RecyclerView Item Edit 复用问题

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RecyclerView Item Edit 复用问题

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RecyclerView 列表控件 传承了ListView GridView Item 复用的机制 在滑动屏幕时更新数据 共用一套或者特定的几套View Holder展示数据 。。。

ViewHolder 加载数据

• Item 加载List 展示数据
• Item 中包含交互输入的View List数据交互
• Item 中包含交互输入的View List数据没有交互

如果Item 交互控件 没有和List数据交互（保存/清除）在复用的机制上就会出现重复 错乱的问题，回想 ListView GridView 的Adapter ViewHolder 上都绑定了Tag 将数据直接定位到展示的ViewHolder。。。

EditText 输入信息的监听

 /**
 * Adds a TextWatcher to the list of those whose methods are called
 * whenever this TextView's text changes.
 * <p>
 * In 1.0, the {@link TextWatcher#afterTextChanged} method was erroneously
 * not called after {@link #setText} calls.  Now, doing {@link #setText}
 * if there are any text changed listeners forces the buffer type to
 * Editable if it would not otherwise be and does call this method.
 */
public void addTextChangedListener(TextWatcher watcher) {
    if (mListeners == null) {
        mListeners = new ArrayList<TextWatcher>();
    }

    mListeners.add(watcher);
}

• 添加 TextWatcher

    /**
     * Removes the specified TextWatcher from the list of those whose
     * methods are called
     * whenever this TextView's text changes.
     */
    public void removeTextChangedListener(TextWatcher watcher) {
        if (mListeners != null) {
            int i = mListeners.indexOf(watcher);
  
            if (i >= 0) {
                mListeners.remove(i);
            }
        }
    }
  

• 删除 TextWatcher

解决方案：

• 在绑定数据的时候 先检测 view.getTag() 是否存在TextWatcher 如果存在 删除之前的绑定

• 添加之前存储的Index ->ViewHolder 下的数据

• 添加 新的监听 添加新的Tag view.setTag(textWatcher)

    if (((TwoViewHolder) holder).mEditQuestion.getTag() instanceof EditInputCallBack) {
                ((TwoViewHolder) holder).mEditQuestion.removeTextChangedListener((TextWatcher)
                        ((TwoViewHolder) holder).mEditQuestion.getTag());
            }
  
            if (editInputModel != null && editInputModel.size() > 0) {
                String str = editInputModel.get(index);
                ((TwoViewHolder) holder).mTxtQuestion.setText(questionContent != null ? position + "、 " + questionContent : "");
                ((TwoViewHolder) holder).mEditQuestion.setText(str != null ? str : "");
            } else {
                ((TwoViewHolder) holder).mTxtQuestion.setText(questionContent != null ? position + "、 " + questionContent : "");
                ((TwoViewHolder) holder).mEditQuestion.setText(answer != null ? answer : "");
            }
  
     	
            ((TwoViewHolder) holder).mEditQuestion.addTextChangedListener(callBack);
            ((TwoViewHolder) holder).mEditQuestion.setTag(callBack);