java - 在 recyclerview 中滚动时背景颜色或图像洗牌？

Question

我想知道当我向下或向上滚动时，我的图像和布局颜色会乱序，我使用 recyclerview 创建了 cardview。并设置图像(单击时更改颜色以了解其用户是否喜欢项目)和设置背景颜色(随机选择)到父布局以使 cardview 更具吸引力。但是当我滚动时1.图像改变位置的图像，2.布局背景自动变色。

我在这里发布我的适配器代码。

public class TOAdapter extends RecyclerView.Adapter<TOAdapter.ViewHolder> {
JSONArray jsonArray;
private String title;
private String image;
private ImageLoader imageLoader;
private String subtitle;
private String subti;
private Context context;
private ImageView clip;

public TOAdapter(JSONArray jsonArray) {
    this.jsonArray = jsonArray;
}

// Create new views (invoked by the layout manager)
@Override
public TOAdapter.ViewHolder onCreateViewHolder(final ViewGroup parent,
                                               int viewType) {
    // create a new view
    View itemLayoutView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.top_twenty_list, parent, false);
    final ViewHolder viewHolder = new ViewHolder(itemLayoutView);


    final Random random = new Random(System.currentTimeMillis());// We add 155 since we want at least 155 in each channel.// Then we add to it a random number between 0 and 100.
    int r = 155 + random.nextInt(101);
    int g = 155 + random.nextInt(101);
    int b = 155 + random.nextInt(101);
    int color = Color.rgb(r, g, b);

    viewHolder.frame.setBackgroundColor(color);
    viewHolder.layer.setBackgroundColor(color);
    clip = (ImageView) itemLayoutView.findViewById(R.id.ic_clip);
    clip.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            int iColor = Color.parseColor("#0000FF");

            int red = (iColor & 0xFF0000) / 0xFFFF;
            int green = (iColor & 0xFF00) / 0xFF;
            int blue = iColor & 0xFF;

            float[] matrix = {0, 0, 0, 0, red
                    , 0, 0, 0, 0, green
                    , 0, 0, 0, 0, blue
                    , 0, 0, 0, 1, 0};

            ColorFilter colorFilter = new ColorMatrixColorFilter(matrix);
            clip.setColorFilter(colorFilter);
        }
    });


    return viewHolder;
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(final ViewHolder viewHolder, int position) {

    // - get data from your itemsData at this position
    // - replace the contents of the view with that itemsData
    // myTypeface = Typeface.createFromAsset(context.getAssets(), "fonts/RobotoCondensedBoldItalic.ttf");


    try {
        JSONObject obj = jsonArray.getJSONObject(position);
        title = obj.getString("title");
        image = obj.getString("brand_logo");
        subtitle = obj.getString("sub_title");
    } catch (JSONException e) {
        e.printStackTrace();
    }
    viewHolder.txtViewTitle.setText(subtitle);
    viewHolder.subtitle.setText(title);


    if (imageLoader == null)
        imageLoader = AppController.getInstance().getImageLoader();
    String full_Url = "http://mycompany/assets/new" + image;
    viewHolder.thumbnail.setImageUrl(full_Url, imageLoader);
    viewHolder.btn_get_deal.setTag(position);

    viewHolder.btn_get_deal.setOnClickListener(new View.OnClickListener() {
        public JSONObject obj;
        public ArrayList<String> offerlist = new ArrayList();

        @Override
        public void onClick(View view) {

            Intent offerpage = new Intent(AppController.getInstance().getApplicationContext(), OfferDetails.class);
            Integer pos = (Integer) view.getTag();
            try {
                obj = jsonArray.getJSONObject(pos);
                offerpage.putExtra("jsonObj", obj.toString());

            } catch (JSONException e) {
                e.printStackTrace();
            }

            //offerpage.getParcelableArrayListExtra(offerlist);
            offerpage.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            AppController.getInstance().getApplicationContext().startActivity(offerpage);
        }
    });


    //viewHolder.txtViewTitle.setTypeface(myTypeface);


}

// inner class to hold a reference to each item of RecyclerView
public static class ViewHolder extends RecyclerView.ViewHolder {

    private final NetworkImageView thumbnail;
    private final RelativeLayout frame;
    private final RelativeLayout layer;
    public TextView txtViewTitle;
    public TextView subtitle;
    public ImageView clip;
    public CardView btn_get_deal;


    public ViewHolder(View itemLayoutView) {
        super(itemLayoutView);
        txtViewTitle = (TextView) itemLayoutView.findViewById(R.id.txttitle_toptwenty);
        subtitle = (TextView) itemLayoutView.findViewById(R.id.sub_title_toptwenty);
        thumbnail = (NetworkImageView) itemLayoutView.findViewById(R.id.thumbnail_topwenty);
        frame = (RelativeLayout) itemLayoutView.findViewById(R.id.frame);
        layer = (RelativeLayout) itemLayoutView.findViewById(R.id.layer);
        btn_get_deal = (CardView) itemLayoutView.findViewById(R.id.card_view);


    }

}


// Return the size of your itemsData (invoked by the layout manager)
@Override
public int getItemCount() {
    return jsonArray.length();
}

Answer 1

我已经创建了一个您要完成的工作示例。你遇到错误的根源大多是你不了解 View 回收。我现在不打算向您解释整个事情，但无论如何这里是示例:

---

例如，我为每一行使用了这个布局:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    android:id="@+id/background"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="80dp">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"/>

</FrameLayout>

我使用了这个模型:

public class ExampleModel {

    private final int mColor;
    private final String mText;

    public ExampleModel(int color, String text) {
        mColor = color;
        mText = text;
    }

    public int getColor() {
        return mColor;
    }

    public String getText() {
        return mText;
    }
}

这个 View 持有者:

public class ExampleViewHolder extends RecyclerView.ViewHolder {

    private final FrameLayout mBackground;
    private final TextView mTextView;

    public ExampleViewHolder(View itemView) {
        super(itemView);

        mBackground = (FrameLayout) itemView.findViewById(R.id.background);
        mTextView = (TextView) itemView.findViewById(R.id.textView);
    }

    public void bind(ExampleModel model) {
        mBackground.setBackgroundColor(model.getColor());
        mTextView.setText(model.getText());
    }
}

如您所见，Adapter 实现同样简单:

public class ExampleAdapter extends RecyclerView.Adapter<ExampleViewHolder> {

    private final LayoutInflater mInflater;
    private final List<ExampleModel> mModels;

    public ExampleAdapter(Context context, List<ExampleModel> models) {
        mInflater = LayoutInflater.from(context);
        mModels = models;
    }

    @Override
    public ExampleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        final View itemView = mInflater.inflate(R.layout.item_example, parent, false);
        return new ExampleViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(ExampleViewHolder holder, int position) {
        final ExampleModel model = mModels.get(position);
        holder.bind(model);
    }

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

然后你像这样使用整个东西:

final Random mRandom = new Random(System.currentTimeMillis());

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    final List<ExampleModel> models = new ArrayList<>();
    for (int i = 0; i < 100; i++) {
        final int randomColor = generateRandomPastelColor();
        models.add(new ExampleModel(randomColor, String.valueOf(i)));
    }

    final ExampleAdapter adapter = new ExampleAdapter(getActivity(), models);
    recyclerView.setAdapter(adapter);
}

public int generateRandomPastelColor() {
    final int baseColor = Color.WHITE;

    final int red = (Color.red(baseColor) + mRandom.nextInt(256)) / 2;
    final int green = (Color.green(baseColor) + mRandom.nextInt(256)) / 2;
    final int blue = (Color.blue(baseColor) + mRandom.nextInt(256)) / 2;

    return Color.rgb(red, green, blue);
}

---

这应该可以满足您的需求，您可以将其用作如何实现Adapter 的示例。