java - 如何在 RecyclerView 中修改 Layout 宽度

Question

我正在努力使用 RecyclerView 和具有一些监听器的布局。

代码是这样的

• ViewHolder

   public static class ViewHolder extends RecyclerView.ViewHolder {
  
      public TextView tickerSymbol;
      public TextView companyName;
      public View highlightBuy;
      public LinearLayout categoryImage;
      public LayoutParams categoryLayoutParams;
      public LinearLayout arrowImage;
      public ImageView categoryIconSeparator;
      public ImageView arrowSeparator;
      public ImageView arrowIcon;
      public RelativeLayout stockRow;
      public LinearLayout tickerInfo;
      public Boolean isCategoryOpened = false;
  
      public ViewHolder(View itemView) {
          super(itemView);
          this.tickerSymbol = (TextView) itemView.findViewById(R.id.ticker_symbol_textview);
          this.companyName = (TextView) itemView.findViewById(R.id.company_name_textview);
          this.highlightBuy = itemView.findViewById(R.id.highlight_buy_view);
          this.categoryImage = (LinearLayout) itemView.findViewById(R.id.category_image);
          this.categoryLayoutParams = (LayoutParams) categoryImage.getLayoutParams();
          this.arrowImage = (LinearLayout) itemView.findViewById(R.id.arrow);
          this.categoryIconSeparator = (ImageView) itemView.findViewById(R.id.category_icon_separator);
          this.arrowSeparator = (ImageView) itemView.findViewById(R.id.arrow_separator);
          this.arrowIcon = (ImageView) itemView.findViewById(R.id.arrow_icon_imageview);
          this.stockRow = (RelativeLayout) itemView.findViewById(R.id.stock_row);
          this.tickerInfo = (LinearLayout) itemView.findViewById(R.id.ticker_info);
      }
  }
  

• onCreateViewHolder

  @Override
  public StockListAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
  
    Context context = parent.getContext();
    LayoutInflater inflater = LayoutInflater.from(context);
  
    View stockView = inflater.inflate(R.layout.stock_list_row, parent, false);
  
    return new StockListAdapter.ViewHolder(stockView);
  }
  

• onBindViewHolder

  @Override
  public void onBindViewHolder(final StockListAdapter.ViewHolder holder, final int position) {
    final Stock stock = mStocks.get(position);
    final int collapsedCategoryWidth = (int) mContext.getResources().getDimension(R.dimen.collapsed_category_icon_width);
    final int stockRowHeight = (int) mContext.getResources().getDimension(R.dimen.stock_row_height);
  
    //Reset holder status
    if (holder.isCategoryOpened) {
        holder.isCategoryOpened = false;
        holder.categoryImage.getLayoutParams().width = collapsedCategoryWidth;
        holder.categoryImage.setLayoutParams(holder.categoryImage.getLayoutParams());
        holder.arrowIcon.setRotationY(0);
    }
  
    holder.tickerSymbol.setText(stock.ticker);
  
    holder.companyName.setText(stock.name);
    holder.companyName.setSelected(true);
    holder.companyName.requestFocus();
  
    holder.categoryImage.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
  
          final int newWidth;
          final int startWidth;
          final int startArrowAngle;
          final int newArrowAngle;
  
          if (!holder.isCategoryOpened) {
              holder.isCategoryOpened = true;
              newWidth = holder.stockRow.getWidth() - holder.categoryLayoutParams.leftMargin - holder.arrowImage.getWidth() - ((LayoutParams) holder.arrowImage.getLayoutParams()).rightMargin - holder.categoryIconSeparator.getWidth();
              startWidth = collapsedCategoryWidth;
              startArrowAngle = 0;
              newArrowAngle = 180;
          } else {
              holder.isCategoryOpened = false;
              newWidth = collapsedCategoryWidth;
              startWidth = holder.categoryImage.getWidth();
              startArrowAngle = 180;
              newArrowAngle = 0;
          }
  
          Animation a = new Animation() {
              @Override
              protected void applyTransformation(float interpolatedTime, Transformation t) {
                  holder.categoryLayoutParams.width = startWidth + (int) ((newWidth - startWidth) * interpolatedTime);
                  //MAYBE PROBLEM HERE??
                  holder.categoryImage.setLayoutParams(holder.categoryLayoutParams);
                  holder.arrowIcon.setRotationY(startArrowAngle + (newArrowAngle - startArrowAngle) * interpolatedTime);
              }
          };
          a.setDuration(500);
          holder.categoryImage.startAnimation(a);
      }
  });
  

我将附上我遇到的错误示例。

当我第一次单击 View 时，onClick 成功运行，但如果我滚动然后返回到该 View ，则只有箭头翻转(这意味着 onClick 被调用)但 LinearLayout Width 不会被修改。

但现在真正奇怪的是，如果我点击另一个以前没有被点击过，或者(我猜)没有被回收的 View ，会发生以下情况:

所以我猜，宽度已设置，但未显示。

我真的不知道如何解决这个问题。

感谢您的帮助或其他想法!

这是我已经尝试过的:

• 将状态放入库存；
• 将监听器置于适配器之外；
• 将监听器放入支架内；

Answer 1

如果您是否已经点击该项目，请在您的商店类中将 1 个变量添加到存储值中..

像这样的插图，我在商店中设置了变量 isSelected :

 private boolean mSelected=false;

 public boolean getIsSelected(){
        return this.mSelected;
    }
    public void setIsSelected(boolean mSelected){
        this.mSelected=mSelected;
    }

然后在您的 onClick 方法中，只需在 if 条件之后添加 stock.setIsSelected(!stock.getIsSelected()) 并将您的 if 条件设置为从 stock.getIsSelected()< 读取 boolean 值 最后，只需从您的 holder 中删除变量 isCategoryOpened。

public void onClick(View v) {

        final int newWidth;
        final int startWidth;
        final int startArrowAngle;
        final int newArrowAngle;

        if (stock.getIsSelected()) {
            newWidth = holder.stockRow.getWidth() - holder.categoryLayoutParams.leftMargin - holder.arrowImage.getWidth() - ((LayoutParams) holder.arrowImage.getLayoutParams()).rightMargin - holder.categoryIconSeparator.getWidth();
            startWidth = collapsedCategoryWidth;
            startArrowAngle = 0;
            newArrowAngle = 180;
        } else {
            newWidth = collapsedCategoryWidth;
            startWidth = holder.categoryImage.getWidth();
            startArrowAngle = 180;
            newArrowAngle = 0;
        }
       stock.setIsSelected(!stock.getIsSelected())
        Animation a = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                holder.categoryLayoutParams.width = startWidth + (int) ((newWidth - startWidth) * interpolatedTime);
                //MAYBE PROBLEM HERE??
                holder.categoryImage.setLayoutParams(holder.categoryLayoutParams);
                holder.arrowIcon.setRotationY(startArrowAngle + (newArrowAngle - startArrowAngle) * interpolatedTime);
            }
        };
        a.setDuration(500);
        holder.categoryImage.startAnimation(a);
    }

如果我错了请纠正我:)