Saving the values entered into EditTexts of a RecyclerView

问题

I have a RecyclerView where each row also has an EditText that allows the user to enter a value.

However when the user rotates the screen the values reset to their default blank values.

So I wanted to save the values in a List or Map so I can refill the list on restore.

However I don't know how to "iterate over the current list" and grab the EditTexts and extract the values.

回答1:

If you take for example the following RecyclerView.Adapter implementation, you'll notice a few things. The List containing the data is static meaning it will not be reset on orientation changes. We are adding a TextWatcher to the EditText to allow us to update the values when they are modified, and also we are keeping track of the position by adding a tag to the view. Note that this is my particular approach, there are many ways of solving this.

Demo

Adapter

public class SampleAdapter extends RecyclerView.Adapter{
    private static List<String> mEditTextValues = new ArrayList<>();

    public SampleAdapter(){
        //Mocking content for the editText
        for(int i=1;i<=10;i++){
            mEditTextValues.add("I'm editText number "+i);
        }
        notifyDataSetChanged();
    }
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new CustomViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.edittext,parent,false));
    }
    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        CustomViewHolder viewHolder = ((CustomViewHolder)holder);
        viewHolder.mEditText.setTag(position);
        viewHolder.mEditText.setText(mEditTextValues.get(position));
    }
    @Override
    public int getItemCount() {
        return mEditTextValues.size();
    }

    public class CustomViewHolder extends RecyclerView.ViewHolder{
        private EditText mEditText;
        public CustomViewHolder(View itemView) {
            super(itemView);
            mEditText = (EditText)itemView.findViewById(R.id.editText);
            mEditText.addTextChangedListener(new TextWatcher() {
                public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {}
                public void afterTextChanged(Editable editable) {}
                public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                    if(mEditText.getTag()!=null){
                        mEditTextValues.set((int)mEditText.getTag(),charSequence.toString());
                    }
                }
            });
        }
    }
}

(gif may look like it's being reset, since it's in a loop, it's not)

来源：https://stackoverflow.com/questions/36872909/saving-the-values-entered-into-edittexts-of-a-recyclerview