Question

我正在尝试找到如何从RecyclerView更改我的textViews适配器Activity，在我的活动中我有两个小部件，例如increment_text_size和{{1他们必须改变适配器文本视图，

为实现这一点，我在活动上创建简单的监听器来管理它们：

的活动：

decrement_text_size

点击小工具后我在适配器上使用这个监听器

的活动：

public interface IonChangeBookContentTextSize {
    void incrementTextSize();

    void decrementTextSize();
}

public static void setIonChangeBookContentTextSize(IonChangeBookContentTextSize l) {
    ionChangeBookContentTextSize = l;
}

现在在适配器中我正在使用这个监听器

@OnClick(R.id.decrement_text_size)
public void decrement_text_size(View view) {
    if (ionChangeBookContentTextSize != null) {
        ionChangeBookContentTextSize.decrementTextSize();
    }
}

@OnClick(R.id.increment_text_size)
public void increment_text_size(View view) {
    if (ionChangeBookContentTextSize != null) {
        ionChangeBookContentTextSize.incrementTextSize();
    }
}

将此侦听器实现为：

public class ShowBookContentsAdapter extends RecyclerView.Adapter<ShowBookContentsAdapter.ShowBookContentsViewHolder> {
    private List<Contents> list;
    private Context        context;
    private static final int NOTE = 1;
    public static IonChangeBottomViewVisibility ionChangeBottomViewvisibility;
    private       ShowBookContentsViewHolder    holder;
    private       View                          view;

    public ShowBookContentsAdapter(List<Contents> items, Context mContext, IonChangeBottomViewVisibility mOnChangeBottomViewVisibility) {
        list = items;
        context = mContext;
        ionChangeBottomViewvisibility = mOnChangeBottomViewVisibility;
    }

    @Override
    public ShowBookContentsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        int layout = -1;
        switch (viewType) {
            case 0:
                layout = R.layout.item_book_content_paragraph;
                break;
            case 1:
                layout = R.layout.item_book_content_heading_one;
                break;
        }

        view = LayoutInflater.from(parent.getContext()).inflate(layout, parent, false);
        holder = new ShowBookContentsViewHolder(view);

        return holder;
    }

    @Override
    public void onBindViewHolder(ShowBookContentsViewHolder holder, final int position) {
        switch (list.get(position).getContentType()) {
            case 0:
                implementingHeadingParagraphView(holder, position);
                break;
            case 1:
                implementingHeadingOneView(holder, position);
                break;
        }
    }

    private void implementingHeadingParagraphView(final ShowBookContentsViewHolder holder, final int position) {
        Utils.overrideFonts(context, holder.book_content_paragraph, PersianFontType.SHABNAM);

        holder.book_content_paragraph.setText(Html.fromHtml(list.get(position).getContent()));

        ActivityShowBookContent.setIonChangeBookContentTextSize(new ActivityShowBookContent.IonChangeBookContentTextSize() {
            @Override
            public void incrementTextSize() {
                holder.book_content_paragraph.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);
            }

            @Override
            public void decrementTextSize() {
                holder.book_content_paragraph.setTextSize(TypedValue.COMPLEX_UNIT_SP, 12);
            }
        });
    }

    @Override
    public int getItemViewType(int position) {
        return list.get(position).getContentType();
    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    public int getItemPosition(int itemId) {
        return itemPositions.get(itemId);
    }

    public class ShowBookContentsViewHolder extends RecyclerView.ViewHolder {
        @Nullable
        @BindView(R.id.book_content_paragraph)
        TextView book_content_paragraph;

        @Nullable
        @BindView(R.id.book_content_heading_one)
        TextView book_content_heading_one;

        public ShowBookContentsViewHolder(View view) {
            super(view);
            ButterKnife.bind(this, view);
        }
    }
}

在ActivityShowBookContent.setIonChangeBookContentTextSize(new ActivityShowBookContent.IonChangeBookContentTextSize() { @Override public void incrementTextSize() { holder.book_content_paragraph.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18); } @Override public void decrementTextSize() { holder.book_content_paragraph.setTextSize(TypedValue.COMPLEX_UNIT_SP, 12); } });方法工作当前位置，而不是对于recyclerview适配器上的所有行，我该如何解决这个问题？

Answer 1

您不必为此目的创建侦听器。您应该在适配器中保存名为textSize的字段。然后，随时根据您的活动设置此项。

public class ShowBookContentsAdapter extends RecyclerView.Adapter<ShowBookContentsAdapter.ShowBookContentsViewHolder> {

    private int textSize;

    // constructor etc.

    @Override
    public ShowBookContentsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_book_content_paragraph, parent, false);
        final ShowBookContentsViewHolder holder new ShowBookContentsViewHolder(view);

        return holder;
    }

    @Override
    public void onBindViewHolder(ShowBookContentsViewHolder holder, final int position) {
        implementingHeadingParagraphView(holder, position);
    }

    private void implementingHeadingParagraphView(final ShowBookContentsViewHolder holder, final int position) {
        Utils.overrideFonts(context, holder.book_content_paragraph, PersianFontType.SHABNAM);

        holder.book_content_paragraph.setTextSize(TypedValue.COMPLEX_UNIT_SP, textSize);

        holder.book_content_paragraph.setText(Html.fromHtml(list.get(position).getContent()));

    }

    public void setTextSizes(int textSize) {
        this.textSize = textSize;
        notifyDataSetChanged();
    }

    //... other adapter methods

    public class ShowBookContentsViewHolder extends RecyclerView.ViewHolder {
        @Nullable
        @BindView(R.id.book_content_paragraph)
        TextView book_content_paragraph;

        @Nullable
        @BindView(R.id.book_content_heading_one)
        TextView book_content_heading_one;

        public ShowBookContentsViewHolder(View view) {
            super(view);
            ButterKnife.bind(this, view);
        }
    }

从您的活动中调用此

showBookContentsAdapter.setTextSizes(18);

Answer 2

你必须从你的活动中调用notifydatasetchanged

1.首先，如果临时使用常量变量保存字体大小，或者在应用程序的整个生命周期中使用共享首选项

在您的活动中创建一个方法来保存字体大小

private void saveFontSize(boolean isFont){
 IS_LARGE_FONT= isFont;
 recyclerView.post(new Runnable(){
 adapter.notifyDataSetChanged();
 });
}

在适配器类中，只需检查bindholder中的值

if(IS_LARGE_FONT)
{
//set large font
}
else{
// set small font
}

Android从Activity更改RecyclerView适配器上的TextView textSize

2 个答案: