount);
}
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
mValid = mBaseAdapter.getItemCount()>0;
notifyItemRangeInserted(positionStart, itemCount);
}
@Override
public void onItemRangeRemoved(int positionStart, int itemCount) {
mValid = mBaseAdapter.getItemCount()>0;
notifyItemRangeRemoved(positionStart, itemCount);
}
});
}
public static class SectionViewHolder extends RecyclerView.ViewHolder {
public TextView title;
public SectionViewHolder(View view,int mTextResourceid) {
super(view);
title = (TextView) view.findViewById(mTextResourceid);
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int typeView) {
if (typeView == SECTION_TYPE) {
final View view = LayoutInflater.from(mContext).inflate(mSectionResourceId, parent, false);
return new SectionViewHolder(view,mTextResourceId);
}else{
return mBaseAdapter.onCreateViewHolder(parent, typeView -1);
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder sectionViewHolder, int position) {
if (isSectionHeaderPosition(position)) {
((SectionViewHolder)sectionViewHolder).title.setText(mSections.get(position).title);
}else{
mBaseAdapter.onBindViewHolder(sectionViewHolder,sectionedPositionToPosition(position));
}
}
@Override
public int getItemViewType(int position) {
return isSectionHeaderPosition(position)
? SECTION_TYPE
: mBaseAdapter.getItemViewType(sectionedPositionToPosition(position)) +1 ;
}
public static class Section {
int firstPosition;
int sectionedPosition;
CharSequence title;
public Section(int firstPosition, CharSequence title) {
this.firstPosition = firstPosition;
this.title = title;
}
public CharSequence getTitle() {
return title;
}
}
public void setSections(Section[] sections) {
mSections.clear();
Arrays.sort(sections, new Comparator<Section>() {
@Override
public int compare(Section o, Section o1) {
return (o.firstPosition == o1.firstPosition)
? 0
: ((o.firstPosition < o1.firstPosition) ? -1 : 1);
}
});
int offset = 0; // offset positions for the headers we're adding
for (Section section : sections) {
section.sectionedPosition = section.firstPosition + offset;
mSections.append(section.sectionedPosition, section);
++offset;
}
notifyDataSetChanged();
}
public int positionToSectionedPosition(int position) {
int offset = 0;
for (int i = 0; i < mSections.size(); i++) {
if (mSections.valueAt(i).firstPosition > position) {
break;
}
++offset;
}
return position + offset;
}
public int sectionedPositionToPosition(int sectionedPosition) {
if (isSectionHeaderPosition(sectionedPosition)) {
return RecyclerView.NO_POSITION;
}
int offset = 0;
for (int i = 0; i < mSections.size(); i++) {
if (mSections.valueAt(i).sectionedPosition > sectionedPosition) {
break;
}
--offset;
}
return sectionedPosition + offset;
}
public boolean isSectionHeaderPosition(int position) {
return mSections.get(position) != null;
}
@Override
public long getItemId(int position) {
return isSectionHeaderPosition(position)
? Integer.MAX_VALUE - mSections.indexOfKey(position)
: mBaseAdapter.getItemId(sectionedPositionToPosition(position));
}
@Override
public int getItemCount() {
return (mValid ? mBaseAdapter.getItemCount() + mSections.size() : 0);
}
}
将 NavigationDrawerAdapter.java 的 onBindViewHolder 方法更改为：
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
if(position == selected_item) {
holder.title.setTextColor(Color.parseColor("#00aaff"));
holder.imgViewIcon.setBackgroundResource(R.drawable.ic_circle);
} else {
holder.title.setTextColor(Color.parseColor("#00000")); //actually you should set to the normal text color
holder.imgViewIcon.setBackgroundResource(0);
}
NavDrawerItem current = data.get(position);
holder.title.setText(current.getTitle());
holder.imgViewIcon.setImageResource(current.getIcon());
}
您可以将 class 用于 Recycler 视图 TouchListener
class RecyclerTouchListener implements RecyclerView.OnItemTouchListener{
private ClickListener clicklistener;
private GestureDetector gestureDetector;
public RecyclerTouchListener(Context context, final RecyclerView recycleView, 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=recycleView.findChildViewUnder(e.getX(),e.getY());
if(child!=null && clicklistener!=null){
clicklistener.onLongClick(child,recycleView.getChildAdapterPosition(child));
}
}
});
}
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View child=rv.findChildViewUnder(e.getX(),e.getY());
RecyclerView.ViewHolder viewHolder=rv.findContainingViewHolder(child);
if(child!=null && clicklistener!=null && gestureDetector.onTouchEvent(e)){
clicklistener.onClick(child,rv.getChildAdapterPosition(child),viewHolder);
}
return false;
}
@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
}
实现接口
public interface ClickListener{
public void onClick(View view, int position,RecyclerView.ViewHolder viewHolder);
public void onLongClick(View view, int position);
}
然后在你的 Main Activity（这里我设置了图片资源，你可以随意设置，任何东西）
创建一个名为 "selected" 的数组列表作为 Integer 并添加以下代码作为 OnClickListener
recyclerViewSchedule.addOnItemTouchListener(new RecyclerTouchListener(this,
recyclerViewSchedule, new ClickListener() {
@Override
public void onClick(View view, final int position, RecyclerView.ViewHolder v) {
//Values are passing to activity & to fragment as well
if(!selected.contains(position))
{
selected.add(position);
((ScheduleAdapter.MyHolder) v).txtImage.setBackgroundColor(getResources().getColor(R.color.colorAccent));
}else {
((ScheduleAdapter.MyHolder) v).txtImage.setBackgroundColor(getResources().getColor(R.color.colorTransparent));
selected.remove(new Integer(position));
}
Toast.makeText(ScheduleActivity.this, "Single Click on position :"+position,
Toast.LENGTH_SHORT).show();
}
Toast.makeText(ScheduleActivity.this, "Single Click on position :"+position,
Toast.LENGTH_SHORT).show();
}
@Override
public void onLongClick(View view, int position) {
Toast.makeText(ScheduleActivity.this, "Long press on position :"+position,
Toast.LENGTH_LONG).show();
}
}));
我这里指定的txtImage来自RecyclerAdapter，用你的View替换它
快乐编码:-)
Simple and Best
Inside Adapter class
int row_index=0;
inside onBindViewHOlder
holder.titleLL.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
row_index=position;
notifyDataSetChanged();
}
});
if (row_index==position) {
holder.title.setTextColor(Color.RED);
} else {
holder.title.setTextColor(Color.BLACK);
}
此类问题的大部分答案都是关于在 onBindViewHolder 中覆盖 Onclick 或实现用于在回收器视图中单击的界面。但众所周知，在滚动期间填充视图时会调用 onBindViewHolder。因此，您将多次调用 setOnClickListener，因此这不是一种有效的方法，而且实现界面也不像我得到的答案那么容易。
此处介绍了如何在回收站视图中访问选择项目并更改其背景或在选择项目时执行任何你想做的事情。
在您的 ViewHolder 构造函数中，以这种方式为 itemView（构造函数的参数）使用 setOnTouchListener
itemView.setOnTouchListener((v, event) -> {
if (event.getAction() == MotionEvent.ACTION_UP) {
if (v.getTag() == null) {
v.setTag(true);
v.setBackgroundColor(Color.parseColor("#F31807"));
}
else {
v.setBackgroundColor(Color.TRANSPARENT);
v.setTag(null);
}
}
if (event.getAction() == MotionEvent.ACTION_MOVE) {
//default color
v.setBackgroundColor(Color.TRANSPARENT);
}
return true;
});
我们使用 ACTION_UP 来检查用户是否按下了该项目，然后我们在视图的标志中保存了一个布尔值，以便我们可以按我们想要的次数按每个项目并查看颜色的变化。 ACTION_MOVE 如果阻止是为了防止在滚动回收器视图时选择项目。如果您发现选择一个项目影响了另一个项目的选择，您可以使用这个答案：
issue : RecyclerView messed up data when scrolling
最后如果你好奇为什么我们return真正的方法看这个视频就明白了。
我尝试了很多不同的方法，但最终对我有用的解决方案是
就像我第一次做的那样
binding.download.setOnClickListener {
binding.download.visibility = View.GONE
binding.saved.visibility = View.VISIBLE
}
这对我不起作用，但经过以下更改后
不要在 onBindViewHolder 中更改颜色或可见性，而是在 ViewHolder class 中创建一个函数并从 onBindViewHolder
中调用它class ViewHolder（变量绑定：ImageRowBinding）：RecyclerView.ViewHolder（binding.root）{
fun bind(uri: Uri, mContext: Context) { binding.download.setOnClickListener { binding.download.visibility = View.GONE binding.saved.visibility = View.VISIBLE } }}
并像这样从 onBindViewHolder 调用此绑定方法
holder.bind(items[position].uri, mContext)
最适合我