在 RecyclerView 中保存 EditText 内容

Question

我有 EditText 的列表项，我不知道会有多少项。当我在 EditText 中输入一些文本然后向下滚动 RecyclerView 时出现问题，再次向上滚动后我的第一个 EditText.[=19 中没有文本=]

我想知道我应该在什么地方编写代码，以便在用户输入或完成输入时（我想用 TextWatcher 来做到这一点）在 EditText 文本中被保存到文件中（我将其保存在外部存储中的 .txt 文件中）

我是否应该在 activity 的 onCreate 方法或适配器 class 或其他地方这样做？

这是一些代码

主要Activity代码

 public class MainActivity extends Activity {

    RecyclerView mRecyclerView;
    MyAdapter mAdapter;
    String[] mDataSet= new String[20];
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // generating text for editText Views
        for (int i = 0; i<=19; i++){
        mDataSet[i]= "EditText n: "+i;

    }
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        mAdapter = new MyAdapter(mDataSet);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
        mRecyclerView.setAdapter(mAdapter);
        mRecyclerView.setHasFixedSize(true);
    }

我的适配器代码

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

private String[] mDataset;


public static class ViewHolder extends RecyclerView.ViewHolder {
    // each data item is just a string in this case
    public EditText mEditText;

    public ViewHolder(View v) {
        super(v);

        mEditText = (EditText) v.findViewById(R.id.list_item_edittext);
    }
}

public MyAdapter(String[] myDataset) {
    mDataset = myDataset;
}

@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                 int viewType) {

    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.list_item, parent, false);

    ViewHolder vh = new ViewHolder(v);
    return vh;
}

@Override
public void onBindViewHolder(ViewHolder holder,  final int position) {
    holder.mEditText.setText(mDataset[position]);

    //without this addtextChangedListener my code works fine ovbiusly
    // not saving the content of the edit Text when scrolled
    // If i add this code then when i scroll all textView that go of screen
    // and than come back in have messed up content
    holder.mEditText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start,
                                  int before, int count) {
           //setting data to array, when changed
           // this is a semplified example in the actual app i save the text
           // in  a .txt in the external storage
           mDataset[position] = s.toString();
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start,
                                      int count, int after) {

        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });

}

@Override
public int getItemCount() {
    return mDataset.length;
}

没有这个 "addtextChangedListener" 我的代码工作正常，显然在滚动时不保存编辑文本的内容。如果我添加此代码，当我滚动所有离开屏幕然后返回的 editText 视图时，内容会变得一团糟。

Answer 1

我对 RecyclerView 对象不太熟悉，但我对 ListView 也有同样的问题。对于那些，我通常会创建一个临时的 class 来表示插入到我的视图中的值（它与 EditTexts、Checkboxes、RadioButtons...一起使用）并通过它们获取更新的数据。然后，我创建了一个由所述容器对象组成的自定义 ArrayAdapter，在每个 getView() 回调中检索要放入 edittexts 的值，并实现一个 textwatcher 以使这些对象保持最新。同样，我不记得 RecyclerViews 是如何工作的，但如果它们涉及适配器，这可能是您尝试的一个很好的技巧。

Answer 2

创建一个包含适配器数据大小的字符串数组。

例如：String[] texts = new String[dataSize];

在适配器内的 onBindViewHolder 方法上，将 TextChangedListener 添加到 Textview。

例如：-

@Override
    public void onBindViewHolder(Viewholder holder, int position) {

//binding data from array 
   holder.yourEditText.setText(texts [position]);
   holder.yourEditText.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start,
                    int before, int count) {
                //setting data to array, when changed
                texts [position] = s.toString();
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start,
                    int count, int after) {
                //blank
            }

            @Override
            public void afterTextChanged(Editable s) {
                //blank
            }
        });


}

Answer 3

您的解决方案的主要问题是在 onBindViewHolder 中分配和指定 TextWatcher，这是一项昂贵的操作，会在快速滚动期间引入滞后，而且似乎还会干扰确定要在 mAdapter 中更新的位置。

在onCreateViewHolder 中进行所有操作是更可取的选择。这是完整的测试工作解决方案：

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

    private String[] mDataset;

    public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_edittext, parent, false);
        // pass MyCustomEditTextListener to viewholder in onCreateViewHolder
        // so that we don't have to do this expensive allocation in onBindViewHolder
        ViewHolder vh = new ViewHolder(v, new MyCustomEditTextListener());

        return vh;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        // update MyCustomEditTextListener every time we bind a new item
        // so that it knows what item in mDataset to update
        holder.myCustomEditTextListener.updatePosition(holder.getAdapterPosition());
        holder.mEditText.setText(mDataset[holder.getAdapterPosition()]);
    }

    @Override
    public int getItemCount() {
        return mDataset.length;
    }


    public static class ViewHolder extends RecyclerView.ViewHolder {
        // each data item is just a string in this case
        public EditText mEditText;
        public MyCustomEditTextListener myCustomEditTextListener;

        public ViewHolder(View v, MyCustomEditTextListener myCustomEditTextListener) {
            super(v);

            this.mEditText = (EditText) v.findViewById(R.id.editText);
            this.myCustomEditTextListener = myCustomEditTextListener;
            this.mEditText.addTextChangedListener(myCustomEditTextListener);
        }
    }

    // we make TextWatcher to be aware of the position it currently works with
    // this way, once a new item is attached in onBindViewHolder, it will
    // update current position MyCustomEditTextListener, reference to which is kept by ViewHolder
    private class MyCustomEditTextListener implements TextWatcher {
        private int position;

        public void updatePosition(int position) {
            this.position = position;
        }

        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
            // no op
        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
            mDataset[position] = charSequence.toString();
        }

        @Override
        public void afterTextChanged(Editable editable) {
            // no op
        }
    }
}

Answer 4

你好@mikwee 确保你在下面的方法中添加文本更改监听器而不是将它添加到 onBindViewHolder()。

public ViewHolder(View v) {
        super(v);

  yourEditText.addTextChangedListener(new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start,
                int before, int count) {
            //setting data to array, when changed
            texts [position] = s.toString();
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start,
                int count, int after) {

        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });


}

Answer 5

我会创建一个接口并传递当前适配器位置来处理文本更改事件

    public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

    private String[] mDataset;

    public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_edittext, parent, false);
        ViewHolder vh = new ViewHolder(v, new ViewHolder.ITextWatcher() {
            @Override
            public void beforeTextChanged(int position, CharSequence s, int start, int count, int after) {
                // do something
            }

            @Override
            public void onTextChanged(int position, CharSequence s, int start, int before, int count) {
                mDataset[position] = s.toString();
            }

            @Override
            public void afterTextChanged(int position, Editable s) {
                // do something
            }
        });

        return vh;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        holder.mEditText.setText(mDataset[position]);
    }

    @Override
    public int getItemCount() {
        return mDataset.length;
    }


    public static class ViewHolder extends RecyclerView.ViewHolder {

        public EditText mEditText;
        private ITextWatcher mTextWatcher;

        public interface ITextWatcher {
            // you can add/remove methods as you please, maybe you dont need this much
            void beforeTextChanged(int position, CharSequence s, int start, int count, int after);

            void onTextChanged(int position, CharSequence s, int start, int before, int count);

            void afterTextChanged(int position, Editable s);
        }

        public ViewHolder(View v, ITextWatcher textWatcher) {
            super(v);

            this.mEditText = (EditText) v.findViewById(R.id.editText);

            this.mTextWatcher = textWatcher;

            this.mEditText.addTextChangedListener(new TextWatcher() {
                @Override
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                    mTextWatcher.beforeTextChanged(getAdapterPosition(), s, start, count, after);
                }

                @Override
                public void onTextChanged(CharSequence s, int start, int before, int count) {
                    mTextWatcher.onTextChanged(getAdapterPosition(), s, start, before, count);
                }

                @Override
                public void afterTextChanged(Editable s) {
                    mTextWatcher.afterTextChanged(getAdapterPosition(), s);
                }
            });
        }
    }

}

Answer 6

我遇到了同样的问题，我添加了以下行，似乎已经解决了我这边的问题。

mRecyclerview.setItemViewCacheSize(mDataset.size());

希望这能解决您的问题。

Answer 7

根据我的说法，这是对@dkarmazi 的回答的更优化

public class UploadPhotoAdapter extends RecyclerView.Adapter<UploadPhotoAdapter.MyViewHolder> {
        ArrayList<Feed> feeds;
        Activity activity;
        public UploadPhotoAdapter(Activity activity, ArrayList<Feed> feeds) {
            this.feeds = feeds;
            this.activity = activity;
        }

        @Override
        public UploadPhotoAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.upload_feeds_recycler, parent, false);
            return new UploadPhotoAdapter.MyViewHolder(itemView);
        }

        @Override
        public void onBindViewHolder(final UploadPhotoAdapter.MyViewHolder holder, int position) {
            Feed feed = feeds.get(holder.getAdapterPosition());
            holder.captionEditText.setText(feed.getDescription());
            holder.captionEditText.addTextChangedListener(new TextWatcher() {
                @Override
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
                @Override
                public void onTextChanged(CharSequence s, int start, int before, int count) {
                    feeds.get(holder.getAdapterPosition()).setDescription(s.toString());
                }
                @Override
                public void afterTextChanged(Editable s) {}
            });
        }
        @Override
        public int getItemCount() {
            return feeds.size();
        }

        public class MyViewHolder extends RecyclerView.ViewHolder {
            EditText captionEditText;
            public MyViewHolder(View view) {
                super(view);
                captionEditText = (EditText) view.findViewById(R.id.captionEditText);
            }
        }

    }

Answer 8

我实施了@dkarmazi 解决方案，但它对我没有帮助。所以，我走得更远，找到了真正可行的解决方案。

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

    private String[] mDataset;

    public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                               int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_edittext, parent, false);
        // pass MyCustomEditTextListener to viewholder in onCreateViewHolder
        // so that we don't have to do this expensive allocation in onBindViewHolder
        ViewHolder vh = new ViewHolder(v, new MyCustomEditTextListener());

        return vh;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        // update MyCustomEditTextListener every time we bind a new item
        // so that it knows what item in mDataset to update
        holder.myCustomEditTextListener.updatePosition(holder.getAdapterPosition());
        holder.mEditText.setText(mDataset[holder.getAdapterPosition()]);
    }

    @Override
    public int getItemCount() {
        return mDataset.length;
    }

    @Override
    public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
        ((ViewHolder) holder).enableTextWatcher();
    }

    @Override
    public void onViewDetachedFromWindow(@NonNull RecyclerView.ViewHolder holder) {
        ((ViewHolder) holder).disableTextWatcher();
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        // each data item is just a string in this case
        public EditText mEditText;
        public MyCustomEditTextListener myCustomEditTextListener;

        public ViewHolder(View v, MyCustomEditTextListener myCustomEditTextListener) {
            super(v);

            this.mEditText = (EditText) v.findViewById(R.id.editText);
            this.myCustomEditTextListener = myCustomEditTextListener;
        }
        
        void enableTextWatcher() {
            mEditText.addTextChangedListener(myCustomEditTextListener);
        }

        void disableTextWatcher() {
            mEditText.removeTextChangedListener(myCustomEditTextListener);
        }
    }

    // we make TextWatcher to be aware of the position it currently works with
    // this way, once a new item is attached in onBindViewHolder, it will
    // update current position MyCustomEditTextListener, reference to which is kept by ViewHolder
    private class MyCustomEditTextListener implements TextWatcher {
        private int position;

        public void updatePosition(int position) {
            this.position = position;
        }

        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
            // no op
        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
            mDataset[position] = charSequence.toString();
        }

        @Override
        public void afterTextChanged(Editable editable) {
            // no op
        }
    }
}

主要问题是应用的 TextWatcher 在项目回收期间继续工作。

我试过在回收之前禁用它，但是没有任何“beforeRecycle”事件方法。所以我用了onViewDetachedFromWindow的方法，效果很好。

Answer 9

像这样重写 RecyclerView 适配器中的 onViewRecycled 方法：

@Override
public void onViewRecycled(@NonNull ViewHolder holder) {
    mDataSet[holder.getAdapterPosition()] = holder.mEditText.getText().toString();
}

Answer 10

对我来说，上述解决方案没有用。对于其中一些，侦听器没有调用，当在 onBindViewHolder 方法中调用侦听器时，似乎即使在滚动时也会调用侦听器事件。 'Text' 正在改变，所以我尝试了 key listener，它工作正常。我猜在滚动过程中没有按下任何键。

holder.ticketNo.setOnKeyListener(new View.OnKeyListener() {
                @Override
                public boolean onKey(View v, int keyCode, KeyEvent event) {
                    results.get(position).TicketNo = holder.ticketNo.getText().toString();
                    return false;
                }
            });

对我有用的代码。

Answer 11

我重写了方法 getItemViewType 为我解决了问题

override fun getItemViewType(position: Int): Int {
    return position
}

Answer 12

如果使用数据绑定，请使用双向绑定

https://medium.com/swlh/how-data-binding-helps-you-when-working-with-edittext-inside-recyclerview-543a1eb5f2cc

Answer 13

实施View.OnFocusChangeListener

@Override
public void onBindViewHolder(Viewholder holder, int position) {
        editText.setText(model.getValue());
        editText.setOnFocusChangeListener(this);
        editText.setTag(position);
}

@Override
public void onFocusChange(View v, boolean hasFocus) {
    if (v.getTag() == null)
        return;
    int position = (int) v.getTag();
    if (!hasFocus && v instanceof EditText)
        mValues.get(position).setValue(((EditText) v).getText().toString());
}

Answer 14

问题是你【添加】了一个监听器，而不是【设置】了一个监听器。所以当view被回收的时候，有的EditText会有1个以上的listener。

要解决此问题，应在回收视图时清除侦听器。

步骤 1

使用自定义 EditText 替换。

public class RecyclerViewEditText extends AppCompatEditText {

    private ArrayList<TextWatcher> mListeners = null;

    public RecyclerViewEditText(@NonNull Context context) {
        super(context);
    }

    public RecyclerViewEditText(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public RecyclerViewEditText(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public void addTextChangedListener(TextWatcher watcher)
    {
        if (mListeners == null)
        {
            mListeners = new ArrayList<>();
        }
        mListeners.add(watcher);

        super.addTextChangedListener(watcher);
    }

    @Override
    public void removeTextChangedListener(TextWatcher watcher)
    {
        if (mListeners != null)
        {
            int i = mListeners.indexOf(watcher);
            if (i >= 0)
            {
                mListeners.remove(i);
            }
        }

        super.removeTextChangedListener(watcher);
    }

    public void clearTextChangedListeners()
    {
        if(mListeners != null)
        {
            for(TextWatcher watcher : mListeners)
            {
                super.removeTextChangedListener(watcher);
            }

            mListeners.clear();
            mListeners = null;
        }
    }
}

步骤 2

将 xml 中的 EditText 替换为上面的内容。

    <com.xxxxxxxx.widget.RecyclerViewEditText
        android:id="@+id/et_remark"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:background="@null"
        android:gravity="end"
        android:hint="input hint"
        android:inputType="textPersonName" />

步骤 3

回收视图时，清除适配器中的所有侦听器。

@Override
public void onViewRecycled(@NonNull ViewHolder holder) {
    holder.et_remark.clearTextChangedListeners();
    super.onViewRecycled(holder);
}

见

在 RecyclerView 中保存 EditText 内容

Saving EditText content in RecyclerView

android

android-edittext

android-recyclerview

主要Activity代码

我的适配器代码