如何更新 RecyclerView 中某个项目的特定 TextView？
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【中文标题】如何更新 RecyclerView 中某个项目的特定 TextView？【英文标题】：How to update a specific TextView of an item in the RecyclerView? 【发布时间】：2020-12-15 13:33:48 【问题描述】：当用户点击另一个项目时，我想在我的 RecyclerView 中更新之前的 TextView 项目：
例如，如果用户点击“lemanju”TextView，它会将字体颜色变为橙色，当用户点击“Lightning”TextView时，lemanju的字体颜色应该变回黑色，而Lighning的字体颜色必须变为橙色，如下所示。
lemanju being selected
Lightning being selected (How I expect it to work)
Lightning being selected (What is happening now -> not updating lemanju's font color back to black)
我在我的适配器类中尝试了以下代码来实现这个结果：
// set previous item TextColor to black.
holder.itemView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
holder.adapter.notifyItemChanged(previousSamplePosition);
// set actual item TextColor to orange.
holder.itemView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
不幸的是，当我点击 Lightning 时，我无法将 lemanju 的字体颜色改回黑色...
有谁知道如何使用 notifyItemChanged 更改特定的 TextView？或者有其他方法可以实现吗？
我的适配器类中的 onCreateViewHolder 方法，您可以在下面看到：
/**
* Sets the contents of an item at a given position in the RecyclerView.
* Called by RecyclerView to display the data at a specificed position.
*
* @param holder The view holder for that position in the RecyclerView.
* @param samplePosition The position of the item in the RecyclerView.
* <p>
*/
@Override
public void onBindViewHolder(@NonNull SampleViewHolder holder, int samplePosition)
if (sampleList != null)
Sample currentSample = sampleListFiltered.getCurrentList().get(samplePosition);
// Add the data to the view holder.
holder.sampleView.setText(currentSample.getName());
holder.bind(currentSample);
if (sampleNameSearched != null)
String sampleName = Normalizer.normalize(sampleListFiltered.getCurrentList().get(samplePosition).getName(), Normalizer.Form.NFD).replaceAll("[^\\pASCII]", "").toLowerCase();
Pattern sampleQuery = Pattern.compile(sampleNameSearched);
Matcher sampleMatcher = sampleQuery.matcher(sampleName);
SpannableStringBuilder spanString = new SpannableStringBuilder(sampleListFiltered.getCurrentList().get(samplePosition).getName());
while (sampleMatcher.find())
spanString.setSpan(new android.text.style.StyleSpan(android.graphics.Typeface.BOLD), sampleMatcher.start(), sampleMatcher.end(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
holder.sampleView.setText(spanString);
else
// This solved the problem
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
Bundle sampleBundle = new Bundle();
holder.sampleView.setOnClickListener(view ->
sampleBundle.putLong("Sample", sampleListFiltered.getCurrentList().get(samplePosition).getId());
SampleCollectorListNavigatorFragment.addScreenToStack(0);
SampleCollectorListNavigatorFragment.setLastSurveyIdAccessed(sampleListFiltered.getCurrentList().get(samplePosition).getSurveyId());
Navigation.findNavController(view).navigate(R.id.action_sampleCollectorListNavigator_to_sampleCollectorInspectSampleFragment, sampleBundle);
);
holder.sampleView.setOnLongClickListener(view ->
sampleBundle.putLong("Sample", sampleListFiltered.getCurrentList().get(samplePosition).getId());
if (sampleID == 0)
// Access the view of the previous screen
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.VISIBLE);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
else if (sampleID == sampleListFiltered.getCurrentList().get(samplePosition).getId())
if (((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).getVisibility() == View.VISIBLE)
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.GONE);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
else
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.VISIBLE);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
else if (sampleID != sampleListFiltered.getCurrentList().get(samplePosition).getId())
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
notifyItemChanged(previousSamplePosition);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.VISIBLE);
sampleID = sampleListFiltered.getCurrentList().get(samplePosition).getId();
previousSamplePosition = samplePosition;
return true;
);
更新 -> 如何解决这个问题？
为了解决我的代码中的问题，我必须在我的搜索过滤器中将字符串更新回黑色：
// This solved the problem
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
但是如果你没有和我一样的结构，或者你只是想更新回收器中之前的 TextView 项，你可以使用这部分代码：
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
notifyItemChanged(previousSamplePosition);
notifyItemChanged(previousSamplePosition) 可以解决问题。
【问题讨论】：
【参考方案1】：这是一个基本示例，下面我也添加了您的代码
你的适配器
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>
private String[] mDataset;
List<TextView> textViews = new ArrayList<>();
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class MyViewHolder extends RecyclerView.ViewHolder
// each data item is just a string in this case
public TextView textView;
public MyViewHolder(TextView v)
super(v);
textView = v.findViewById(R.id.textView);
public MyAdapter(String[] myDataset)
mDataset = myDataset;
@Override
public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent,
int viewType)
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.my_text_view, parent, false);
MyViewHolder vh = new MyViewHolder(v);
return vh;
@Override
public void onBindViewHolder(MyViewHolder holder, int position)
holder.textView.setText(mDataset[position]);
views.add(holder.textView);
@Override
public int getItemCount()
return mDataset.length;
public List<TextView> getTextViews()
return textViews;
您的活动
public class MainActivity extends AppCompatActivity
private Button changeColorButton;
private RecyclerView recyclerView;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
changeColorButton = findViewById(R.id.button);
recyclerView = findViewById(R.id.recyclerView);
MyAdapter adapter = new MyAdapter(new String[]"Hello", "world");
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
changeColorButton.setOnClickListener(new OnClickListener()
@Override
public void onClick(View view)
int length = adapter.getTextViews().size();
List<TextView> textViews = adapter.textViews;
for(int i=0; i<length; i++)
textViews.get(i).setTextColor(Color.parseColor("#bdbdbd"));
);
现在你的代码
public static class SampleViewHolder extends RecyclerView.ViewHolder
private final TextView sampleView;
/**
* Creates a new custom view holder to hold the view to display in the RecyclerView.
*
* @param sampleListView The view in which to display the data.
* @param adapter The adapter that manages the the data and views for the RecyclerView.
*/
public SampleViewHolder(View sampleListView)
super(sampleListView);
sampleView = sampleListView.findViewById(R.id.data_name);
/**
* Inflates an item view and returns a new view holder that contains it.
* Called when the RecyclerView needs a new view holder to represent an item.
*
* @param parent The view group that holds the item views.
* @param viewType Used to distinguish views, if more than one type of item view is used.
* @return a view holder.
*/
@NonNull
@Override
public SampleViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)
// Inflate an item view.
View sampleListView = inflater.inflate(R.layout.fragment_sample_collector_list_sample, parent, false);
return new SampleViewHolder(sampleListView);
/**
* Sets the contents of an item at a given position in the RecyclerView.
* Called by RecyclerView to display the data at a specificed position.
*
* @param holder The view holder for that position in the RecyclerView.
* @param samplePosition The position of the item in the RecyclerView.
* <p>
* TODO: Most important method used
*/
@Override
public void onBindViewHolder(@NonNull SampleViewHolder holder, int samplePosition)
if (sampleList != null)
// Retrieve the data for that position.
//Sample currentSample = sampleListFiltered.get(samplePosition);
Sample currentSample = sampleListFiltered.getCurrentList().get(samplePosition);
// Add the data to the view holder.
holder.sampleView.setText(currentSample.getName());
holder.bind(currentSample);
list.add(holder.sampleView);
if (sampleNameSearched != null)
String sampleName = Normalizer.normalize(sampleListFiltered.getCurrentList().get(samplePosition).getName(), Normalizer.Form.NFD).replaceAll("[^\\pASCII]", "").toLowerCase();
Pattern sampleQuery = Pattern.compile(sampleNameSearched);
Matcher sampleMatcher = sampleQuery.matcher(sampleName);
SpannableStringBuilder spanString = new SpannableStringBuilder(sampleListFiltered.getCurrentList().get(samplePosition).getName());
while (sampleMatcher.find())
spanString.setSpan(new android.text.style.StyleSpan(android.graphics.Typeface.BOLD), sampleMatcher.start(), sampleMatcher.end(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
holder.sampleView.setText(spanString);
Bundle sampleBundle = new Bundle();
holder.sampleView.setOnClickListener(view ->
sampleBundle.putLong("Sample", sampleListFiltered.getCurrentList().get(samplePosition).getId());
SampleCollectorListNavigatorFragment.addPreviousScreen(0);
SampleCollectorListNavigatorFragment.setLastSurveyIdAccessed(sampleListFiltered.getCurrentList().get(samplePosition).getSurveyId());
Navigation.findNavController(view).navigate(R.id.action_sampleCollectorListNavigator_to_sampleCollectorInspectSampleFragment, sampleBundle);
);
holder.sampleView.setOnLongClickListener(view ->
sampleBundle.putLong("Sample", sampleListFiltered.getCurrentList().get(samplePosition).getId());
// TODO: if the same button is clicked close the buttonPanel, else keep it open.
if (sampleID == 0)
// Access the view of the previous screen
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.VISIBLE);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
else if (sampleID == sampleListFiltered.getCurrentList().get(samplePosition).getId())
if (((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).getVisibility() == View.VISIBLE)
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.GONE);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
else
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.VISIBLE);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
else if (sampleID != sampleListFiltered.getCurrentList().get(samplePosition).getId())
Toast.makeText(inflater.getContext(), "list size() " + list.size(), Toast.LENGTH_SHORT).show();
// I CANNOT CHANGE THE COLOR OF THE PREVIOUS SAMPLE RIGHT HERE.
List<RecyclerView.ViewHolder> vh = getItem();
changeColor(vh,previousSamplePosition);
holder.adapter.notifyItemChanged(previousSamplePosition);
holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.PrimaryColor_1));
((Activity) inflater.getContext()).findViewById(R.id.ButtonPanel).setVisibility(View.VISIBLE);
sampleID = sampleListFiltered.getCurrentList().get(samplePosition).getId();
previousSamplePosition = samplePosition;
return true;
);
public List<RecyclerView.ViewHolder> getItem()
return list;
public void changeColor(List<RecyclerView.ViewHolder> vh, int previousSamplePosition)
for (int i = 0; i < list.size(); i++)
if(i == previousSamplePosition)
// Does not change the previous TextView.
Toast.makeText(inflater.getContext(), "i -> " + i + " previousSamplePos -> " + previousSamplePosition, Toast.LENGTH_SHORT).show();
// How can I use the vh here?
//vh.get(i).setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1));
//holder.adapter.notifyItemChanged(i);
让我知道它是否有效
【讨论】：
我的适配器中有所有这些结构，但是我应该在 changeColor 函数中添加什么来更改特定的 TextView 项颜色？我的意思是...如何更改适配器列表的特定项目？我将添加我的 CreateViewHolder，这样你就可以看到我在做什么...... TextView 文本； public ViewHolder(@NonNull View itemView) super(itemView);文本 = itemView.findViewById(R.id.theID); 公共 changeColor() text.setTextColor(Color.parseColor("#bdbdbd")); 参考这个链接看看怎么改变textVIew的颜色***.com/questions/8472349/… 是的，我已经在代码中使用了它，但是如何更新我点击的上一个项目？就像，我怎样才能更新以前的 TextView：// 这里......如何从以前的颜色更改并更新它？ holder.sampleView.setTextColor(ContextCompat.getColor(inflater.getContext(), R.color.BaseColor_1)); holder.adapter.notifyItemChanged(previousSamplePosition); 在我的回答中，看看最后的 2 个代码 sn-ps，一种存储所有元素的方法和一个改变每个元素颜色的循环。 getItem() 中的 viewHolders 返回变量是列表（您创建的 list）还是 ViewHolder 对象？以上是关于如何更新 RecyclerView 中某个项目的特定 TextView？的主要内容，如果未能解决你的问题，请参考以下文章
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